Home Design Patent

Question: I am working on a home design patent with interlocking pieces, searched US patents and nothing came up not even similar; zero results, I was on Alibaba today looking around for an Amazon business and thought why don't I do a search, something similar came back in the shape but they were using completely different material with completely different ways of locking the pieces together, will I be able to get a u.s. patent on my project?
Comment: George White's comment is important. You must search broadly with few terms at first. Also, use alternative terms as the patents might not use your nomenclature for their invention.
Comment: The answer is simple: it depends on the exact specifics. But from what you're saying it sounds possible to get one, if done correctly.
Comment: Thank You so much!
Comment: When someone says they did a patent search and found "absolutely nothing", my experience is that they didn't do a very good search. This is very common. A factor I've seen and experienced myself is that it can be hard to find something you would rather not find. The words you use to describe it may not be the  words others use. Do not tell the world more specifics. I took a stab at what you might be thinking - https://patents.google.com/patent/US8113840B2 and https://www.pinterest.com/mohhad96/interlocking. As you discovered with Alibaba, searching for prior art is not just searching patents.
Answer: To expand on DonQuiKong's comment, the answer is that you very well might be able to get a patent, but it isn't guaranteed. What you found on Alibaba represents prior art. For you to obtain a patent, your invention needs to be useful, novel and non-obvious. Useful is usually a given. Novel generally means it is different from any prior art. Non-obvious means that given the prior art the invention wouldn't be an obvious step from the prior art for someone skilled in the field. Since you can't tell us the specifics of your invention without jeopardizing its patentability. the best advice I can provide it to hire an actual patent attorney or agent. Only they can evaluate the patentability of your invention.
It is good that you did a patent search, but you need to search broader than just US patents. While another country's patent wouldn't keep you from manufacturing or selling in the US, it could prevent you gaining a US patent. In addition, it is very challenging for most people to do an effective patent search since you need to understand claim language to fully understand what is being patented. Many patent attorneys hire trained patent librarians to do prior art searches. Since you found a product that is similar, I would suggest searching for any patents associated with that product including all the patents assigned to the product's manufacturer. If you find an associated patent, then search all the patent's citations for other relevant patents. This can be an iterative process.
Comment: Thank you so much for your feedback! It really helps to get perspective.
Comment: If you find the answer acceptable, you can accept it by clicking on the check mark.

Home Design Patent


6 month baby. Breast to bottle

Question: I am struggling to transition from breast to bottle. He just won't take the bottle. I've tried different flows, different bottles, and given him to different people for feeding. Nothing seems to work. Also, it seems like the breast milk isn't filling him up. He is asking for it 7 times a night and then waking up very soon after each feed. He eats one bowl of Cerelac and rice each in the morning and afternoon but he is still wanting milk. The very few times he has taken the bottle he will sleep perfectly for 2 solid hours. HELP!
Comment: Welcome! Can you please specify what exactly you are asking about? You are listening many aspects that may or may not be related. Is it about a feeding method (breast vs. bottle), milk (breast milk vs. formula), satiation, sleeping through the night… Please take the [tour] and browse through the [help], especially [ask], then [edit] your post so that the community can better understand what exactly you are asking about and help in a meaningful way.
Comment: We found that temperature plays a big role. The bottle in our case was not warm enough. Making it just a little warmer made a huge difference.
Comment: You might want to get a lactation consultant. It's possible that he gets a bad latch or doesn't suckle well, which would explain why he doesn't eat enough to stay fuller longer at any given feeding.
Comment: Would it be breastmilk (i.e., same taste but different medium) in the bottle? Or formula? Answers may differ depending on what you are feeding.
Answer: Give it time.
Our kids all moved from breast at different times. They all did move when they were ready, not something you will find on a calendar...
One of them did breast and bottle in parallel, but he did want to eat a lot.
All 3 were high on the growth chart so they were always hungry (still are - they eat well).
Answer: I'm sorry to hear that he's having a rough time.
The good news is, he takes cereal.
Would it work to mix the formula with cereal so it's a watery soup and then spoon-feed him?
I'm not suggesting you give up entirely on getting him to drink the bottle, but it might help him in the in-between period.
You might also want to post your question on https://www.whattoexpect.com.
They have a huge community with a LOT of combined experience between all the mommy members.
Good luck!
Answer: Check into the issue of "excess lipase". It can cause the milk to taste bad unless you follow a certain procedure after pumping.

6 month baby. Breast to bottle


Qubit demands of Grover's Algorithm

Question: I have been puzzling over the fact that Grover's algorithm seems to require an exponential number of ancilla qubits in the input size $n$ in order to function. My reasoning is that at every step of the Grover iteration, the reflection operator $U_\omega$ relies on an ancilla qubit which takes on the value $0$ or $1$ depending on the value of $f(x)$ for each $|x\rangle$. But at the end of the iteration, we cannot afford to clear, replace or tamper with this ancilla qubit, because it is highly entangled with the rest of the system and will cause superpositions to collapse. Thus, it seems that at every iteration of the Grover subroutine, we must add an additional ancilla qubit, which remains entangled with all the other qubits as the algorithm runs. In other words, it seems that the qubit demands of Grover's algorithm should be $O(2^{n/2})$ to search $\{0,1\}^n$. Doesn't this make Grover's algorithm substantially harder to implement than the classical analogue, which only uses $n$ bits? In other words, aren't we trading a quadratic decrease in runtime for an exponential increase in memory requirements?
Comment: You're right, Grover's algorithm is substantially more difficult that classical search.
Comment: @user1271772: But then why is it considered an improvement on classical search? It seems like if the quantum version is less powerful than the classical version, it hardly deserves recognition.
Comment: It is considered an improvement by people who do not know better, or who want to make people think it's an improvement so that they can get funding or so that they don't need to learn how to do research in unfamiliar fields. I would call it a "potential improvement" in which the word "potential" depends on the ability to make quantum computers that are good enough. Currently it's not foreseeable that we will see that happen in the next 20 or maybe 70 years, unless a breakthrough discovery is made. For hardware, in ~30 yrs I only seem to see incremental improvements rather than breakthroughs.
Answer: The ancilla shouldn't be entangled with the main register after every iteration and the same ancilla qubit should be able to be reused for every iteration, in fact the ancilla's state shouldn't change at all due to phase kickback.
The ancilla-aided version of the Grover oracle is implemented as a controlled gate targeting the ancilla applied depending on whether a computational basis state on the main register is marked by the oracle or not, but the ancilla and the gate are such that the gate only applies a global phase of $\pi$ to it (multiplication by -1), implemented typically as either a $Z$ on $|1\rangle$ or an $X$ on $|-\rangle$. When the main register is in a superposition of both marked and unmarked computational basis states, the phase kickback created by this will result in the state of the ancilla being unaffected and remain unentangled and the portions of the main register's superposition that did trigger the gate (the "marked" ones) will have their phases reversed, which allows the diffusion operator to then reverse back and boost the magnitude of their amplitudes compared to the ones that were unmarked.
Comment: I think you're assuming that quantum computers can implement quantum circuits exactly as they appear in textbooks. In the real world CNOT|11> is not |10>, and qubits don't evolve according to e^(-iHt) with H being defined only by your circuit. Phase kick-back is a concept that is derived from assuming that qubits evolve according to simple Markov chains of matrix multiplication. That's not how they evolve though.
Answer: There is an explicit example of solving constraint satisfaction problems by the Grover's algorithm. It needs only a single ancillary spin. Although strong entanglement is generated during physical implementation of the oracle, the state of this ancillary spin is trivial at the end of each computation step.
https://arxiv.org/pdf/2304.10488.pdf

Qubit demands of Grover's Algorithm


Finding metadata about symbology in *.lyr file, data-source missing?

Question:
I have this lyr file which have a data source I don't know where is. When I set a new data source, it's the lyr file with all the symbology that gets replaced with the default values from the data source, no the other way around.
Is there any way to get the coloring codes (which has to point to values in a table from the data source) in the lyr file?
Answer: Simplest approach would be to create another feature class with same field name of original feature class and apply the symbology to this new feature class.
If you don't know the field name, then you have to go Python (Arcpy)
From your snapshot it seems it is a "unique values" symbology which fortunate is exposed to arcpy.
Here is a snippet to print your symbology information:
<code>import arcpy
mxd = arcpy.mapping.MapDocument("current")
lyr = arcpy.mapping.ListLayers(mxd, "layerName")[0]
if lyr.symbologyType == "UNIQUE_VALUES":
  print lyr.symbology.valueField
  print lyr.symbology.classDescriptions
  print lyr.symbology.showOtherValues
del mxd
</code>
you can copy & paste this code in ArcMap Python window
Comment: That is the problem, I don't know anything about the original feature class.
Comment: @2013US10 see the update answer


Unicodedecodeerror with runserver

Question: After setting up all what django requires, I tried the runserver command and I caught an error:

UnicodeDecodeError: 'utf-8' codec can't decode byte 0xcf in position
  8: invalid continuation byte

From:
c:\sue>python manage.py runserver
Validating models...

0 errors found
April 16, 2014 - 15:02:42
Django version 1.6.2, using settings 'sue.settings'
Starting development server at http://127.0.0.1:8000/
Quit the server with CTRL-BREAK.
Unhandled exception in thread started by <function check_errors.<locals>.wrapper at 0x0000000003890048>
Traceback (most recent call last):
  File "C:\python34\lib\site-packages\django\utils\autoreload.py", line 93, in wrapper fn(*args, **kwargs)
  File "C:\python34\lib\site-packages\django\core\management\commands\runserver.py", line 127, in inner_run ipv6=self.use_ipv6, threading=threading)
  File "C:\python34\lib\site-packages\django\core\servers\basehttp.py", line 167, in run httpd = httpd_cls(server_address, WSGIRequestHandler, ipv6=ipv6)
  File "C:\python34\lib\site-packages\django\core\servers\basehttp.py", line 109, in __init__ super(WSGIServer, self).__init__(*args, **kwargs)
  File "C:\python34\lib\socketserver.py", line 430, in __init__ self.server_bind()
  File "C:\python34\lib\site-packages\django\core\servers\basehttp.py", line 113, in server_bind super(WSGIServer, self).server_bind()
  File "C:\python34\lib\wsgiref\simple_server.py", line 50, in server_bind HTTPServer.server_bind(self)
  File "C:\python34\lib\http\server.py", line 137, in server_bind
    self.server_name = socket.getfqdn(host)
  File "C:\python34\lib\socket.py", line 460, in getfqdn
    hostname, aliases, ipaddrs = gethostbyaddr(name)
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xcf in position 8: invalid continuation byte

I am using Windows 7 x64, python 3.4 and django 1.6.2. What does this error mean?
Comment: Maybe host name consist of incorrect symbols
Comment: Possibly a configuration file is in a non UTF-8 character set?
Answer: This sounds like this Python issue. If your computer name has non-ASCII characters this will fail. You may:

Issue the runserver command with explicit host and port: python manage.py runserver 127.0.0.1:8000
Change your computer name to a string that only contains ASCII characters.
Answer: I just had this issue because I accidentally visited the site with https instead of http.  Switching back to http fixed it.
Answer: I hit this issue on python 3.4 with the following situation :

Server did have an ascii-only hostname (like host1)
The /etc/hosts file did not contain an entry for my hostname
There was no available DNS resolver (offline computer)

After adding the following entry to the /etc/hosts file, no further UnicodeDecodeError exceptions were thrown.
127.0.0.1 localhost host1

Unicodedecodeerror with runserver


looking at the piecewise definition why isn't the absolute value of x differentiable at 0?

Question: I understand how simple it is to see that the absolute value function is not differentiable at zero however by definition we have that the absolute value of $x$ is equal to $x$ when $x$ is greater than or equal to $0$, but that why is the derivative at zero not the derivative of $x$, $1$?
Comment: Can you find the left-hand derivative at zero? Is it equal to $1$?
Answer: You could just as easily have said:

however by definition we have that the absolute value of $x$ is equal to $-x$ when $x$ is less than or equal to 0, but then why is the derivative at zero not the derivative of $-x$, $-1$?

In more detail: the derivative is (by definition) a limit of a difference quotient, i.e. with $f(x)=|x|$ we have $f'(0)$ defined by
$$f'(0) =\lim_{h\to 0}\frac{|h|-0}{h}$$
I think many of us, especially when we are new to Calculus, tend to have an unconscious "right-handed bias":  when we think about an expression like $f(a+h)$ we naturally think of it as calculating the value of $f(x)$ at a point slightly to the right of $x=a$.  But the limit is a two-sided operation, and there's no reason to think of $h$ as a positive number.  In this case, it's true that as you approach $h=0$ from the right, the difference quotient is $1$.  However, as you approach $h=0$ from the left, the difference quotient is $-1$.  Because these values don't agree, the limit at $h=0$ does not exist.
Answer: Because from the fact that $x\geqslant0\implies|x|=x$, the only thing that you can deduce about the differentiablity of the aboslute function at $0$ is that the right derivative at $0$ is $1$. And $x\leqslant0\implies|x|=-x$, from which you can deduce that the left derivative at $0$ is $-1$. Since the left and the right derivatives at $0$ are different, the absolute value function is not differentiable at $0$.
Comment: why is it that we can only make deductions about the left and right derivatives? if the case includes zero then surely you could write it as an interval, say ( ∞ , 0 ] and this would include the derivative at 0.
Comment: Because the assertion $x\geqslant0\implies|x|=x$ only contains information about what happens on $[0,+\infty)$. SInce $0$ is the extreme left of this interval, the onlt information we can extract is therefore about the right derivative at $0$. That's all.


Is it legal not to have a working stopcock in the UK?

Question: I rent a ~50 year old terraced house in the UK, and had some plumbing work done recently. The plumber said the stopcock doesn't work, and so had to freeze the pipes to get the work done. This makes me nervous both for my own things and the insurance in case an accident should result in an unhindered flow of water. Is this something the owner is obliged to fix?
Answer: Your problem is not just that you don't have a working stopcock, but that you now know that you don't have one. Of course it's not illegal by itself, the problem is what is going to happen if you have an insurance case.
Your home insurance most likely has to pay for accidental damage. But any damage that would be caused by not being able to close the stopcock, when you knew it wasn't working, they could claim that this is due to gross negligence.
Whether they would succeed with that claim or not, I don't know, but fixing the stopcock seems to be a much, much cheaper solution.
PS. Seems I made a wrong assumption here - that it was your home, owned by you. The same reasons that would have made it a good idea for you to fix the stopcock obviously make it a good idea for the landlord as well. So I would make sure that you tell the landlord as soon as possible. If something goes wrong, and the insurance doesn't pay, your landlord would be responsible for the damage.
Whether it's legal to not fix the stopcock - that's a different matter. I thought you were the owner. You would have endangered yourself and your property. Nothing illegal with that. But with the landlord it's different; he wouldn't be endangering himself but someone else's property.
Comment: Thanks for the useful information regarding insurance, but this doesn't really answer the question as stated. I have to get approval from the owner to get *any* works done on the property, and before asking for this to be arranged I would like to know whether the owner or I would have to pay for it.


Raspbian ad hoc networking issue with wlan0 set to type ibss

Question: I am following the instruction given by How to setup an unprotected Ad Hoc (IBSS) Network and if possible with WPA encryption? but the probelm occurs when I get to the line
iw wlan0 set type ibss
An error happens:
command failed: Device or resource busy
I Am using Raspbian buster latest version.
Comment: Did you exec sudo ifconfig wlan0 down before?
Comment: Yes, I found the solution. I post it
Answer: The latest raspbian uses wpa_suppplicant, this needs to be disabled in order to change the wlan0 type. Run this command:
killall wpa_supplicant
Comment: Have you also tried just executing sudo ifconfig wlan0 down, then your cmd and then sudo ifconfig wlan0 up. This should also work.
Comment: Yes, first tried that.
Comment: Another thing to note is that apparently you can't add a virtual interface to pi (I'm using Zero 2) without sharing the channel. If you don't want to share channel you can just make the wlan0 interface itself as IBSS as in the link posted by OP

https://forums.raspberrypi.com/viewtopic.php?f=36&t=138730


Which UI Widget should be used for a "back to top" action on a list?

Question: I'm designing an android app with a long list, on which I'm implementing a 'back to top' action. My first go-to was a floating action button, but I'm wondering if I can use some other widget or some other kind of interface(action) that is intuitive. I checked out Google's Material Design but there isn't anything specific. Is there some better UI/UX for this function that is usually done?
Answer: Floating arrow button pointing "UP" when you pass a certain scroll height seems to be the standard way.
That behaviour is also used quite a lot in chat/messenger apps, especially when there are new messages and you have to scroll down to find them.
If you have long content a back-to-top link can prove useful. However, for normal content, users will usually scroll using the scrollbar and they often scroll at the top to gain access to the menu.
If you want to omit a "back-to-top" button I would suggest making your navigation/header fixed so at any point your users can navigate through the app with ease.
You can read more about 'back to top' and other in-page links on the NN/G website.
Comment: Thanks! I personally feel the nav/header thing isn't very intuitive, so I stuck with the button. I still don't like the way it blocks a part of my screen though(even though I made it more transparent and small, it still feels like it takes over a noticeable part of my screen). I want the user to focus on the list with minimal interference
Comment: It's all up to how long is your content. Users [https://www.nngroup.com/articles/scrolling-and-attention/](do scroll). However, how do you make things easier for them and offer a pleasant product? If your content is of average length I would say it is ok not to offer a "back-to-top" option.

However, if it is. Perhaps instead of a button you could add a subtle fixed bar at the bottom that takes them back to top past a certain scroll position. Or a link at the end of you text?

Ultimately you know if you need that function and it is up to you to experiment on the best way to approach this.


How do I switch first/last name order in the iOS address book?

Question: My contacts are arranged by last name first in my iPad and iPhone and I want to have them first name then last name. Where do I access the address book preferences?
Answer:
Go to Settings.
Scroll down and click the Mail, Contacts, and Calenders preference.
Now, scroll until you are under Contacts heading.
Select the Sort Order option.
Choose which way you want to sort your contacts.


RDP from Windows to Linux

Question: Today I wanted to make my RDP from Windows to OpenSuse. After successful setup and configuration I can connect to my RDP but can't make any changes or see any views on OpenSuse desktop. When I login as local VM (not RDP) I see folders on desktop and can make changes. Is there any ability to fix that?
Answer: For viewing desktop , You have some way:

VNC
set DISPLAY variable in your terminal.

NOTE: You don't have RDP in Linux as RDP server.

RDP from Windows to Linux


How can I copy and rename files with the same file name

Question: I have a directory structure that contains a number of files which are named the same as in:
  dir1/test
  dir2/test
  dir3/test
I want to find each test file and copy it to another directory with a unique (arbitrary) file name so I can analyze the data they contain.
There could be a large number of these similarly named files contained several layers deep in the directory structure. I can use find to locate the files but the renaming (using find) is alluding me.
Can anyone provide guidance on this issue?
Answer:
source_dir is root directory form where you want to search the files.
destination_dir is destination directory to where you want to copy or move your files
*.doc is your file name or file pattern to search for.

You can copy files with following command! note that --backup=numbered will create numerically increased suffixed file if file with that name is already in destination directory.
find /source_dir -type f -name *.doc | xargs -I '{}' cp --backup=numbered {} /destination_dir

You can move files with following command! note that --backup=t will create numerically increased suffixed file if file with that name is already in destination directory.
find /source_dir -type f -name *.doc | xargs -I '{}' mv --backup=t {} /destination_dir

You can also consider using these commands with sudo if you might have in search destination matching files belonging to other user.
If you want verbose output of these commands add add -v after --backup=numbered or --backup=t.
Answer: You can replace the / in the path with another character and use that as the new file name:
#!/bin/bash
for f in /dir*/*
do
    cp "$f" "${f//\//.}"
done

Comment: Can I integrate your answer into a find command? As in, find . -name FNAME -exec bash -c 'for f in {} do; cp {} "$f" "/tmp/somedir/${f//\//.}" ; done \;. I tried it and received modifier failed. Should this work?


Fixed point in a continuous function

Question: Suppose that $f$ is a function defined in $[a;b]$ to $[a;b]$ and continuous on $[a;b]$.
The problem is I haven't the definition of the function, this is more abstract, but even if how can I prove that $f$ would have a fixed point?
Comment: Do you know the intermediate value theorem?
Comment: Hint: define $g(x) = f(x) - x$.
Comment: yes but how can I use here this is very abstract.
Comment: I need a general proof not a special situation.
Comment: The hint is not to prove that $f(x)=x$, that is not possible. A fixed point is a root of $f(x)-x$, can you prove that this difference has a root?
Comment: You asked this [before](http://math.stackexchange.com/questions/211251/continuity-in-an-interval).
Answer: Note that a fixed point is when $f(x) = x$ or $f(x) - x = 0$. Consider the function $f(x) -x$. Can it be everywhere positive? Can it be everywhere negative? As it is continuous, it thus has to have a zero.
Comment: It doesn't really need to be f(x)=x it can have another definition and we can found f(a) = a; even if f(x)!=x; if you understand what I mean.
Comment: for example f(x)=x^2-3x+4 had a fixed point in 2; f(2)=2
Comment: pourjour, you are saying it doesn't have to be $f(x)=x$, and then you are finding that $f(2)=2$. In other words, you are finding that $x=2$ is a solution of the equation $f(x)=x$, which is exactly what Karolis and LevDub and N. S. are telling you to do.
Answer: A related problem. Here is what you are looking for Brouwer fixed-point theorem.
In the plane: Every continuous function $f$ from a closed disk to itself has at least one fixed point.
This can be generalized to an arbitrary finite dimension:
In Euclidean space: Every continuous function from a closed ball of a Euclidean space to itself has a fixed point.
A slightly more general version is as follows:
Convex compact set: Every continuous function f from a convex compact subset K of a Euclidean space to K itself has a fixed point.
An even more general form is better known under a different name:
Schauder fixed point theorem: Every continuous function from a convex compact subset K of a Banach space to K itself has a fixed point.
Answer: I think you can prove it using the properties of the real line.
If $f(a)=a$ or $f(b)=b$ then the result follows. If not then $f(a)\gt a$ and $f(b)\lt b$ try   using the continuity of $f$ to show that $\sup\{x\in [a,b]\space|\space f(x)\gt x\}$ is a fixed point for $f$.

Fixed point in a continuous function


How do I add a folder to the Library using a UNIX command?

Question: I need to add a folder to /user/username/Library/Application Support/Google, on a number of computers.  Is there a way to do it with a UNIX command in ARD, so I don't have to touch each machine?
Answer: The command to create a folder is:
mkdir "/Users/myuser/Library/Application Support/Google/MyFolder"

(you'll need to substitute your own folder name ofcourse)
Answer: It sure is!
mkdir '/Users/username/Library/Application Support/Google/whatever'
Replace 'username' and 'whatever' appropriately, of course. Also, note that if anything in the path contains single quotes (apostrophes), you'll need to replace each one with '\'' – I'm using single quotes here to take care of any other quoting issues, and this will end the quote string, put in a quote, and start another (Single-quoted strings don't accept any form of escape, even escaping a single quote!).
For more information on this command, type man mkdir in Terminal.
For more information on shell quoting, type man bash in Terminal, then use /quoting to search for "quoting"—this should get you to the appropriate section.


How do I make a pull out drawer?

Question: I am in the process of making some drawers for one of my cabinets. I have a rough idea of how I will do it, but if someone who has made this kind of drawer could tell me what all I will need it would be very helpful for me.
Comment: Have you considered buying the drawers from a local millwork shop? I say this after hearing the same thing from my woodworking instructor, who has a day job as a high-end cabinetmaker: they buy drawers rather than making them.
Comment: I checked with them and each drawer costs around $70. I need 4 drawers. it comes to $280. I can buy a new vanity for around $350. The thing is i have lots of wood and i want to use it.
Comment: what tools do you have? Do you have a router table?
Comment: I have circular saw. Drawers are for cabinet. I have made one drawer already :).  Yet to assemble it to the cabinet. Nothing fancy but just wanted to make something functional to use wasted space.
Answer: Adam Jaskiewicz covered the basics, but I'll add a few comments. I've built exactly one "furniture grade" drawer, but several "shop grade" drawers. And I've never done a dovetail joint. So take what I say with at least one grain of salt.
The basic drawer box is four sides with a groove cut into the inside for the bottom. Depending on use, you can use 3/4 plywood or 1" dimensional lumber. You could probably get away with 1/2" plywood for small drawers (for example, in a dresser), but I think the 3/4 is a better choice if you have anything heavy inside. The  can be 1/4 plywood, and it's not glued to the rest of the drawer.
You can use either wooden slides (basically, a groove cut into the back of the drawer and matching strips of wood that run front to back on the piece), or a side-mounted metal slide. I recommend the metal slide, particularly for a kitchen cabinet, which will be fully extended. I really can't recommend using wooden slides: they may be more "pure," but they're a lot less functional (and yes, for my one furniture-grade drawer, I used wooden slides; it doesn't get a lot of use).
Here's a page that describes the basic cuts for a drawer: http://www.knottyplans.com/index.php?page=200422&ref=kp32ap98f (it was one of the top hits on Google that looked reasonable).
The biggest issue that you'll face when building a drawer is how to join the front and sides. This joint will take all of the stress of opening the drawer.
The traditional approach is to use a dovetail joint. If you have a router and a dovetail jig, this is a great approach. It's particularly good if you're making a lot of drawers, and can set the jig once for all of them. You can also make dovetails with a backsaw (or better, a nokogiri saw), but you'll need lots of patience and practice.
Although a dovetail joint is traditional, a finger joint is almost as strong, and you may can make it using a table saw (assuming that you have a dado blade and a vertical jig). There are several other types of joints of varying strength; Fine Woodworking did an article on them several years ago.
If you go the dovetail route, the front panel of the drawer should be the width of the opening minus whatever you need for the slides. In furniture applications that have slides, there's typically a "face" front that's attached to the structural front, and covers the gaps. The alternative is a half-blind dovetail.
However, if you're looking to create drawers that live inside a cabinet (and are therefore hidden behind a door), you can get away with an alternate joint, in which the front panel is held between the side panels, and is screwed in place:
<code>||==front==||
||         ||
</code>
In this approach, all of the strength in the joint comes from the mechanical fasteners. So don't skimp: go thick (#8 or better), long (1-1/2 or better), and repeated (one screw per inch). You could also use finishing nails, although they do not provide the flex resistance of screws. Do not rely on glue; there is no surface area for the glue to bond (as far as I'm concerned, end-grain is useless). Oh, and pre-drill the holes.
Comment: Good answer. I would recommend a 1/4" depth of cut along the sides for the bottom panel, increased to 3/8" with 3/8" ply if it's used to store heavier stuff (like in the pic). Also you'll have to increase the thickness of the bottom ply if the draw is considerably longer along one dimension than the other (e.g., dresser draws that are wide, but not too deep). Thin plys cannot resist the bending moment and will sag in the middle. Eventually this sag will "set in" and make it difficult to open/close it. Sometimes, if the depth of cut is insufficient, it might even pop out from the side grooves.
Answer: Well, it's like any other drawer, but the front is sized to fit completely into the cabinet rather than against the front of the frame.
It looks like that particular drawer has slides that mount to the underside of the drawer, like these (not an endorsement, just an example with a good picture).
Comment: You're correct (so +1), although drawers are not "simple boxes." The joint between the front panel and the side has to be stronger than other boxes, because it has to take the stress of opening. That's the reason that front joints are typically dovetails (although there are alternatives) while back joints are usually simple rabbets.
Comment: Point taken, I mean to say it's the same as any other drawer (other than the obvious considerations to keep from interfering with the door).

How do I make a pull out drawer?


France Schengen Visa; Want to Travel to Italy Next Month

Question: I was recently issued a France Schengen Visa (multiple entries); however, I want to travel to Italy next month...will I need to apply for a Spanish Schengen Visa or can I use the France Visa to go to Italy?
Comment: I'm not sure what you're trying to ask. It's a Schengen visa which would mean you can go to Italy using it. Even if you couldn't why would you apply for another one with the Spanish Embassy?
Comment: Thanks for your response.

Sorry if I wasn't clear...What I meant was I was issued a Visa by the French Consulate and I'll be traveling to Paris this month, for a week.

After I return home, I would like to go to Italy next month.

I've been doing research and so far what I've read basically says "I need to spend most of my vacation time in the country that issued the visa"
Comment: Further to my original post, I meant an Italian Visa...not Spanish
Answer: The Schengen visa is valid for all countries of l'espace Schengen; you can use it for entering l'espace Schengen at any border. If it has not expired, you are ok. But the national authorities can still refuse you entry for another reason: you are coming from a dangerous country, you have an arrest warrant on your head, etc ;)


Mediawiki and databases

Question: Is there a way I can create a database from which to pull data into my mediawiki table? Or is there a way to have a database like drupal and place a mediawiki type interface on it?
Answer: There is no way to directly do this in stock MediaWiki, although you can fake it up somewhat with templates. For example, you could can a template something like this:
<code>{{#switch:{{{key}}}
 | key1 = value1
 | key2 = value2
 | key3 = value3
 ...
}}
</code>
Template:NUMBEROF/data on the English Wikipedia is an example of this style (with two levels of keys).
Or you can create a set of templates, one for each "record", that each take an "output formatter" template as a parameter and pass that output formatter a named parameter for each column in the record. The Country data templates on the English Wikipedia are an example of this pattern.
Or you could combine the above two styles, with one parameter to select the row (as in the first style) and a second to provide the output formatter (as in the second).
If you don't mind installing extensions, you could use the Labeled Section Transclusion extension to transclude sections of a data page. Or you could install the Semantic MediaWiki extension, which I hear allows all sorts of querying of data from the wiki's pages. Or you could install one of the many Database extensions that may allow you to do what you want. Or you could write your own database extension.
Answer: You could also have a look at http://www.mediawiki.org/wiki/Extension:Data_Transfer, which do not require Semantic MediaWiki even though it's written for use with SMW. (If you use SMW there are, as noted in an earlier reply, plenty extensions and built in options.)

Mediawiki and databases


Can I use a non "me.com" address to send email with iCloud?

Question: I will  be buying an iPad and will want to use iCloud.  However, I want to use a non "@me.com" address to send email from/reply to.  Is this possible when you sign up for iCloud?  Thanks
Comment: @ChapHarrison - that should be a separate question also as non Apple specific look at and try SuperUser
Comment: I wonder if someone could clarify the distinction (if there is one) between where email is actually sent from versus the address the recipient sees when she hits "reply" or "add to contact list."  I want my email to be sent via iCloud's SMTP servers, so that a copy gets put into iCloud's SENT folder, but I want recipients to only see my pobox.com address for purposes of replying or adding me to their contact list.  It doesn't appear that iCloud lets you send email via its SMTP but specify a different "Reply-to" address.
Comment: Is this for OSX mail or iPhone/iPad? The former is easy the latter problematic
Answer: Using iCloud doesn't necessarily means you'll have to use Mail on iCloud. You can still use your current mail provider to send/receive email on your iPad. Providing you can connect to your current provider using IMAP, Exchange or POP.
You can also create your iCloud account without having a @me.com address. I use my @gmail.com address as my Apple ID to connect to iCloud to sync Contacts, Calendars, etc.
Comment: I use a "@pobox.com email address which is a forwarding service that I pay for.   I simply tell my pobox.com account where to forward email to. Therefore I never have to inform anyone when I change my email address.  All email sent from Mail on my iMac shows sent from my pobox.com address.  I use a gmail account as my server (provider?).  I would like to continue to use my pobox.com address when sending email from Mail or from my new iPad and from iCloud.  Will I be able to use this forwarding address, pobox.com to sync email through iCloud.  Thanks for your help.
Comment: Loic: Technically you're not using your gmail address to sync via iCloud. Your gmail address is your Apple ID and it's what you're using to log into iCloud.
Comment: Since it's acting like a real email address, I don't see any issue. They'll probably send you an email to this address to confirm it exists and then you'll be able to log in with it.
Comment: @Richard right, I tried to clarify it in my answer, thanks.
Answer: If you use iCloud mail, then you can not use any other email address than me.com.
You can forward the mails from your old email to the me.com, but if you send an email from iCloud then the sender will be me.com.
This is a serious issue with iCloud, and I personally hate it.
Comment: Wow.  If that's true, I hate it, too.  Pobox.com has won my trust, whereas Apple hasn't (after pulling "free" mac.com email addresses).  I want to send from iCloud, simply because of its ability to capture and propagate my "Sent" mail, but I want my official email address to be my pobox.com address.
Comment: @aloponen The other answer here seems to contradict what you're saying: http://apple.stackexchange.com/a/32404/20489
Answer: Yes you can.
Because of security [mainly spam and phishing] issues, respectable outgoing mail (smtp) server operators will only allow you to send mail from an email address and domain that they know you have the right to use.
This isn't just picky,  it's an essential part of the mechanism that has cut down SPAM.  Apple have no way of knowing whether you have the right to send from firstname.lastname@example.com. If you haven't that right, and Apple lets you use it to spam, then they are likely to end up with their servers being blacklisted and then none of us can send email.  Hence the restriction.
But your domain service provider has that knowledge.  They are already probably forwarding you incoming email, or mapping your incoming email server address across to Apple. Ask them if they have an outgoing smpt server that you can use to send mail,  and use it rather then Apple's outgoing server.
This may seem like a hack, but it is actually a perfectly rational setup.  The outgoing email will still get put in your iCloud out box, so there is no downside.
What would be nice is if Apple would take on the whole domain name management issue.
Comment: That is not using iCloud but is then using your domain service provider's SMTP which is not necessarily available if you move around
Answer: You can, but it's a bit of a hack.
You can choose to use an different SMTP server to the normal one, as is the SMTP server for iCloud that rejects the use of an email address that doesn't match up.  You can point it to a Google GMAIL server, and then get Google to change the "send from" address to match what you need to use.
Answer: No - iCloud servers will not send "spoofed" email so you'll need to arrange a second server to receive that email and send it.
There are several ways people configure this, the popular ones being:

configure an alternate SMTP server for outbound mail by setting up iCloud manually
use DNS and a proxy to handle the traffic
setting up two accounts on iOS / Mac and letting iCloud send from the alternate account.
Answer: In my view, the answer is simple: when you setup your iCloud account you can use whatever email address you want, (I have setup iCloud accounts with Yahoo.com email addresses as well as an iCloud.com email address).
Comment: We don't test people before they can ask and answer, as we are a very open and participatory site. Not all people are alike, so some consider two accounts as one, some don't mind splitting the inbound and outgoing settings, others consider this a simple NO.
Comment: you are right... however i saw the answer clearly, but yes you are right!


Will my comic reader app violate Comixology patent?

Question: I am developing an app for iOS devices which has almost the same guided view type reader for comic panels. There are a lot of posts on the web about fights between Marvel and Comixology regarding the patent of this viewer. I was wondering if my reader app can violate the patent guidelines. Secondly, if it does, still in wiki the technology has been written as "patent-pending"and if I can publish my app right now, will It still be an offensive app?
Comment: Welcome to Ask Patents!. You may have reached the site from a button on google patents but that did not insert the patent document number you are referring to into your posted question. Please edit your post with the patent number in question.
Comment: Hi George, thanks for your comment. I am a developer and have no idea how this patent thing works. I have almost finished my app and while I was getting ready to upload, I came across a post on wiki regarding the patent filing of comixology. It really was frustrating. So I posted the question here. I googled a lot to find patent number as you have asked but couldn't find it. Can you please suggest any URL where I can find this patent number?
Comment: A good way to search patent information is at http://www.google.com/patents. There is also a google advanced patent search (google it). I put comics in the primary search box and the name of the Comixology CEO in the inventor box. The search found Systems, Methods, and Media for Presenting Panel-Based Electronic Documents US20100318895
Comment: @Ranadhir - I'm curious, did you release your app? were you approached by Comixology or other to take it down?
Answer: Systems, Methods, and Media for Presenting Panel-Based Electronic Documents
US 20100318895 is an application, not yet an issued patent. Some of the web articles that mention it also note that Marvel (via Disney) has an issued patent US 8301999 that covers similar territory.
The entire history of the prosecution of any recent patent or application can be seen at USPTO Public PAIR. The current status of the Comixology application seen there is:

It has had a long history now of many rejections and corresponding claim amendments and arguments. Anyone can follow the progress there. Unless and until a patent is granted its owner has no right to stop anyone. Of course, once issued, the fact that something is already shipping isn't relevant to whether or not it infringes.


Passcode reset without factory resetting phone

Question: My girls put a passcode on my phone. If I try and guess 1 more time it will factory reset. Any ideas?
Comment: Welcome to Android Enthusiasts, Christina! Our [locked-out tag-wiki](https://android.stackexchange.com/tags/locked-out/info) should get you started. You're not the first one with that issue, so we collected some first-aid there.
Answer: Your best shot is to use the Android Device Manager to force a temporary password. Go ahead and Google it. It should be the first result. This is the Google equivalent of find my iPhone.
Once this is open, sign in using the Google account that's associated with the phone. You should be able to locate the phone, but what you want is the lock function. Set a different password you know with a message. When the phone displays that message, it's safe to unlock the phone using the temporary password you just set. From here you can go into the phone's settings and disable the password.


Is it okay to replace the Relief valve on a water heater, or do I need to get a new water heater?

Question: What happened was my wife smelled a different kind of odor.  I had a very good idea it was the water heater.  I opened up the compartment, and water was trying to come out of the pressure relief valve.  Water was all over the tank and the floor.  I checked the circuit breakers, one of the four were tripped.  I turned off all four and the box was pretty warm.  I went back and checked things out.  As I mentioned,the water ran down the front of the tank, both covers came off, water ran into the electrical parts, causing a short lived fire, which scorched areas on the outside of the tank.  I don't see it leaking water anywhere else. So I am back to asking, it is possible to just replace the Pressure Valve on the tank, or do I need to replace the water heater in it's entirety?
Comment: Water coming out of the pressure relief valve is normal for a fault state where pressure inside the tank is high enough to be purposefully relieved through the pressure release valve.  The short answer to your pointed question is YES, you can replace a relief valve.  But you have more problems than just the relief valve that you (or paid professional) need to solve to ensure safe operation of the existing water heater.
Comment: you might have a bad thermostat or a shorted element those things should be evaluated prior to throwing parts at it.
Answer: Water ran into the electronics of the heater and caused a small fire?
Yeah, probably going to be cheaper and easier replacing the whole thing than trying to figure out every part that damaged by that.  Especially since it had to be manfunctioning in the first place to overheat like that.
Water coming out the relief valve like that can indicate a serious malfunction - that valve isn't the whole problem. It is what makes the tank leak instead of explode.


Addressing un-level floor when using ceramic tile

Question: I am refinishing my bathroom, and a near-future task is flooring. I'm going to be using the Schluter Ditra product rather than hardiboard and I've built up the floor and subfloor for a combined thickness of 1-1/8" (or so). There is a small dip toward the middle of the floor of roughly 1/2" that mostly levels out by the bathroom door. Should that dip be leveled out with a leveling compound before applying the Ditra, or will using thinset to compensate be sufficient? The span of the dip is around 5' long by about 3' wide (width of the wall to the tub), with the deepest part being about 1/2".
Answer: If you have a good solid base, you can use a modified thinset, the same material to lay the Ditra into. Use a straight edge to screed the thinset over the low spot of the floor, do not sweat the "rake" marks left by the screed. If any "tags" occur from using the screed, they can be scraped off and vacuumed the next day. Then set the Ditra. The Ditra otherwise may not sink into the depression of the floor and get a good bond to the substrate. Also, the flatter you get you floor to start, the easier it will be to get the tile to lay in plane with the surrounding tile.
Answer: Absolutely, otherwise your ceramic tile will crack.  You'll need to smooth it out someway.  In fact, it would be smart to put type of sheeting down under the Ditra down if you can.  That way you know it will be flat.
Comment: What type of sheeting should be put down under the Ditra?
Comment: It depends on how bad the unevenness is.  You could use 1/4 inch lauan(very smooth).  Or even 1/2" plywood if you need something more rigid.  If you do go with the plywood, make sure it has a nice smooth side without knot holes.


Guidelines for vs Guidelines to

Question: Could you please explain to me the difference between Guidelines for and Guidelines to?
Comment: I am developing guidelines **for** doing XYZ.  When I've completed the task, I'll give the guidelines **to** my boss.
Answer: Do you have a particular example?
Personally I would use "guidelines for" in most situations, when referring to whatever the guidelines are for. "Please see guidelines for using the pool" "follow these guidelines for gram staining" "Here are the guidelines for evacuation" In all of these scenarios 'to' wouldn't sound right (though I can't pinpoint why).
I would use 'to' in the same way fixer1234 has commented, showing movement/transferal of the guidelines and i'm sure there are other contexts it would fit, this may be one of those times where English has too many rules and exceptions for most people to keep track of.
Answer: Two sentences from Britannica Dictionary

The government has issued new guidelines for following a healthy and balanced diet.
Here are some basic guidelines for helping you choose a dishwasher

Amongst 23 examplary sentences on OALD there isn't a sentence with 'guideline to something'.
I'm tempted to say that 'guideline on something' is another option. See the sentences on Cambridge Dictionary. So I usually prefer to write 'guideline for someone/something' and 'guideline on something'. Here are two examples from LDOCE

a new set of guidelines for teachers
guidelines on the employment of children

However, it would've been better if you'd provided a specific context/situation for your question.

Guidelines for vs Guidelines to


SQL Server 2008 Authentication mode changed on its own

Question: This morning we experienced an issue where our production server seemed to decide to change from Mixed authentication mode to Windows only authentication of its own volition. I was curious to know if any of you other DBAs out there had ever experienced this or might be able to point me in a good direction to try and make sure this doesn't happen to us again. The only other thing that seemed to be going on database wise, beyond typical use, was that the transaction log had just completed a backup.
Answer: The chances that the Authentication Mode changed on it's own is pretty near zero. More likely, it got changed by accident.
This is a change that requires a restart of the SQL Server service in order for it to take effect. What likely happened is that the Authentication Mode was changed sometime since the last restart (which could have been months ago)--then, when the instance restarted, the change "suddenly" took effect seemingly on it's own.
This particular configuration is stored in the registry, so if you have OS backups of your server, you could do some research to go back in time to try to determine when it changed.
Answer: I would check the server log if you can, I would definitely setup a DDL trigger to alert you when it changes.
I'm skeptical that it changed on its own, but I found a few articles showing that you can look at the registry to view it's auth mode and it makes me wonder if the auth mode was changed at the registry / server level and not the SQL Server level.
Here's the registry and code to view the registry level:
<code>DECLARE @AuthenticationMode INT
EXEC master.dbo.xp_instance_regread N'HKEY_LOCAL_MACHINE',
N'Software\Microsoft\MSSQLServer\MSSQLServer',
N'LoginMode', @AuthenticationMode OUTPUT

SELECT CASE @AuthenticationMode
WHEN 1 THEN 'Windows Authentication'
WHEN 2 THEN 'Windows and SQL Server Authentication'
ELSE 'Unknown'
END as [Authentication Mode]
</code>
Source
Here's another topic about the registry. I would probably set up a powershell script that can check every 5 min and see if it's set up correctly. If not, I'd have it change it. I'd look through the server logs and see if that shows any authentications to the server.
With the powershell script, if you make it log the results each 5 min and provide a datestamp, you'll be able to pinpoint the time it changes if it changes again. Perhaps it's a GPO update?
More on the registry level.
Script to change the registry.
One more note, it appears you need to restart for this change to take affect. Pinpoint when the server restarted last, I'm guessing you can find some activity leading up to that.


Handling Multiple requests for WCF Service in Silverlight application

Question: I have a number of operations in my WCF Service that have been decorated with the following attributes
[OperationContract(AsyncPattern = true)]
IAsyncResult BeginSomething1(...)
Response EndSomething1()
[OperationContract(AsyncPattern = true)]
IAsyncResult BeginSomething2(...)
Response EndSomething2()
I notice that no matter how I configure my WCF service I can never get
BeginSomething1 and BeginSomething2 to be running simultaneously together.
That is say I call BeginSomething1 at the client first,  BeginSomething2 does not appear to run at the server until EndSomething1 completes.
My WCF service is made to have AspNetCompatibilityRequirements set to true so Im just wondering if this has something to do with it...
It may require some substantial work if I am required to turn this off so was just hoping if there was a workaround?
Thanks
Answer: Couple of questions for you:

What do you have the WCF Throttling configured to on the service?
On the client, are you chaining the requests?  Make sure you're not waiting for the completion of the first call.
Comment: Yes throttling is set to 50 and other concurrent porperties


Permutation group of Satake parameters

Question: Let  $L(s)=\prod_{p}L_{p}(s)$ the Euler product of an L-function in the relevant right half-plane. As  $ L_{p}(s)=\prod_{j=1}^{d}(1-\alpha_{j}(p)p^{-s} )^{-1}$, the permutation group  $ G_{p}$ of the Satake parameters  $\alpha_{j}(p) $ preserves  $ L_{p} $. Which results are known about the general structure of  $ G_{p}$?
Answer: This is a silly question. The Satake paramaters $(\alpha_1(p),\ldots,\alpha_d(p))$ can be more precisely thought of as a conjugacy class in $\mathrm{GL}_n(\mathbb{C})$. In particular, the Satake parameters are, by definition, only defined up to permutations: really, you should think of $(\alpha_1(p),\ldots,\alpha_d(p))$ being the same Satake parameters as $(\alpha_{\sigma(1)}(p),\ldots,\alpha_{\sigma(d)}(p))$ (this makes a lot more sense at the level of representations of $\mathrm{GL}_n$ over local fields and the Satake isomorphism, but that would take us too far afield).
So you are just asking "what is $S_n$, the group of permutations on $n$-letters?"

Permutation group of Satake parameters


Financial advice on the big 3

Question: I recently graduated in December and have been working for the past 5 months. Since then I have saved 13,000. Now here is my conundrum, I am getting married in 6 months ($10,000), we are currently looking for a house and to top it off my car just died this week causing me to look for another. So my question how do I deal with looking for a car? I can buy a cheap car and hope it lasts and buy a new one in 2 years or I can put a 6,000 down payment on something close to 14,000 and drive it longer. I have no idea what to do.
(Edit: I make 50000 a year)
Answer: Car
If you can afford $6000, there is no reason not to buy a car outright for $6000.  It won't be new or luxury, but it should easily get you to and from work, which would seem the biggest issue.  At that price, you are paying enough to get something decent and not so much as to be really out of pocket if it fails.
Consider this.  You pay $14,000 for a used car and get a wimpy warranty.  You're out $6000 immediately and paying another $8000 plus interest over time.  If there is a major problem that is not covered by warranty, you might put another $3000 into it in a year or two.  You can't really avoid this, as you'll still owe money on the car.  So you might be forced to pay $17,000 for three years of car usage.  That's almost $6000 a year.
If you buy a $6000 car instead and have a $3000 problem in a year, you can junk the car.  You'll have paid the same $6000 for a year of car of usage.  And a lot of the time you'll get more out of it.  Even if you pay the $3000 and get another year out of it, you still only paid $4500 per year rather than $4667 per year that you would pay for three years of a $14,000 car with no repairs.
I've paid as little as $1500 for a car and gotten multiple years out of it.  There's no guarantee with a more expensive car.  Perhaps you'll get a year warranty with a $14,000 car, but that won't cover wear items like brakes.  You basically will have coverage of the drivetrain (engine, transmission, axles) and some other things.  The warranty also won't last the full time that you want to own the car.
Also remember that payments will eat into your savings.  Currently you are saving about $2500 a month.  So you expect to save another $15,000 before the wedding.  Car payments would tend to come out of that amount.  Insurance will also be more expensive, as the lender will insist on comprehensive and collision.
$13,000 + $15,000 = $28,000 savings.  You will have $28,000 - $6000 = $22,000 saved by the time of the wedding.  After the wedding, you'll have $22,000 - $10,000 = $12,000.
House
You have $12,000 to spend on a house downpayment after the wedding and car.  If you pay 20% down, that's a $60,000 house even if we ignore fees (sometimes the seller can pay them).
I would expect the rent on a $60,000 house to be around $600 a month.  You might find yourself better off if you rent for a year and then look to buy.  Assuming $2500 free money a month, after $700 rent you might have $1750 (adding another $50 for insurance).  That would be another $21,000 in savings.  $33,000 is a much better downpayment than $12,000.
If you make $50,000 a year, I wouldn't suggest paying more than $20,000 of that for housing costs.  So even if you can get a mortgage with less than 20% down, you should still be careful not to overleverage yourself.  And remember that mortgages with less than 20% down will usually charge you an extra monthly fee as private mortgage insurance (PMI).
Make sure that you count all the payments.  This means not just principal and interest but taxes as well.  Also remember to budget for things that you may not be paying now, e.g. utilities and groceries.  Make sure that you're withholding enough taxes.
Wedding
$10,000 seems reasonably cheap for a wedding.  You could get it down more by just doing a justice of the peace wedding with no ceremony, but if that's not what you want, don't do it.  You are almost certainly going to buy other cars.  Most people buy more than one house (particularly if your first house costs only $60,000).  This could be your only wedding.  Budgeting enough to cover the important guests makes sense.
I would say that the biggest worry is that this may not be enough.  Don't expect fancy extras at that price.
Comment: Re "...no reason not to buy a car outright for $6000", yes, there is.  Buy a car outright for $3000 (or less!) and have $3000 left :-)
Answer: The first thing you need to do when budgeting out big expenses is to find 1) what can and can't wait, and 2) what will provide the most utility.
Presumably, your wedding is non-negotiable, therefore you really have $3,000 of your $13,000 savings available to use. Just a note here that weddings are rarely under budget or even on budget, so make sure your have some "wiggle room" when it comes time to pay for that.
Buying a house (with your current available savings of $3,000) is probably not going to be in your best interest. With such a small down payment you will struggle to find financing and would most likely end up paying a much higher interest rate on your mortgage, or signing on for a mortgage longer than you may want. Because renting is presumably an option, buying a house should not be the highest priority.
I'm assuming that you use your vehicle every day to drive to work and that transit or biking would take too long or be too much hassle. Therefore it would seem that a vehicle has a very high utility and should be prioritized. In general, it is better to buy a car that is reliable and will last at least a few years, and will have some resale value when you get rid of it. Therefore, it is not in your best interest to buy a beater and have to repair it constantly for the next year or two before it dies.

I can put a 6,000 down payment on something close to 14,000 and drive it longer

Not sure where that $6,000 number is from but assuming you have $3,000:
I would recommend buying a nice vehicle, leveraging your down payment to find something reliable and comfortable for your uses. With $3,000 you might be looking in the $6,000 to $12,000 range, which would give you a decent, reliable vehicle.
I hope this helps answer your question.
Answer: How much of the wedding are you covering?  Half or all?  If half you have 9k to buy a car if all only 3k.  You can probably save some money in the 6 months prior to the wedding so, that is also included in the amount you can spend on a car.  At this point in your life you have no business getting a car loan.
It is a bad idea to buy now even if your 13k was dedicated for a down payment.  Start your career and get a feel for where you would both like to live.  Rent for a year or two.  In that time you can save an emergency fund and a down payment.  Only then will you be in a position to buy a home.  (Assuming that you do not have other consumer debt or student loans.)

Financial advice on the big 3


Edit Record Type in Custom Object

Question: I have a custom object and inside that there is this standard field named  Record type. It is a picklist. There are 4 options in the picklist and by default it is set to Drop Ship Purchase Order. I want to change that to Internal Purchase order.  I don't see any picklist option here.
Answer: The default record type is defined per profile. So for each profile you want you use, go to the object settings for the object and choose the "Default Record Type".
For example:
Comment: 1) Profiles are listed under Setup -> Manage Users -> Profiles. 2) Every User is a assigned to a profile so you only need to set this in as many profiles as you are using (at a minimum 1). You can see the profiles assigned to your users under Setup -> Manage Users -> Users.
Comment: **1st question:**: where is this object setting located ? I could not find anywhere in my object page. **2nd question:** So u mean if i am logged in and I change it to XYZ and if another person logs in with his credentials he the change won't reflect in his.

Edit Record Type in Custom Object


What is a stored procedure?

Question: What is a "stored procedure" and how do they work?
What is the make-up of a stored procedure (things each must have to be a stored procedure)?
Answer: Stored procedures are a batch of SQL statements that can be executed in a couple of ways. Most major DBMs support stored procedures; however, not all do. You will need to verify with your particular DBMS help documentation for specifics. As I am most familiar with SQL Server I will use that as my samples.
To create a stored procedure the syntax is fairly simple:
CREATE PROCEDURE <owner>.<procedure name>

     <Param> <datatype>

AS

So for example:
CREATE PROCEDURE Users_GetUserInfo

    @login nvarchar(30)=null

AS

    SELECT * from [Users]
    WHERE ISNULL(@login,login)=login

A benefit of stored procedures is that you can centralize data access logic into a single place that is then easy for DBA's to optimize. Stored procedures also have a security benefit in that you can grant execute rights to a stored procedure but the user will not need to have read/write permissions on the underlying tables. This is a good first step against SQL injection.
Stored procedures do come with downsides, basically the maintenance associated with your basic CRUD operation. Let's say for each table you have an Insert, Update, Delete and at least one select based on the primary key, that means each table will have 4 procedures. Now take a decent size database of 400 tables, and you have 1600 procedures! And that's assuming you don't have duplicates which you probably will.
This is where using an ORM or some other method to auto generate your basic CRUD operations has a ton of merit.
Comment: Yea that's one possible approach. We use ORMs for everything but reports
Comment: You mean Stored Procedure to read data and `ORM` like `Entity Framework` to do `CRUD` operations ?
Answer: A stored procedure is a set of precompiled SQL statements that are used to perform a special task.
Example: If I have an Employee table
Employee ID  Name       Age  Mobile
---------------------------------------
001          Sidheswar  25   9938885469
002          Pritish    32   9178542436

First I am retrieving the Employee table:
Create Procedure Employee details
As
Begin
    Select * from Employee
End

To run the procedure on SQL Server:
Execute   Employee details

--- (Employee details is a user defined name, give a name as you want)

Then second, I am inserting the value into the Employee Table
Create Procedure employee_insert
    (@EmployeeID int, @Name Varchar(30), @Age int, @Mobile int)
As
Begin
    Insert Into Employee
    Values (@EmployeeID, @Name, @Age, @Mobile)
End

To run the parametrized procedure on SQL Server:
Execute employee_insert 003,'xyz',27,1234567890

  --(Parameter size must be same as declared column size)

Example: @Name Varchar(30)
In the Employee table the Name column's size must be varchar(30).
Answer: A stored procedure is a group of SQL statements that has been created and stored in the database. A stored procedure will accept input parameters so that a single procedure can be used over the network by several clients using different input data. A stored procedures will reduce network traffic and increase the performance. If we modify a stored procedure all the clients will get the updated stored procedure.
Sample of creating a stored procedure
CREATE PROCEDURE test_display
AS
    SELECT FirstName, LastName
    FROM tb_test;

EXEC test_display;

Advantages of using stored procedures

A stored procedure allows modular programming.
You can create the procedure once, store it in the database, and call it any number of times in your program.
A stored procedure allows faster execution.
If the operation requires a large amount of SQL code that is performed repetitively, stored procedures can be faster. They are parsed and optimized when they are first executed, and a compiled version of the stored procedure remains in a memory cache for later use. This means the stored procedure does not need to be reparsed and reoptimized with each use, resulting in much faster execution times.
A stored procedure can reduce network traffic.
An operation requiring hundreds of lines of Transact-SQL code can be performed through a single statement that executes the code in a procedure, rather than by sending hundreds of lines of code over the network.
Stored procedures provide better security to your data
Users can be granted permission to execute a stored procedure even if they do not have permission to execute the procedure's statements directly.
In SQL Server we have different types of stored procedures:

System stored procedures
User-defined stored procedures
Extended stored Procedures

System-stored procedures are stored in the master database and these start with a sp_ prefix. These procedures can be used to perform a variety of tasks to support SQL Server functions for external application calls in the system tables
Example: sp_helptext [StoredProcedure_Name]
User-defined stored procedures are usually stored in a user database and are typically designed to complete the tasks in the user database. While coding these procedures don't use the sp_ prefix because if we use the sp_ prefix first, it will check the master database, and then it comes to user defined database.
Extended stored procedures are the procedures that call functions from DLL files. Nowadays, extended stored procedures are deprecated for the reason it would be better to avoid using extended stored procedures.
Answer: Generally, a stored procedure is a "SQL Function."  They have:
-- a name
CREATE PROCEDURE spGetPerson
-- parameters
CREATE PROCEDURE spGetPerson(@PersonID int)
-- a body
CREATE PROCEDURE spGetPerson(@PersonID int)
AS
SELECT FirstName, LastName ....
FROM People
WHERE PersonID = @PersonID

This is a T-SQL focused example. Stored procedures can execute most SQL statements, return scalar and table-based values, and are considered to be more secure because they prevent SQL injection attacks.
Answer: Think of a situation like this,

You have a database with data.
There are a number of different applications needed to access that central database, and in the future some new applications too.
If you are going to insert the inline database queries to access the central database, inside each application's code individually, then probably you have to duplicate the same query again and again inside different applications' code.
In that kind of a situation, you can use stored procedures (SPs). With stored procedures, you are writing number of common queries (procedures) and store them with the central database.
Now the duplication of work will never happen as before and the data access and the maintenance will be done centrally.

NOTE:

In the above situation, you may wonder "Why cannot we introduce a central data access server to interact with all the applications? Yes. That will be a possible alternative. But,
The main advantage with SPs over that approach is, unlike your data-access-code with inline queries, SPs are pre-compiled statements, so they will execute faster. And communication costs (over networks) will be at a minimum.
Opposite to that, SPs will add some more load to the database server. If that would be a concern according to the situation, a centralized data access server with inline queries will be a better choice.
Answer: A stored procedure is mainly used to perform certain tasks on a database. For example

Get database result sets from some business logic on data.
Execute multiple database operations in a single call.
Used to migrate data from one table to another table.
Can be called for other programming languages, like Java.
Answer: A stored procedure is nothing but a group of SQL statements compiled into a single execution plan.

Create once time and call it n number of times
It reduces the network traffic

Example: creating a stored procedure
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE PROCEDURE GetEmployee
      @EmployeeID int = 0
AS
BEGIN
      SET NOCOUNT ON;

      SELECT FirstName, LastName, BirthDate, City, Country
      FROM Employees
      WHERE EmployeeID = @EmployeeID
END
GO

Alter or modify a stored procedure:
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO

ALTER PROCEDURE GetEmployee
      @EmployeeID int = 0
AS
BEGIN
    SET NOCOUNT ON;

    SELECT FirstName, LastName, BirthDate, City, Country
    FROM Employees
    WHERE EmployeeID = @EmployeeID
END
GO

Drop or delete a stored procedure:
DROP PROCEDURE GetEmployee

Answer: A stored procedure is used to retrieve data, modify data, and delete data in database table. You don't need to write a whole SQL command each time you want to insert, update or delete data in an SQL database.
Answer:
A stored procedure is a precompiled set of one or more SQL statements which perform some specific task.
A stored procedure should be executed stand alone using EXEC
A stored procedure can return multiple parameters
A stored procedure can be used to implement transact
Answer: "What is a stored procedure" is already answered in other posts here. What I will post is one less known way of using stored procedure. It is grouping stored procedures or numbering stored procedures.
Syntax Reference

; number as per this

An optional integer that is used to group procedures of the same name. These grouped procedures can be dropped together by using one DROP PROCEDURE statement

Example
CREATE Procedure FirstTest
(
    @InputA INT
)
AS
BEGIN
    SELECT 'A' + CONVERT(VARCHAR(10),@InputA)
END
GO

CREATE Procedure FirstTest;2
(
    @InputA INT,
    @InputB INT
)
AS
BEGIN
    SELECT 'A' + CONVERT(VARCHAR(10),@InputA)+ CONVERT(VARCHAR(10),@InputB)
END
GO

Use
exec FirstTest 10
exec FirstTest;2 20,30

Result

Another Attempt
CREATE Procedure SecondTest;2
(
     @InputA INT,
    @InputB INT
)
AS
BEGIN
    SELECT 'A' + CONVERT(VARCHAR(10),@InputA)+ CONVERT(VARCHAR(10),@InputB)
END
GO

Result

Msg 2730, Level 11, State 1, Procedure SecondTest, Line 1 [Batch Start Line 3]
  Cannot create procedure 'SecondTest' with a group number of 2 because a procedure with the same name and a group number of 1 does not currently exist in the database.
  Must execute CREATE PROCEDURE 'SecondTest';1 first.

References:

CREATE PROCEDURE with the syntax for number
Numbered Stored Procedures in SQL Server - techie-friendly.blogspot.com
Grouping Stored Procedures - sqlmag

CAUTION

After you group the procedures, you can't drop them individually.
This feature may be removed in a future version of Microsoft SQL Server.
Answer: For a simple explanation, stored procedures are stored programs, a program/function stored into the database.
Each stored program contains a body that consists of an SQL statement. This statement may be a compound statement made up of several statements separated by semicolon (;) characters.
CREATE PROCEDURE dorepeat(p1 INT)
BEGIN
  SET @x = 0;
  REPEAT SET @x = @x + 1; UNTIL @x > p1 END REPEAT;
END;

Comment: "Stored programs" may only increase the confusion.
Answer: A stored procedure is a named collection of SQL statements and procedural logic i.e, compiled, verified and stored in the server database. A stored procedure is typically treated like other database objects and controlled through server security mechanism.
Answer: In a DBMS, a stored procedure is a set of SQL statements with an assigned name that's stored in the database in compiled form so that it can be shared by a number of programs.
The use of a stored procedure can be helpful in

Providing a controlled access to data (end users can only enter or change data, but can't write procedures)
Ensuring data integrity (data would be entered in a consistent manner) and
Improves productivity (the statements of a stored procedure need to be written only once)
Answer: Stored procedures in SQL Server can accept input parameters and return multiple values of output parameters; in SQL Server, stored procedures program statements to perform operations in the database and return a status value to a calling procedure or batch.
The benefits of using stored procedures in SQL Server

They allow modular programming.
They allow faster execution.
They can reduce network traffic.
They can be used as a security mechanism.

Here is an example of a stored procedure that takes a parameter, executes a query and return a result.  Specifically, the stored procedure accepts the BusinessEntityID as a parameter and uses this to match the primary key of the HumanResources.Employee table to return the requested employee.
> create procedure HumanResources.uspFindEmployee    `*<<<---Store procedure name`*
@businessEntityID                                     `<<<----parameter`
as
begin
SET NOCOUNT ON;
Select businessEntityId,              <<<----select statement to return one employee row
NationalIdNumber,
LoginID,
JobTitle,
HireData,
From HumanResources.Employee
where businessEntityId =@businessEntityId     <<<---parameter used as criteria
end

I learned this from essential.com...it is very useful.
Comment: This was either plagiarised at [www.tecZhtarZget.com](https://www.tecZhtarZget.com/seaZrchZoracle/definitZion/stored-procedZZure) (last time stamp in 2019) or this answer was plagiarised from `www.tecZhtarZget.com` (remove all the "Z"s to get to the real domain and URL). Who is plagiarising whom? Or is there a common source?
Comment: The exact phrase *"Stored procedures in SQL Server can accept input parameters and return multiple values of output parameters; in SQL Server, stored procedures program statements to perform operations in the database and return a status value to a calling procedure or batch."* is common for them.
Comment: The source for the `www.tecZhtarZget.com` article has `"datePublished":"2019-04-08T00:00Z"`, so [Adam Hughes](https://www.techtarget.com/contributor/Adam-Hughes) is the likely plagiariser.
Answer: Stored Procedure will help you to make code in server.You can pass parameters and find output.
create procedure_name (para1 int,para2 decimal)
as
select * from TableName

Answer: In stored procedures, statements are written only once and reduces network traffic between clients and servers.
We can also avoid SQL injection attacks.

In case if you are using a third-party program in your application for processing payments, here the database should only expose the information it needed and activity that this third party has been authorized to access. By this, we can achieve data confidentiality by setting permissions using stored procedures.
The updating of the table should only done to the table it is targeting, but it shouldn't update any other table, by which we can achieve data integrity using transaction processing and error handling.
If you want to return one or more items with a data type then it is better to use an output parameter.
In stored procedures, we use an output parameter for anything that needs to be returned. If you want to return only one item with only an integer data type then better use a return value. Actually, the return value is only to inform success or failure of the stored procedure.
Answer: Preface: In 1992 the SQL92 standard was created and was popularised by the Firebase DB. This standard introduced the 'Stored Procedure'.
**
Passthrough Query: A string (normally concatenated programatically) that evaluates to a syntactically correct SQL statement, normally generated at the server tier (in languages such as PHP, Python, PERL etc). These statements are then passed onto the database.
**
**
Trigger: a piece of code designed to fire in response to a database event (typically a DML event) often used for enforcing data integrity.
**
The best way to explain what a stored procedure is, is to explain the legacy way of executing DB logic (ie not using a Stored Procedure).
The legacy way of creating systems was to use a 'Passthrough Query' and possibly have triggers in the DB.
Pretty much anyone who doesn't use Stored Procedures uses a thing call a 'Passthrough Query'
With the modern convention of Stored Procedures, triggers became legacy along with 'Passthrough Queries'.
The advantages of stored procedures are:

They can be cached as the physical text of the Stored Procedure
never changes.
They have built in mechanisms against malicious SQL
injection.
Only the parameters need be checked for malicious SQL
injection saving a lot of processor overhead.
Most modern database
engines actually compile Stored Procedures.
They increase the
degree of abstraction between tiers.
They occur in the same
process as the database allowing for greater optimisation and
throughput.
The entire workflow of the back end can be tested
without client side code. (for example the Execute command in
Transact SQL or the CALL command in MySQL).
They can be used to
enhance security because they can be leveraged to disallow the
database to be accessed in a way that is inconsistent with how the
system is designed to work. This is done through the database user
permission mechanism. For example you can give users privileges only
to EXECUTE Stored Procedures rather that SELECT, UPDATE etc
privileges.
No need for the DML layer associated with triggers. **
Using so much as one trigger, opens up a  DML layer which is very
processor intensive **

In summary when creating a new SQL database system there is no good excuse to use Passthrough Queries.
It is also noteworthy to mention that it is perfectly safe to use Stored Procedures in legacy systems that already uses triggers or Passthrough Queries; meaning that migration from legacy to Stored Procedures is very easy and such migration need not take a system down for long if at all.
Comment: Re *"In 1992 the SQL92 standard was created and was popularised by the Firebase DB"*: There is another '[Firebase](https://stackoverflow.com/tags/firebase/info)' thing nowadays. Can you add one or more ***sources*** for it and ***disambiguate***, please? (But *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***[without](https://meta.stackexchange.com/a/131011)*** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** "Edit:", "Update:", or similar - the answer should appear as if it was written today)
Answer: create procedure <owner>.<procedure name><param> <datatype>
As

A stored procedure consists groups of SQL statements that centralize data access in one point. It is useful for performing multiple operations in one shot.

What is a stored procedure?


What's the best way to remotely access an iPad mini?

Question: This summer I purchased an iPad mini for my Grandmother. I would like to be able to somehow connect to the iPad to do things like update software, apps, and walk her through questions she may have. Does anyone have any suggestions on the best way to do this? She does have her own Apple ID.
Answer: Without a jailbreak : Not possible.
For the software update, since iOS 7 there done automatically by the system when connected to a wifi network.


Can Hawking Radiation occur at the Big Bang singularity or at the Big Crunch singularity?

Question: While reading about Hawking Radiation which occurs due to quantum effects (quantum fluctuations) at the event horizon of a black hole, I was thinking whether this radiation can take place at the Big Bang singularity or at the Big Crunch singularity (if it exists). If it really happens, how does it affect the process of Big Bang (or Big Crunch)? Does the singularity disappear? Is this radiation the main cause of a Big Bang that gives birth to another universe?
Comment: I don't think the "Big Crunch" is (currently) considered to be much of a possiblity, at least per the currently-unchallenged Wikipedia item by that name:  The question seems to be, "Is the expansion of the universe accelerating rapidly, or is it accelerating very rapidly?".  However, I believe the report by the Nobel Committee on Penrose's 2020 award does mention him as feeling that some information's lost in the singularities of black holes, contrary to the expectations of "unitarity" that are held by many people involved in quantum cosmology.
Answer: The first reported observation of Hawking radiation was in the form of "Hawking points" ("circular spots of significantly raised temperature") in the Cosmic Microwave Background radiation, that were described by An, Meissner, Nurowski, and Penrose in the 2020 paper titled "Apparent evidence for Hawking Points in the CMB Sky", whose preprint's freely visible at  https://arxiv.org/abs/1808.01740.pdf (which was, itself, a response to criticism of an earlier paper on the same subject), and appeared several months before Penrose's receipt of a 2020 Nobel Prize in physics.  Those "points" have been considered to represent Hawking radiation from evaporation of supermassive black holes, that differ from the more common black holes which have resulted from the collapse of large rotating stars.  (The supermassive variety result from collapse of a much larger region of "dust", and I believe only one has been observed to occur, in the constellation Sagitarrius, whose observation occurred several years ago [earth time].)
Although the mathematical physicist Penrose has, in collaboration with the late Stephen Hawking, written a number of "singularity theorems", I don't believe he would regard the "Hawking points" as indicative of any origin of the universe in a "Big Bang singularity", as his own cosmological model ("Conformal Cyclic Cosmology", described in his 2010 pop.-sci. book titled "Cycles of Time") is entirely compatible with a universe eternal to the past as well as to the future.
Its complete eternality is described by the Rutgers philosopher David Lindford, in a paper titled "Big Bounce or Double Bang?", whose preprint is freely visible at
https://arxiv.org/abs/1808.01740.abs .  (Physicists might object to analysis of a mathematical physicist's work by a philosopher, but, as Lindford was involved in an analysis of the well-publicized debate between the physicist Sean Carroll and some theologians, I think his profession was entirely appropriate for that role:  Moreover, he provides a great verbal explanation of how thermodynamic entropy plays a role counterbalancing gravitational entropy, in Penrose's model.)
In CCC, all matter eventually decays into radiation. Readers as naive as I once was might confuse this decay with the mass-to-energy conversion that destroyed Hiroshima in a matter of seconds, but, as the decay described by Penrose would take place over time periods that he describes as "aeons", it would actually be more like sequential changes into particles less and less massive, and eventually into bosons (which can pass through each other).  The total lack of mass adequate for the natural formation or artificial construction of any sort of time-keeping mechanism would leave the duration of the aeons undefined, although processes perhaps as simple as the absorption of solar energy by plants (in their production of sugar) would eventually  restore a world perhaps much like our own, but on an almost unimaginably larger scale, as the thermodynamic equilibrium of one aeon would serve as "the" Big Bang of the next.  Quantum processes would assure some differences between each aeon and the next, and, although the doesn't specify this possibility, the many bosons already present in out own aeon might perhaps remain extant as part of some unobservable "potential", like that represented by our own "virtual particles".
Penrose provided one tiny last-minute alteration to his model 26 minutes into his acceptance speech for the Nobel prize:  Some few fermions would survive from each aeon into the next, I'd guess to serve as role models for its eventually colossal amounts of mass.
Comment: "but on an almost unimaginably larger scale" Penrose talks about the Universe forgetting what size it is, and invokes conformal mappings to justify shrinking it to a small size again. I've never understood the point of that in an already infinite universe. It's not hard to imagine the infinities simply getting progressively larger from one aeon to the next, as the quote from your answer seems to imply.
Comment: The philosophical paper I've mentioned was actually written by the Rutgers philosopher Daniel (not David) Linford (not Lindford), but at least I got the paper's name ("Big Bounce or Double Bang?") right.
Comment: Penrose is not a fan of the "multiverse" idea, which arose from inflationary cosmology, whose low-entropy origin he finds very implausible:  I believe he would consider the sequences of time having both radiation and rest mass as temporal "iterations" of a single and unique universe:  They might be described as "temporally local" universes, but, except in relation to other models (discussed by Linford) that are both past- and future-eternal, that terminology would be open to an unnecessary confusion of space and time, whose roles in relativistic coordinate systems do differ from each other.
Comment: To me, the most interesting thing about Linford's paper is that it also describes a different past- and future-eternal model, Nikodem Poplawski's "Cosmology with torsion" (described in numerous papers Poplawski's written between 2010 & 2021, whose preprints can be found by his name on the Arxiv website), that seems to imply local universes on sequentially smaller scales, each formed within a black hole and, consequently, causally separated from the others:  It's almost as though he and Penrose were each describing the same universe or multiverse, as if seen from opposite temporal perspectives.


Scrolling the map in a 2D a tiled game

Question: I am making a small game where I store information about the world around the player (like tiles) using a small 2d array of integers. In the game you can scroll the screen to the left or right. I also want to be able to read portions of the world from a file instead of loading the entire world at once for performance reasons. My concept of doing this is when the camera has scrolled a certain amount, shift the array by a certain amount and replace the old array data with new information from the file. I'm not sure if this makes sense performance wise or if there is a more performance friendly way of doing this so I was wondering if anybody could provide some insight. I drew an image to show what I am talking about.
Comment: You can avoid the copying/moving using a "Clipmap" strategy, where you just overwrite the column that has scrolled off screen with the column that has scrolled on screen, and the rest of the data stays where it is. What moves is your access window for looking up into the array — you van use modular arithmetic so that it wraps around the physical array to still read the tiles as though they were laid out the way you expect to see them on screen. [I show a little of this technique in this answer](https://gamedev.stackexchange.com/a/177398/39518) (you can ignore the hashing parts).
Answer: That looks like how I'd do it. If possible, use an array or array-like data structure that lets you add and remove elements.
Pseudo-code:
<code>//O(1) or O(n) depending on data structure
public void ScrollRight(var newColumn) {
    //remove leftmost column. this will shift other columns left one
    columns.RemoveAt(0);
    //insert new column in the rightmost position
    columns.Add(newColumn);
}
//O(1) or O(n) depending on data structure
public void ScrollLeft(var newColumn) {
    //remove rightmost column.
    columns.RemoveAt(columns.Count - 1);
    //insert new column in the leftmost position, shifting other columns right one
    columns.Insert(newColumn, 0);
}
</code>
The above is much more efficient than this approach:
<code>//DON'T do it this way if you can avoid it
//O(n x m), where n = # of columns and m = # of rows
public void ScrollRight(var newColumn) {
    //shift each column left by copying its data to the previous column
    for (int c = 0; c < columns.Count - 1; c++) {
        var column = columns[c];
        var nextColumn = columns[c + 1]
        for (int r = 0; r < column.Count; r++) {
            column[r] = nextColumn[r];
        }
    }
    //copy new data into the last column, replacing old data
    var lastColumn = columns[columns.Count - 1];
    for (int r = 0; r < column.Count; r++) {
        lastColumn[r] = newColumn[r];
    }
}
</code>

Scrolling the map in a 2D a tiled game


exponential equation with different bases

Question: We have $3^x-5^\frac{x}{2}=4$  My question is what we can do here ? Can we solved it algebraically or we need to notice that $x=2$ and then show that for $x \neq 2$ there aren't any other solutions?
Comment: There are exceptions, of course, but in general the situation is as you describe. One has to use inspection, or a numerical approximation method, to find a root, and show that there are no others. I am more or less sure that this is the case here.
Comment: Is $x$ an integer value or a real value?
Comment: $x$ is a real value
Answer: The given equation holds for the roots of the function
$$f(x) = 3^x-\sqrt{5}^x-4$$
The derivate is
$$f '(x)=3^xln{3}-\sqrt{5}^xln{(\sqrt{5}})$$
So, f '(x) > 0 for all x > 0.
So, f(x) has at most one root.
This root can only be calculated with numerical methods, but in this case,
it is easy to guess the solution.
Answer: Your second approach, viz. showing there are no other solutions would also require some algebra.  With $2t = x$, you can write the equation as
$$(4+5)^t = 4 + 5^t$$
This is obvious for $t=1$ i.e $x=2$.
For $t > 1$, we have  $(4+5)^t > 4^t+5^t > 4+5^t$
for $0 < t < 1$, let $y = \frac1t > 1$, then $(4+5^t)^y > 4^y+5 > 4+5 = \left((4+5)^t\right)^y$
and for $t \le 0$, $(4+5)^t \le 1 < 4 < 4+5^t $
Comment: I can't see only why $(4+5)^t=4+5^t$, I come to $3^{2t}=4+5^t$
Comment: You have $3^{2t}=9^t$.
Comment: right, thanks a lot I see now
Answer: To go one step further, let me consider the equation $3^x-5^\frac{x}{2}=a$ where $a$ is a positive constant.
What Peter showed is that, since the derivative is almays positive, the equation has only one root. In tour case, the problem was simple since, for $a=4$, there is an obvious solution at $x=2$.
Where the problem starts to be different is when there is not obvious solution; except using inspection to try to find two values of $x$ which bracket the solution, the only other solution is to plot the fuction for the same goal. This wille give you a rough estimate I shall write $x_\text{old}$; this value will be the starting point of a root-finder method. Here, for simplicity, I shall use Newton method.
So, for an example, let me chose $a=12345.6789$. Plotting the function shows that the solution is somwhere between $8$ and $9$. So, being lazy, I shall start the iterations at $x_\text{old} = 8$.
As you know, Newton iteration scheme write
$x_\text{new} = x_\text{old} - f(x_\text{old}) / f'(x_\text{old})$
and, after each iteration, $x_\text{old}$ is updated by $x_\text{new}$.
So, for the case I selected, the following iterates will appear : $8.00000$, $8.95595$,  $8.69676$, $8.65122$, $8.65003$ and this is the end of the process for six significant figures. For sure, you can continue iterating until you reach the desired level of accuracy.


Is it necessary to read all the rules in Stack Overflow?

Question: I started using Stack Overflow not so long ago and I'm a little lazy to read all the rules. Will it make my life and other users' lives better if I read that stuff?
Comment: Yes. They are there for a reason...
Comment: I suggest that you *do* take the [tour] as you haven't; that gives you a good introduction. As for the rest, if you are linked to a specific [help] article (perhaps when you ask a question, or it's closed), or FAQ then I would suggest reading them at the latest then; people link you to them for good reason as *normally* your question is lacking the quality or focus for the site and people are directing you on how to make it meet the guidelines.
Comment: The idea that one should read and study the whole Help Center before you interact in any way with the site is unrealistic and not productive. In my experience, it's generally enough to read the relevant rules, articles and guidance as you go along and as soon as you encounter "friction points" where reality defies your expectations.
Comment: I'd also at a minimum recommend you read https://stackoverflow.com/help/dont-ask
Comment: This is one of those questions where if have to ask it, then the answer is "yes".
Comment: I wouldn't really say that the question answers what the OP is asking here, @gnat . That answers how much effort the OP should put in to solving their own problem before asking a question, not how much effort they should put into reading the [help] before using the site.
Comment: Guessing the situation, you might at least need to read [this particular article from the help center](https://stackoverflow.com/help/question-bans).
Comment: i believe alomst nobody has read them. so be like you are around nice people and do like the romans do
Comment: "Is it necessary to read all the rules in Stack Overflow?" If it was necessary then you would need to submit a notarized signature before creating an account. Yes, they exist. Yes, it would be wise to read them. No, your success isn't guaranteed by reading them. I participated on this site for years before ever looking at the rules. The only reason I read them is because I made my way over to meta where discussions about how new users are ruining the site are prevalent.
Comment: Always read the rules or your question will be closed or nobody will answer it .
Answer:
I'm a little lazy to read all the rules.

We have two features to counter your laziness: Closing and Downvoting.

Will it make my life and other users' lives better if I read that stuff?

It depends. By not reading all that stuff, you keep room in your brain for enjoying Cat videos. If you hoped for participating on these sites for more than 6 to 8 weeks, you better spend time familiarizing yourself with what is expected when building a canonical knowledgebase for generations of developers to come.
We're happy to use our close votes and downvotes on lazy content. Do accept that this might bring you closer to a quality ban which basically locks you out from posting questions or answers when you want.
I suggest going over the help articles (notice the pinned topics if you're in a hurry) as well as our faq or even the FAQ on the uber-meta. Also, take the tour.
Do study the tags https://meta.stackoverflow.com/tags and their tag wikis.
I admit Stack Overflow with its Q/A model is different from regular forums. Our sites are strictly moderated for quality. That comes at the price that onboarding / getting started has a bit of a steep learning curve.
Not everything goes here (outsiders like to call that toxic but you better not make that association in front of us). We're sorry for that and we do everything we can to provide info and guidance up-front, while you're asking a question and once you posted content.
Ultimately, there is Meta where we're happy to help in coaching / guiding on the effective use of the site and get the best help from the community. That asks for time investment from all parties involved. With an open mind and eagerness to learn, there is a lot on offer.
I've started with my part (as did others in the comments). Now it is your turn.
Happy to help.