Ubuntu 20.04 desktop files and icons missing

Question: I upgraded from Ubuntu 18.04 to 20.04 but desktop files and icons are missing, How do I should solve this problem?
Comment: OK, you will then need to install the Desktop Icons extension yourself: "sudo apt install gnome-shell-extension-desktop-icons", and then activate the extension in Gnome Tweaks (or the new "Extensions" app).
Comment: if i remember well, desktop folder is handled in a different manner since 19.04 - if this is the only issue you are facing, good to you, in other case i would go for a fresh install of Focal.
Comment: Indeed, an upgrade may be hit and miss. Check whether the gnome shell extension Desktop Icons is installed and active, which is the case in a fresh install.
Comment: @vanadium I checked for Desktop Icons extension, which wasn't active and even installed. I did try to install it but couldn't.
Answer: This worked for me:

Install gnome-shell-extension-desktop-icons:

sudo apt install gnome-shell-extension-desktop-icons

Log  out of Gnome.
Log back in.
Comment: You don't need to log out. Simple ALT-F2 R will do the job aswell.
Comment: just restarting worked for me, but it's ALT-F2 r (lower case r)
Comment: For Ubuntu 22.04, it's `sudo apt install gnome-shell-extension-desktop-icons-ng`
Comment: Yeah, It worked but there are a bunch of other problem/bugs. I can't open or remove a file on desktop using keyboard, do you have the same problem?
Comment: This worked!! Thanks.
Answer: The problem might be that the installation did not go according to plans, not to worry though! The simplest (and most effective) operation you can do is:
sudo apt dist-upgrade

This will automatically install / update / repair all the needed packages for your current version.
Comment: worked perfectly.
Comment: The accepted answer does not for me. After `sudo apt install gnome-shell-extension-desktop-icons`, I cannot gui login ubuntu again :( Since I missed lots of packages, gnome-shell-extension-desktop-icons just one of them. But `sudo apt dist-upgrade` works perfect for me.
Comment: By far should be the accepted answer!
Answer: I'm on stock Ubuntu 20.04.2, fresh install.
I also noted out of the blue, that the contents of ~/Desktop failed to show up on the desktop.
So I went ahead and enabled the Desktop Icons extension in Tweaks, and nothing happened. After I have restarted the Gnome Shell with Alt+F2 + r, and still no icons, I went back to Tweaks only to find the Desktop Icons extension disabled again. So I repeated the cycle, this time tweaking on the extension's preferences, hoping that it would unstuck the glitch somehow. No luck, the Desktop Icons extension kept disabling itself on each restart of Gnome Shell.
Then I looked in dconf-editor, in org.gnome.shell enabled-extensions: "desktop-icons@csoriano" was in there, as it was supposed to be. Yet the problem persisted.
Then:
I do have an additional piece of GUI window, that is called, plainly, Extensions in the apps / activies overview. It's a single window, and looks very similar to Gnome Tweaks' "Extensions" tab UI. Only, this one takes precedence over the one in Tweaks.
I don't know where this Extensions app originates from: whether it's installed on 20.04 by default, or maybe I have obtained it by installing the gnome-shell-extensions package.
Anyways, enabling Desktop Icons in the plain Extensions app solved everything.
Comment: The only solution among those proposed above that worked for me. Thanks! I would never have thought that a second "Extension" GUI existed. No idea where it came from...
Comment: Similar to your solution, but for me worked enabling "Extensions" itself, in the same GUI
Comment: @PhilippeP you are on a lucky streak today: https://askubuntu.com/q/1329463/1157519 :D
Answer: I have Ubuntu 20.04 (Gnome) and sometimes icons are missing after restart. I use a rather silly solution. I just create a new file, this causes the gnome to load the desktop icons again. ctrl+alt+t to open a terminal, then:
touch Desktop/NEW #Creates an empty file named NEW
rm Desktop/NEW #Deletes the file

Answer: Try switching desktop manager.
I also just upgraded my stable 18.04 to 20.04. Initially I can't even see my initial login prompt and I have forgotten that I installed lightdm and made that the default vice gdm (gnome desktop manager) which is version 3 now (gdm3).
I followed this nice how-to:
Switch Display Manager in Ubuntu 20.04
You can have both gdm3 and lightdm installed but one can only be set active.
Good Luck!
Comment: Also, you can always drop to TTY mode from the desktop manager GUI by [Ctrll-Alt-F1 to F4] depending on the run level you need to be. Try run-level 4 first with your sudoer password.
Comment: Return to the desktop manager GUI with [Ctrl-Alt-F7] from the TTY
Answer: I tried sudo apt install gnome-shell-extension-desktop-icons but it did not work for me because my gnome shell was fully updated, but I just right clicked on the desktop and created a folder then just like that all my icons appeared; hope this helps out.
Answer: Open application "Tweaks" and go to Extentions tab.
If you do not have one simply install it:
sudo add-apt-repository ppa:tualatrix/ppa
sudo apt-get update
sudo apt-get install ubuntu-tweak

Turn on the Desktop icons checkbox.

Works immediatelly (no restart is needed).
For me it only worked.


What are all the various ways to create polyhedra out of regular polygons?

Question: So I've started reading the book 'Measurement' by Paul Lockhart but have been stuck on this question for a while now. The question is "What are all the symmetrical polyhedra?". The author asks you to find a pattern related to adding up shapes and their angles around a sphere (e.g a triangle being 1/6th of a full turn, a square 1/4 and so on) so that the sum of the angles adds up to less than one full turn to prevent an intersection when the corners are folded up. I hope I've explained this enough, any help would be much appreciated!
Answer: What do you mean by "symmetrical"?
If you mean regular polyhedra, then this includes a single type of regular polygonal faces as well as a single type of regular polygonal vertex figures. Additionallly asking for convexity and a positive angular defect, thon it is clear that you can have only 3 triangles, 4 triangles, 5 triangles, 3 squares, or 3 pentagons per vertex. This then leads to the 5 Platonic solids. https://en.wikipedia.org/wiki/Platonic_solid
You might want to release the convexity constraint, both for the faces and for the vertex figures. This will add the Kepler-Poinsot solids. https://en.wikipedia.org/wiki/Kepler–Poinsot_polyhedron
But when just asking for uniformity of polyhedra (vertex transitivity, any number of regular polygonal faces), then the according set is listed here: https://en.wikipedia.org/wiki/Uniform_polyhedron
If you would be interested in polyhedra with any number of regular polygonal faces and any number of vertex types of any shape, while restricting to convex solids only, then you will Resort for the set of Johnson solids: https://en.wikipedia.org/wiki/Johnson_solid
--- rk


Unable to open Mail in macOS Catalina

Question: On a MacBook Pro running macOS Catalina Version 10.15.5, every time I try to open Mail.app in one of our user's acounts, the application fails to open and I get this error:

Mail quit unexpectedly.
Click Reopen to open the application again. Click Report to see more detailed information and send a report to Apple.

Here's an excerpt from the report:
Process:               Mail [6567]
Path:                  /System/Applications/Mail.app/Contents/MacOS/Mail
Identifier:            com.apple.mail
Version:               13.4 (3608.80.23.2.2)
Build Info:            Mail-3608080023002002~43
Code Type:             X86-64 (Native)
Parent Process:        ??? [1]
Responsible:           Mail [6567]
User ID:               501

Date/Time:             2020-06-07 14:21:25.799 -0500
OS Version:            Mac OS X 10.15.5 (19F101)
Report Version:        12
Bridge OS Version:     4.5 (17P5300)
Anonymous UUID:        8BA95E6B-F4C0-FE35-590C-A4B6D79839C8

Sleep/Wake UUID:       560A8417-0826-4C98-BA6E-B997106BA321

Time Awake Since Boot: 56000 seconds
Time Since Wake:       1700 seconds

System Integrity Protection: enabled

Crashed Thread:        4  -[MFPersistenceVersionUpgrader run]  Dispatch queue: NSOperationQueue 0x7fe445c11cb0 (QOS: UNSPECIFIED)

Exception Type:        EXC_CRASH (SIGABRT)
Exception Codes:       0x0000000000000000, 0x0000000000000000
Exception Note:        EXC_CORPSE_NOTIFY

Application Specific Information:
dyld3 mode
*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'V3->V4 migrator must be run before persistence version can be migrated to V5'
terminating with uncaught exception of type NSException
abort() called

Here's what I've tried so far:

Restarted the computer… repeatedly.
Tried opening Mail.app in the affected user after a Safe Boot.
Reset the PRAM.
Freshly installed macOS.
Confirmed that Mail.app is in the Applications folder and tried to open it directly from there.
Deleted all accounts from System Preferences (can't open Mail, so can't delete from in there).

All of the above has had precisely zero change on the behavior.
I created a new user on the same machine and Mail.app opens just fine on that user, so that would seem to point to an issue specific to this user, but I'm at a loss as to what that might be.
Any idea how to resolve this?
Answer: When I was 99% drafting the question above, I came upon a solution adapted from this post on AppleToolBox.
Here are the steps:

Go to ~/Library/Containers/com.apple.mail/Data/Library/Saved Application State and delete com.apple.mail.savedState.
Go to ~/Library/Containers and drag com.apple.mail and com.apple.MailServiceAgent to your desktop.
Go to ~/Library/Mail/ and drag everything in that folder to your desktop.
Restart.
If it's now working, trash everything on your desktop.

Because I had already tried deleting accounts before finding this solution, I had to re-add all of them to the user, but it otherwise seems to be working normally again.

Unable to open Mail in macOS Catalina


Fifteen minuter? Give it a shot

Question: Exactly one of the seven tiles on the bottom will go in each of the seven curved regions formed by the overlapping circles. Two additional tiles have been placed for you - but the question is which tiles go where and why?
Comment: I think I've got ROT13{HF cerfvqragf (Gehzc, Bonzn, Zbaebr, Ebbfriryg, Erntna)} and ROT13{fhowrpgf bs Jneuby neg (Zbaebr, Ryivf, pnaf, Jneuby)}, but not sure about the third category or the last member of the second one. The second category would also fit with the first half of the title.
Answer: Here's how you can resolve this Venn diagram:

The three ellipses represent:

 Top left: Surnames of US Presidents

  (James) Monroe, (Barack) Obama, (Ronald) Reagan, (Theodore/Franklin) Roosevelt, (Donald) Trump

 Top right: Andy Warhol artwork subjects

 Campbell's Soup Cans

Elvis Presley

 Marilyn Monroe

 Teddy Roosevelt

 Andy Warhol himself!

 Bottom: Shot in failed assassination attempts

Pope John Paul II, Ronald Reagan, Theodore Roosevelt, Andy Warhol

 The name appearing in all 3 categories is thus 'Roosevelt' - what a colourful life!

Re the title:

 Andy Warhol once said that one day everybody would be 'famous for fifteen minutes', and 'shot' suggests gunshots.

Fifteen minuter? Give it a shot


Downloading Ubuntu Live CD

Question: I've looked at the download page and it's not clear to me which download I use to enable me to create an Ubuntu Live CD.
I need the facility to try to recover data from a failing hard drive, using the instructions in this link:
https://www.howtogeek.com/howto/windows-vista/use-ubuntu-live-cd-to-backup-files-from-your-dead-windows-computer/
Many thanks
Comment: https://www.ubuntu.com/download/desktop Any will do ...
Answer: As Ravexina has suggested either of the desktop images will do for creating a live CD. The only difference would be is if you were installing Ubuntu on your hard drive which you are not as you are recovering data from it. You can then burn the image, mount the drive and copy the files onto an external disk following the rest of the instructions in the article.

Downloading Ubuntu Live CD


Install windows 7 through virtual box

Question: I am using Ubuntu 12.04. I want to install Windows 7 on my system from a CD through VirtualBox. I searched the detailed tutorials through google but I did not find one that worked.
So can some one kindly share any detailed tutorial or link which will really help me out.
Comment: Except the Oracle product doesn't install. It downloads and when I click install the install screen disappears and nothing happens.
Answer: Go to their website:
https://www.virtualbox.org/

Then choose linux host

see 12.04 then choose either 32 bit or 64 bit

wait until download finishes

install virtualbox by clicking on the downloaded file
After that launch the program

Click on New and a window will show up
Choose a name and a version

click next
Now choose the amount of Ram. Red is danger. Green is OK

click Next
choose create virtual Drive

click create and a new windows will show up
Choose the 1st option and click next
Now either choose fixed or dynamically. I prefer dynamical so you can change the size later

Click next
Now choose the amount you want to allocate for your harddisk give it a name and click create

Now we need to configure it so Click on settings

Ignore the error and click OK

choose storage on the left panel and choose the CD icon that says Empty

Now Click on the CD icon on the far right and choose DVD/CD and Click OK

Now Click on the Start Button and boot from your CD

Do not forget to insert your CD
Comment: I don't think its necessary to insert the CD. You can click on that green + button on the storage settings and show where the ISO file is.
Comment: Using the `virtualbox` package from the repositories should do the job as well, if you hesitate to download the latest version from their homepage.
Answer: It may be convenient to use virtual machines you download and manage locally from Microsoft:
https://developer.microsoft.com/en-us/microsoft-edge/tools/vms/linux/
Comment: because this are normall VM on which you can install whatever you need without need to buy windows or search some torrents
Comment: "Please note that these virtual machines expire after 90 days. We recommend setting a snapshot when you first install the virtual machine which you can roll back to later." Not normal VM.
Comment: The question is about installing Windows 7. Why would you link to a Virtual-Image  meant to test Edge and IE?
Comment: possibly now moved to: https://developer.microsoft.com/en-us/windows/downloads/virtual-machines/
Answer: There you go:

http://www.intowindows.com/how-to-install-windows-7-on-virtualbox/ (Kinda old, but the process is the same.)
http://www.howtogeek.com/forum/topic/how-to-install-windows-7-in-virtualbox-guide-hatryst (newer one)
http://nachiket.wordpress.com/2009/02/03/how-to-install-windows-7-on-virtualbox/ (kinda old too)
http://www.youtube.com/watch?v=HoSebbqBQQo ( A youtube video. Kinda old too, but still)

Install windows 7 through virtual box


Relative velocity related to acceleration

Question: Let's say we have a car moving on the horizontal ground with a velocity of $10 \hat{i} \frac{m}{s}$. A person inside throws a ball vertically upward with a velocity of $3 \hat{j} \frac{m}{s}$. Now I wanted to know a few things, first of all the initial velocity of the ball as seen by a ground observer would $(10 \hat{i} + 3 \hat{j}) \frac{m}{s}$. Now if the car maintains that uniform velocity, at every moment of the motion of the car, the velocity of the ball in the horizontal direction for the ground obsever would always be $ 10 \hat{i} \frac{m}{s}$ right? And secondly, if the car were to accelerate, then does the velocity of the ball in the horizontal direction also change with that for the ground observer? I personally think it does because the Car and the Ball are a system as a whole and hence the ground person cannot differentiate it, but I am not completely sure about it either.
I would like to basically know if acceleration in the horizontal direction causes the horizontal velocity of the ball thrown in the car (upwards or with an angle, doesn't really matter) to change for a ground observer?
Answer: The car, the person throwing the ball, and the ball --- these three constitute a whole system as long as they are moving together. And when is that? When the person sits on the car and keeps the ball in his hand, the three move together with the same velocity.
Now as soon as the person throws the ball, he no longer has contact with it. Hence, that person and the car can no longer affect the motion of the ball.
Your confusion arises because you think that the ball is a part of the system of the car (and the person). Why? Because it is "inside" the car? Why would being "inside" the boundaries of the structure of the car make you a part of "system"?
Once the person has thrown the ball, the car's acceleration cannot possibly alter the velocity of the ball because there is no force on it.
If you're still confused about the ball being part of the system, think about throwing a ball. Go in an open area, throw a ball high in the air and start running at high speed in some random direction. A friend of yours standing nearby would not observe any change in the motion of the ball except in the vertical direction.
To conclude, ----
to be able to change the velocity of an object, you must apply force on it. One way of applying a force is to keep it in contact with you. Since the nature of the force is complicated, it is simply referred to as being a "system" of all the objects touching each other. As soon as the "touching" is over, it is no longer a part of the system, hence no force, hence no changes in velocity for a ground-based observer.
Comment: Thank you for your answer, it makes sense to me. Although the last part where you tell about self experimentation, I think you meant that I throw the ball while running vertically upwards and then run with a higher velocity which in no way does interfere with the ground observer as they would still see that the ball is having the same horizontal velocity I had before I threw it.
Comment: Are the person and the ball not in contact via the air inside the car, though? If the air inside the car accelerates with the car, would that not accelerate the ball as well, albeit to a lesser extent?
Comment: @JoãoMendes That is an extremely negligible aspect, and I guessed that the question does not ask for such minor factors.
Comment: @RaghavGupta Fair. +1
Answer: If the car is constantly accelerating after throwing the ball up, then the ball will retain the horizontal velocity which it gained at the moment it was thrown up(due to N2L) and if the car accelerates,

the ball will move backwards with respect to the guy in the car,
and for the guy on the ground, the velocity will be the same as it did when the ball was thrown up, and acceleration of the car won't affect his observations regarding the ball

Correct me if I am wrong.
Comment: Yes, it does make sense to me now. The "contact" is what is needed to transfer all such information. Thank you.
Answer: Yes your predictions are absolutely right. The ground observer seeing the ball thrown upwards in a  car would see the velocity of the ball to be moving with $(10 \hat{i} + 3 \hat{j}) \frac{m}{s}$ and a person in the car will be seeing it as $3 \hat{j} \frac{m}{s}$. Yes if the car was moving at uniform velocity, the observer would be still seeing it as $(10 \hat{i} + 3 \hat{j}) \frac{m}{s}$ in the positive x direction. Also the person in viewing it in the ground frame sees the ball as a parabola(projectile) this is because it has a horizontal velocity and vertical velocity and the person in the car frame sees as if the ball is thrown vertically upward ( due to relative motion) If the car had accelerated in the horizontal x direction, it does affect horizontal motion but never affects vertical motion, the horiontal and vertical motion are completely independent. If the ball was thrown horizontally say in the same direction as Car's motion with $5\frac{m}{s}$ and person in ground would see it moving with $(10 \hat{i} + 5 \hat{i}) \frac{m}{s}$, i.e $15\frac{m}{s}$. If thrown at an angle find the respective components in the horizontal and vertical motion.
So while solving problems use the kinematic equations independently in the horizontal and vertical motions and solve for what is being asked for. Aceeleration of the car does not affect velocity of the ball in the horizontal direction. The ball acquires the velocity of the car at the instant it was thrown and after that no matter what was the motion of car, it doesn't affect motion of the ball
Comment: I hope now it's clear. Please let me know if you have any more doubts
Comment: You miss the point of my question, the previous two answers have cleared my doubt.  "If the car had accelerated in the horizontal "x" direction, it does affect horizontal motion but never affects vertical motion" I never really asked about this.


Can I replace treacle with molasses in my fruit cake?

Question: I would like to know if replacing treacle with molasses in my fruit cakes will change the texture of the cake and how much molasses can I use in a 2.5 kg. of baked cake?
Comment: You might want to post your recipe (or a link to it) to get good answers - the substitution might involve changing another ingredient or two.
Comment: It will probably color your fruitcake much darker brown than other options....
Comment: @SAJ14SAJ says, it gives rich brown color and i love that color so i use molasses but if you provide the recipe then it will easy to suggest how much molasses you should use for 2.5 kg. baked cake
Answer: In my experience, any "liquid sugar" (warning: colloquial, not very accurate term) can be substituted well without texture problems. Mollasses, treacle, sugarbeet syrup, liquid glucose, golden syrup, and even agave syrup all seem to work well as substitutes. I suppose corn syrup or sorghum will work well too, but haven't tried them.
You get differences in taste, but in most recipes, the taste of the substitute is a good fit. Most of these tastes rely on caramelization anyway, so you should try to use something of the same darkness because roughly, two "liquid sugars" of the same darkness have the same taste intensity. Using a lighter substitute is mostly OK too, although you will lose a little bit of aroma. Using a dark substitute in a recipe which calls for a light one can result in the taste of the sweetener overwhelming all other tastes. For example, pliable ganache is made by adding liquid glucose to the ganache; I would never use sugar cane syrup as a substitute there.


Adobe Illustrator - create new document at launch

Question: Is it possible to change Adobe Illustrator settings to create an empty new document each time it is launched?
Comment: Could you just replace the shortcut to Illustrator with a shortcut to a black .AI document?
Comment: Every document you create is exactly the same?
Comment: @Scott Yes most are the same size and format.
Comment: @rraallvv fair enough :) I could never get away with that. :)
Answer: On OS X you can use an AppleScript to launch the app then create a new doc based on your settings. I've used this approach extensively, though not to create new docs.
I haven't written AS in a while so I'll leave the complicated stuff to a more qualified person. But I can give you some example solutions.

To launch the app or just activate it:
launch application "Adobe Illustrator"
Direct AS to the file you want to open (like a template) with a path or a prompt like so:
set theDoc to choose file with prompt "Select the document"
Then tell Illy to open the file:
tell application "Adobe Illustrator" to open theDoc

You can also set up some options to present in a prompt when the script is launched.

Choose between opening various common template files without the prompt
Create a new doc with the default settings
Point the applescript to a javascript that steps in once the Finder interaction is over
Activate a specific Workspace, depending on the project you're working on
Synchronize settings with a server or Dropbox directory

Spending a little time setting up the script at the start can result in noticeable cumulative time savings.
Answer: I would save your blank document as an Illustrator Template (.ait) file and open that from Explorer/Finder instead. The new document will be named "Untitled" until you save it, so you can't accidentally save over the template.
The template can contain swatches, empty layers, view settings, your company logo in the corner, etc.
See also Working Smarter, with Templates on the Adobe Illustrator blog.
Comment: However, in OS X there is a bug with the way Adobe implemented templates. If you double click the template file from the finder it immediately duplicates the file in the same directory and opens that copy. I would be very happy to learn that this problem has been solved in new versions of Creative Suite or OS X but I have heard no such reports.


creating index using pca

Question: i want to create an index. it has 3 subindices A,B,C. each subindex further consists of 3 different variables A1,A2,A3,B1,B2,B3 and so on. in total there are 9 variables. i want to assign weights using PCA. my question is do i assign weights to the variables A1,A2,A3 then aggregate to find an overall score for subindex A, repeat the process for subindex B and C and then assign weights to subindex A,B and C, or do i calculate it for all the variables combined together?
Comment: Please clarify your specific problem or provide additional details to highlight exactly what you need. As it's currently written, it's hard to tell exactly what you're asking.
Answer: I think that you could defend either position. In my opinion, it should depend on whether you need to capture as much of the variance of the full set as possible (extract weights from one PCA) or whether you want to maximize coherence of each of the extracted components (you could justify doing individual PCAs).
If you use the PCA scores from the full data set, for each component you will likely have strongly positive scores that will clearly inform each that latent variable, but remember that all variables get scores on each dimension. Some will have scores near zero and will be, effectively, influencing that latent dimension very little. However, you might also get strongly negative scores for some variables on one dimension (that are likely strongly positive on a different dimension). PCA is trying to use the scores/loadings/weights to explain as much variance as possible. Look at the positive and negative loadings ask whether you can make sense of each dimension. If there are very strong negative loadings that make it difficult to explain what that dimension means, you might consider separating them.
If you separate the variables by group and run individual PCAs, you will likely get only positive scores, and each latent variable can only be influenced by that subset. You will get more coherent latent dimensions, but know that you are explaining less (perhaps much less) of the total variance that existed in the full data set.
You might also consider identifying the variable groups with PCA, then using CFA with the subgroups to test for coherence and get your final indices.

creating index using pca


Can I say Interface is a set of general behavior?

Question: I'm new to OOP. Can I say Interface is a set of general behavior that may be have and act uniquely by a set of objects that have in common? And Abstract class has similarity with Interface but it have default method that also can be have and perform by a set of objects? Thanks
Answer: No. Commonly you would say:

An Interface is a contract
An Abstract class is a class which you can't have an instance of
Answer: No, an interface in a strict sense does not have any behaviour at all.
It defines formal rules of interaction.
To be more concrete, it defines the types of inputs (arguments) and outputs (returns) of methods but makes no assertion about how the output values depend on the inputs and what side effects a method call might have.
I like to add thet in Java 8, you have the option to add behaviour in interfaces by defining default methods, that's why I wrote "in a strioct sense" in the beginning.
Answer: "General behavior" isn't what an interface is about.
Understand that interface can mean two different things in OOP.
The intrinsic interface of an object is really just a set of messages you can send it by calling it's methods. There is no behavior defined here.
There is also the explicit interface type that some languages have. This competes with abstract classes but has a slightly different set of rules depending on your language.
With abstract types you can define behavior that can be overridden that you can think of as "general behavior".   You can do this same trick in some versions of some languages with a type that they unfortunately decided to call "interface".
These explicit interfaces were only recently given this ability. They added it because they wanted to not break legacy code when they expanded published interfaces. This let them provide what I prefer to call "default behavior".  It's doubtful they'd have named this type "interface" if they knew that it would eventually allow this.
So no, "general" behavior is much more an abstract class thing. Now with composition, it's very much a "default"  behavior thing. From the outside though it all looks like the same thing.


How are regular expressions processed?

Question: How are regular expressions processed?
Comment: I think you need to be a little bit more specific here, unless you want answers like "the computer does that".
Comment: This needs more context. There are many different techniques.
Answer: Regular expressions can be modeled as a Deterministic Finite State Machine.  That would probably be a good place to start if you wanted to "process" one.
Comment: I think regular expressions are non-deterministic finite state machines  (Jurafsky & Martin, Speach and Lnaguage Processing, 2000, Prentice Hall - Chapter 2)
Comment: @James.  More commonly, yes they are.  The often imitated Perl implementation is non-deterministic.  There are some engines that are deterministic though.  See my answer below.
Answer: A regular expression describes a ruleset for a state machine. It generally moves over a string one character at a time, making decisions based on what happened on previous characters and what is described in the regex.
Any regex can also be written as a loop over a string one character at a time. Some of these could be fairly simple, but the power of regex is found when what appears to be a simple regex, with a few lookbehinds and subgroups would take a thousand lines of code to reproduce in your own state machine.
Answer: This question is very broad. This is not a complete answer but Jeff Moser has an excellent write-up on his blog that walks through .NET's regex process: How .NET Regular Expressions Really Work
I suspect other answers will shed light on other areas of regular expressions unless your question is updated to be more specific.
Answer: This will depend on which regex implementation you're referring to.
There are 2 common but different techniques used in regex engines:

Nondeterministic Finite State Machine
Deterministic Finite State Machine

This MSDN article explains several techniques implemented in various engines and then goes onto explain .NET's implementation and why Microsoft chose what they chose for .NET.
They go even more in-depth in the various articles you see listed here.
Answer: http://www.moserware.com/2009/03/how-net-regular-expressions-really-work.html
Answer: Despite what everyone here says about state machines, you can write a remarkably simple regex recogniser using recursive techiques with very little state. There are examples of these in two of Brian Kernighan's books Software Tools In Pascal and The Practice Of Programming.

How are regular expressions processed?


What are the WordPress alternatives for Ruby on Rails?

Question: What are the WordPress alternatives for Ruby on Rails? How do they compare to WordPress?
Answer: Refinery looks really simple but I don't have an in depth comparison to WordPress.  Looks like it has a lot less features but likely easier to maintain and extend upon.  It's pretty standard to write really crappy code in the WordPress community.
Answer: I've been using WordPress more or less against my will for about two four years now (since I started using other frameworks (I've started to really love WP again)). I think there is no "good Rails alternative". Of course there are a lot of blog engines but none have as many plugins available or are as well known with clients. Let's be honest, WP has a fantastic front-end, clients seem to like that. The reason "we developers" look for Rails alternatives is obviously because Rails developer aren't comfortable with WP. But there's no platform out there that has the same out-of-the-box completeness and user friendliness as WP. For blog-like purposes that is of course.
Comment: Wordpress indeed does come with a lot of out of the box very useful features. However, what do you do on Wordpress when you need to update thousands of posts? In the ruby community there are very powerful tools such as sidekiq (https://github.com/mperham/sidekiq), which allows you to process thousands of background jobs, allowing whatever app one is building to scale. Wordpress does not have a background job processing platform that is any where near the sophistication of sidekiq. Last time I checked I think there was Bernard PHP, but it's underwhelming compared to sidekiq.
Answer: Publify can be a answer, but I'm not able to compare with WordPress.
Answer: You may want to look into Wordscript ; it includes API's written in Ruby and PHP that connects to existing WordPress databases and returns json structures (made from generated SQL).
Useful if you want to keep full administrative features of WordPress, and have a somewhat simple WordPress site. Neither version requires WordPress to be installed locally, but you can't really do anything administrative with the api or comments/custom fields (yet). Also the API is much faster and consumes a fraction of the resources WordPress would.


HtmlAgilityPack.HtmlDocument Cookies

Question: This pertains to cookies set inside a script (maybe inside a script tag).
System.Windows.Forms.HtmlDocument executes those scripts and the cookies set (like document.cookie=etc...) can be retrieved through its Cookies property.
I assume HtmlAgilityPack.HtmlDocument doesn't do this (execution). I wonder if there is an easy way to emulate the System.Windows.Forms.HtmlDocument capabilities (the cookies part).
Anyone?
Comment: using HtmlAgilityPack.HtmlDocument
Answer: When I need to use Cookies and HtmlAgilityPack together, or just create custom requests (for example, set the User-Agent property, etc), here is what I do:

Create a class that encapsulates the request/response. Let's call this class WebQuery
Have a private CookieCollection (in your case public) property inside that class
Create a method inside the class that does manually the request. The signature could be:

...
public HtmlAgilityPack.HtmlDocument GetSource(string url);

What do we need to do inside this method?
Well, using HttpWebRequest and HttpWebResponse, generate the http request manually (there are several examples of how to do this on Internet), create an instance of a HtmlDocument class using the constructor that receives an stream.
What stream do we have to use? Well, the one returned by:
httpResponse.GetResponseStream();

If you use HttpWebRequest to make the query, you can easily set the CookieContainer property of it to the variable you declared before everytime you access a new page, and that way all cookies set by the sites you access will be properly stored in the CookieContainer variable you declared in your WebQuery class, taking in count you're using only one instance of the WebQuery class.
Hope you find useful this explanation. Take in count that using this, you can do whatever you want, no matter if HtmlAgilityPack supports it or not.
Answer: I also worked with Rohit Agarwal's BrowserSession class together with HtmlAgilityPack.
But for me subsequent calls of the "Get-function" didn't work, because every time new cookies have been set.
That's why I added some functions by my own. (My solution is far a way from beeing perfect - it's just a quick and dirty fix) But for me it worked and if you don't want to spent a lot of time in investigating BrowserSession class here is what I did:
The added/modified functions are the following:
class BrowserSession{
   private bool _isPost;
   private HtmlDocument _htmlDoc;
   public CookieContainer cookiePot;   //<- This is the new CookieContainer

 ...

    public string Get2(string url)
    {
        HtmlWeb web = new HtmlWeb();
        web.UseCookies = true;
        web.PreRequest = new HtmlWeb.PreRequestHandler(OnPreRequest2);
        web.PostResponse = new HtmlWeb.PostResponseHandler(OnAfterResponse2);
        HtmlDocument doc = web.Load(url);
        return doc.DocumentNode.InnerHtml;
    }
    public bool OnPreRequest2(HttpWebRequest request)
    {
        request.CookieContainer = cookiePot;
        return true;
    }
    protected void OnAfterResponse2(HttpWebRequest request, HttpWebResponse response)
    {
        //do nothing
    }
    private void SaveCookiesFrom(HttpWebResponse response)
    {
        if ((response.Cookies.Count > 0))
        {
            if (Cookies == null)
            {
                Cookies = new CookieCollection();
            }
            Cookies.Add(response.Cookies);
            cookiePot.Add(Cookies);     //-> add the Cookies to the cookiePot
        }
    }

What it does: It basically saves the cookies from the initial "Post-Response" and adds the same CookieContainer to the request called later. I do not fully understand why it was not working in the initial version because it somehow does the same in the AddCookiesTo-function. (if (Cookies != null && Cookies.Count > 0) request.CookieContainer.Add(Cookies);)
Anyhow, with these added functions it should work fine now.
It can be used like this:
//initial "Login-procedure"
BrowserSession b = new BrowserSession();
b.Get("http://www.blablubb/login.php");
b.FormElements["username"] = "yourusername";
b.FormElements["password"] = "yourpass";
string response = b.Post("http://www.blablubb/login.php");

all subsequent calls should use:
response = b.Get2("http://www.blablubb/secondpageyouwannabrowseto");
response = b.Get2("http://www.blablubb/thirdpageyouwannabrowseto");
...

I hope it helps when you're facing the same problem.
Comment: PS `public CookieContainer cookiePot;` needs to be `public CookieContainer cookiePot = new CookieContainer;`

HtmlAgilityPack.HtmlDocument Cookies


Ignore some files from SVN commit

Question: Have to remove the logs and schema.rb from the svn as that is machine dependent.My schema is not migrating after the update as the schema revision on different machine is of different order.
Answer: I assume you need to ignore file while adding/commiting. To heal the situation first add unneeded files/patterns to svn:ignore keyword.
Then make a backup of these files for yourself and remove them from SVN repository and commit removal. Next, copy your backups back to working copy. These files will not be visible by SVN any longer as you have added them for "ignoring".
Answer: This is done with adding svn:ignore property. CD to where your files are located and try the following command:
svn propset svn:ignore schema.rb .

Note the dot at the end of the command.
Check that the files are ignored:
svn status --no-ignore

Then commit.

Ignore some files from SVN commit


Datasheet View to include overlay data

Question: Is there a way to include the data from the calendar overlays in the datasheet view? I am trying to aggregate the data from the different calendars into a table or datasheet format.
Answer: It doesn't seem possible out of the box, but you can code the data requests you need and the presentation you need. I'll mark this answer community wiki so anyone can improve and add details as needed.

Datasheet View to include overlay data


How did sanatkumars reach Lord Vishnu's abode?

Question: How did sanatkumars reach Lord Vishnu's abode? Sanatkumars were also incarnation of Vishnu, but they were only children, how did they reach there in such a small age? This is a difficult task. What technology they used?
Answer: You are asking how Sanat-Kumaras reached the abode of Lord vishu – what technology they used?
The answer is given in Shreemad Bhagvat Purana Skandha 3 Chapter 15
These verses tell us how Sanat-Kumaras used to travel in celestial regions

ब्राह्मो उवाच मानसा मे सुता युष्मत्पुर्वजा: सनकादय : |
  चेरुर्विहायसा लोकानलोकेषु विगतस्पृहा: ||१२||
mānasā me sutā yuṣmat- pūrvajāḥ sanakādayaḥ  cerur vihāyasā
  lokāl lokeṣu vigata-spṛhāḥ
Lord Brahmā said: My four sons Sanaka, Sanātana, Sanandana and
  Sanat-kumāra, who were born from my mind, are your predecessors.
  Sometimes they travel throughout the material and spiritual skies
  without any definite desire.SB 3.15.12

This verse tells us that they used to travel  throughout the material and spiritual skies. The Gita Press version tells us that they were traveling through Skyway (Akash-Marga).
Now look at this verse

तद्विव्श्रगूर्वधिकृतं भुवनैकवन्धं |
    दिव्यं विचित्रविबुधाग्र्यविमानशोचि: |
    आपु: परां मुदमपूर्वमुपेत्य योग |
    मायाबलेन मुनयस्तदथो विकुन्ठम् ||२६||
tad viśva-gurv-adhikṛtaṁ bhuvanaika-vandyaṁ
    divyaṁ vicitra-vibudhāgrya-vimāna-śociḥ
    āpuḥ parāṁ mudam apūrvam upetya yoga-
    māyā-balena munayas tad atho vikuṇṭham
Thus the great sages Sanaka, Sanātana, Sanandana and Sanat-kumāra,
  upon reaching the above-mentioned Vaikuṇṭha in the spiritual world by
  dint of their mystic yoga performance, perceived unprecedented
  happiness. They found that the spiritual sky was illuminated by highly
  decorated airplanes piloted by the best devotees of Vaikuṇṭha and was
  predominated by the Supreme Personality of Godhead.SB 3.15.26

This verse says that they have reached the Vaikuntha by  dint of their mystic yoga performance i.e. (YogMayaBala) (Yogic Powers). So they haven't used any technology but their own yoga power to reach over there.
You can read more about the story in this chapter of Bhagavatam.


Would flows execute before QCP script?

Question: This might be a fairly simple question but not much available documentation around it. I have a flow on SBQQ__Quote__c object which is making some field updates on related quote lines. I also have a QCP script in place which updates quote line fields. I am wondering what is the order of execution here, will QCP execute after the flow has finished? Or does the QCP run first? What happens if the flow is set to run asynchronously? Will the QCP run in parallel in such a case? Any pointers/inputs much appreciated. Thanks!
Answer: When you're not in the Quote Line Editor, the QCP is launched after Save, after the flow.
Technically, the flow updates the quote line record in the data base. This action triggers a CPQ re-calculation : information is then sent to CPQ servers that run all calculations (price rules & QCP) and insert the result back on the records.

Would flows execute before QCP script?


How to sort dd/mm/yyyy hh:mm by hours instead of date?

Question: I would like to take my current dd/mm/they hh:mm and sort by hours. At the moment it is sorted by date, however I would like to sort with hour going from earliest to latest in the day regardless of the date. Any help much appreciated.
Comment: You will need a helper column in which to store the hour: `=HOUR(A1)` then sort on that column.
Answer: You have to create a new surrogate column that contains the time portion:
=A2-FLOOR(A2,1)

and then you can sort by this column (you can even hide the column later if you wish):
Answer: Since Excel stores the date time value as the integer representing the number of days since 1900/01/01 (that day being day 1) and time as a decimal representing percentage of the day, you want to sort by the decimal value.  The following formula performs array like operations and therefore you want to avoid using full column references within the AGGREGATE() part of the formula.
=AGGREGATE(15,6,MOD($B$2:$B$11,1),ROW(A1))

MOD will return the remainder after being divide by a number.  If you divide your date time value by 1, only the decimal will be returned which is your time.
AGGREGATE function 15 will will sort a list from smallest to largest.  The 6 tells aggregate to exclude/ignore any error results.  The MOD(range) part is doing its job over a range of cells, so you will have a list of cells when MOD is finished and aggregate will sort them as previously mentioned.  ROW(A1) will evaluate to 1 telling aggregate to return the fist number in the list.  As the formula is copied down, the cell reference will increase by a row and you get 2, 3, 4, etc as you copied down.  In other words your sorted list.

Adjust cell references to suit your data.


Unable to Add User

Question: I am trying to add another user to my site. I am on Spark and with civihosting. When I click "create new account," I am redirected to a page that says "The website encountered an unexpected error. Please try again later." I've been having this issue for three days and can't figure out what the problem is. Everything else seems to be working perfectly fine.
Comment: I have mentioned this in the Spark channel on https://chat.civicrm.org/civicrm/. I suspect the first question will be; what CMS, followed by; what Extensions are on
Answer: It seems like you were missing the "Unsupervised" rule in CiviCRM (from Contacts > Find and Merge Duplicate Contacts).
The default rule, by email, was set as "General".
I changed it back to "Unsupervised".
It's rather odd that CiviCRM allows this, I will see if we can add a check against it.
Comment: https://github.com/civicrm/civicrm-core/pull/19064   /  https://lab.civicrm.org/dev/wordpress/-/issues/80
Comment: Added a simple system-check to the symbiotic monitoring extension for now: https://lab.civicrm.org/extensions/symbiotic/-/commit/8ba54131c23537957b5d172e581fb8a77959f85b

Unable to Add User


How can I show all contacts by default?

Question: When I click on the contacts tab I want by default to show all contacts? How Do I Do this?
Answer: This is a common question, but you're probably missing the point of this tab if you think that all it is for is showing a list of contacts. This is called the contacts home tab, and its purpose is to give you access to your recent contacts and some utilities, such as the import contacts wizard, mass deletion wizard, reports, and more (your features will vary depending on your permissions and organization edition/features).
However, if you're still intent on giving up all this extra functionality for the sake of going directly into a view of all contacts (from the contacts home tab, all contacts is just a click away by clicking on "Go!"), you can override the default page. Just remember, you won't be able to easily access the page at all if you choose to do this.
First, go to Setup > Develop > Pages, and click on "New." Give it a name, and enter the following code:
<code><apex:page action="/{!$ObjectType.Contact.keyPrefix}" standardController="Contact" recordSetVar="contacts">
</apex:page>
</code>
Next, go to Setup > Customize > Contacts > Buttons, Links, and Actions, click "Edit" next to Contacts Tab, and choose your new page.
Now, when you click on the Contacts tab, it will take you to your last list view. Simply choose the "All Contacts" view, and salesforce.com will remember this selection for you. However, you won't be able to click on any standard element to return back to the "home" tab, so you'll lose immediate access to the Tools and Reports quick links.
Comment: Firstly, I like your answer. Secondly, I think I read the question wrong. My impression was that on the Contacts Home Tab, is it possible to show the All Contacts list view instead of the Recently Viewed List View. I have wondered if setting a "default" list view is possible.
Comment: You get three views on the home tab: Recently Created, Recently Modified, and Recently Viewed. It's like the main home tab; it's just an overview, rather than a full list view.
Answer: You can do this with a bit of a hack and List Views.

Open the List View to show all Contacts.
Get the URL for that view. It'll be something like https://[instance].salesforce.com/003?fcf=[ListViewId]
Create a custom tab, All Contacts. Set the URL for this tab to be the URL from step 2.
If you want to replace the normal Contacts tab, set its visibility to "Default Off" for your users. Do not set it to Hidden or you'll disable searching for that object for those users.
Comment: Custom tabs are limited as opposed to Visualforce pages (unless they're on Unlimited Edition). This being said, this solution is equally valid to my proposal. And, it's usually a bad idea to link to a specific list view in case someone later deletes it.
Comment: Good point on this breaking if the list view is deleted.
Answer: For anyone who's having this issue 7 years later :)
Next to the name of the list view, there's a pin icon. Click it to pin the list view as your default.

How can I show all contacts by default?


How to setup multiple WANs with load balancing?

Question: What is the best way to setup multiple WAN's into a Ubuntu distro and load balance?
I have two internet connections, one static and one dynamic and I need to combine and load balance them. I have been looking into the following method http://www.netlife.co.za/archived-articles/12-started.html but was wondering if anyone had suggestions that were more Ubuntu specific or possibly other distro's that would work better for this.
Comment: A GUI tool would be awesome for the lazy amoung us, but I suspect this will be a heavily hackish solution.
Answer: As far as I know, Zentyal, previously known as eBox, offers that functionality, and it's easily installable on Ubuntu.
Version 1.4 is available from the repositories as eBox, and version 2.0 can be installed from an additional repository.
See here: http://www.zentyal.org/
And here is a nice detailed HOWTO: http://www.howtoforge.com/using-ebox-as-a-gateway-firewall-traffic-shaping-http-proxy-and-more
Answer: The primary problem is that while you can create configurations to load balance your outbound traffic, you won't be able to control your inbound traffic. The inbound traffic is aimed at a specific IP address, and each of your Internet connections has a separate IP, as assigned by the upstream provider. Doing this requires coordination with your upstream provider, and likely a full BGP configuration to publish alternate routes, etc. Doing bonding (combining traffic) would also need the upstream involved.
Comment: isn't a reverse proxy the right solution for load balancing inbound traffic?
Answer: Try out Zeroshell, bundled with an Linux.
Runs very smooth on low end h/w with no glitches.
Configuration options lets to play as you want.
Comment: Welcome to Ask Ubuntu! I recommend [edit]ing this answer to expand it with specific details about how to do this. (See also [How do I write a good answer?](/help/how-to-answer) for general advice about what sorts of answers are considered most valuable on Ask Ubuntu.)
Comment: Zeroshell is at EOL. However, the latest version is still downloadable as on date.


Help !!! 2007 Honda Accord 2.2 diesel not starting intermittently

Question: my Honda Accord has developed an issue where by sometimes it fails to start when the key is turned, it will turn over but not start, the green key light stays Stays flashing on the dash, does this mean the immobiliser system did not read the key? I brought it to a main dealer and thankfully the issue happened on them but they could not establish a connection and communicate with the ECU whenever green key was flashing, Strangely after numerous attempts putting the key into the ignition trying to start And whenever it accepted the key and allowed the car to start the diagnostic would communicate with the ECU and then scan would say no immobiliser faults?? There is a fault code in the log P0602,
Has anyone seen this type of issue before, the technician has never seen where they can't communcate with the key not reading, as they program new keys in that condition.where do I start replacing stuff??
Comment: Hi Guys, Just adding update info for this issue, the mechanic got it sorted, he had to replace the main engine ECU and recode it into the car. Problem gone for now at least.
Answer: FIXED FIXED FIXED Finally after tearing my car to pieces over the last four months I have finally fixed it,  intermittently not starting, green flashing key, no engine light when it won't start, no fault codes, checked keys, chips, fuses, relays, wiring loom, key reader, ignition barrel and on and on and on.
FINALLY bought an ecu of ebay that matched the number of mine of ebay for £35, plugged it in, garage plugged in a Snap on diagnostic tool to tell the car it had a new e u fitted, in the key/immobiliser section,, it paired with the 2and hand ecu and BOOOOM FIXED : )))), the hours I spent on forums trying to find a solution. : )


Where can I find a Dremora Markynaz?

Question: I recently obtained the Dead Thrall spell and have determined that the best choice for my Thrall, barring killing one of the unique people that can't actually be killed..., is probably the Dremora Markynaz. Being that their max level is just under the max 40 for the spell. I'm having a bit of trouble locating where any might SPAWN however. Does anyone know where they might be?
Comment: Since [Markynaz are a levelled spawn](http://uesp.net/wiki/Skyrim:Dremora#Melee_Fighters), your own level must be around the right range to have any chance to find them. Are you somewhere around level 36?
Answer: The Dremora Markynaz is a Level 36 Dremora.
Problem is: Dremora are rare in Skyrim, and they are levelled. There are some in the Shrine of Mehrunes Dagon and  Shalidor's Maze.
Now, due to the Respawning mechanics, it is likely that the few areas that do contain Dremora are fixed to levels that are way below the required level for a Dremora Markynaz to spawn (both are available rather early -- Labyrinthian - and by extension the Maze - is often an early target, and the Shrine belongs to a 20+ daedric quest).
That said ...
On PC, you can use Console commands to spawn Markynaz via placeatme <ID>. Replace <ID> by the respective ID from the Dremora list, and there you go.
There might also be a way to reset the level of a location via a command (resetinterior <cellid> looks promising but I can't verify that at this point).
Comment: Meaning that at lvl 60... I'm pretty much not gonna find one then, bugger.
Comment: I revoke former comment, the two inside Mehrune's shrine are always WAY under-leveled, even now they're only Kynval.
Comment: @Selonianth Is that one of the things fixed by the Unofficial Skyrim patch? (I know it fixes follower not-leveling)
Comment: @RavenDreamer no idea. I don't have a PC so therefore I don't have the Unnofficial Skyrim patch. But I don't mean that the dungeon doesn't level with me, it's rather that compared to the two blokes outside, Valkynaz I believe, they are roughly... well a hell of a lot easier to kill. At all times. I expect that if I hit level 70 or so without finding a favorite Dead Thrall they will be Markynaz for me.

Where can I find a Dremora Markynaz?


Rotation based on movement

Question: How can i calculate angle based on movement in C# XNA when i'm moving object with accelerometer? If object is moving up, sprite would rotate in corresponding direction. Should i use two vector coordinates(old, new) to calculate angle using Atan2?
Answer: Short answer: Yes.
Slightly longer answer: Maybe you want to add the accelerometer input to the objects velocity variable, so that there are no very sudden movement changes, when the accelerometer fluctuates. Then you would use the current velocity to calculate the objects angle (still using atan2).

Rotation based on movement


Does Visual Studio C/C++ support automatic software prefetching?

Question: Compilers like Intel and IBM's xlc can insert data prefetch instructions automatically.
I have some code that could be helped with prefetching at the cost of readability.  That is, there's a natural grouping of code like
<code>void foo(...){ // foo gets called frequently
...
char *myPtr = allocate(medium_size);
memset(myPtr,0,medium_size)  // cache misses here. medium_size is ~ 1 cache line
                       // Miss occurs on first access by memset, but not enough
                       // data to ameliorate by any hardware prefetching
                       // triggered by memset.  Basically foo() is called a lot
</code>
the cost of the cache misses incurred by the memset could be mitigated by pushing the allocate further up in the procedure and issuing a prefetch instruction immediately after, with enough instructions between it and the memset for there to be time for the data to be brought into cache.  In my case the code to calculate medium_size gets a little messy when pushed up further in the procedure, making it less readable.
If the compiler could reschedule the code for me to make the prefetch worthwhile (perhaps with the support of PGO) then I could get the best of both worlds.
So far it appears that Visual Studio supports only the intrinsics i.e. manual placing of prefetch instructions.  Am I wrong?

Clarification update in response to questions:
Q:How might the compiler improve the above code? A: the above code was just to give a flavour of what's involved.  The actual code is more complex, but boils down to an allocation and a store into it.  The reading is done by the memset as it writes to the memory.  On some architectures this may not trigger a cache miss, but on x86 it apparently does (according to vTune) (answered by markgz below).
Q: Won't just using memset be sufficient?  memset's memory access pattern is highly predictable and the hardware prefetching mechanism should handle it.
A: Yes, in general this is true and I did a poor job of explaining more of the context.
The routine (foo) containing the memset gets called very frequently, and it's the first memory access by the memset that triggers the cache miss.  There is not enough data for memset to ameliorate this miss through prefetching,  so I need prefetching involved before calling the memset.
Comment: It is very unclear how you hope the compiler is going to prefetch with this code.  It doesn't read anything.
Comment: The CPU must read the region being `memset` into the cache before it writes 0 to those cache lines, so while the code does not explicitly read anything, the CPU does.
Comment: In the case of `memset`, the processor's hardware prefetch mechanism will work just fine, and there is no benefit from adding software prefetch. (Based on the "Intel" reference above.)
Comment: Apologies, I did not explain enough of the context.  Updated.
Answer: yes, you can use
void _mm_prefetch(char*,int)


2003 Alero /highway /rpms

Question: I have 2003 Oldsmobile Alero, it runs at around 4000 rpm doing 55 and at 70 its close to 5000, i know this isn't normal.Is it not shifting correctly? I haven't noticed any issues with the transmission.Is it something simple im able to correct myself or more serious problem
Comment: What would normal RPM be for 70mph?
Answer: Depends on engine size /power ,but that is too much RPM . Any car I have had will be less than 2000 at 55 mph. Apparently your transmission is not up-shifting or the torque converter is stuck in " maximum ". I had an Olds with a defective torque converter stuck in "minimum" : the RPM could not reach 2000. You need transmission work which may be expensive but otherwise the engine will not last long at those RPM .( Yes , I know motorcycles normally turn at high RPM with no problem). My 3.5 L Nissan is 1600 RPM at 60 MPH.

2003 Alero /highway /rpms


Word for "taking advantage of a second chance or opportunity"

Question: Say a person doesn't act the first time around but gets a second chance and makes the right move. Is there any word that would describe such a situation or action?
Comment: Welcome to the site. An upvote to get you started.
Comment: This question could be improved if you provide more context (how do you hope to use the word? are you interested in phrases as well?) and tell us about the research you have done yourself to attempt to answer this question (for example, perhaps you have considered a phrase like *second time's the charm* but are looking for something else).
Comment: thanks all for the help. i'll do my best to put this into context, a sort of real life scenario. say a person sees someone and wants to say something but doesnt. what if that that person was provided another opportunity, get another shot. does a word exist that implies "second chance"...another opportunity to take the initiative..i dont know exactly what i am looking for but just something that describes that scenario. the antonym of Mamihlapinatapai. perhaps i should make it it's own question
Answer: How about "He redeemed himself"?
Answer: Didn't repeat his mistake, seized the opportunity, didn't squander/miss the opportunity.
I agree, some context would help.
Comment: I like the word "squander". Two syllables, flows of the toungue.. Is there any word that you could think of that reads similiarly but means the exact opposite of squander. Not a phrase like "didn't squander" but actually a word that means exactly that.
Answer: The word I would use to describe the person is retriever.


Is there is difference between 'upanishad embedded' and 'upanishad attached'?

Question: Is there is any difference between 'upanishad embedded in veda' and 'upanishad attached to Veda'?
Please give any example.
Answer: Those terms are superfluous and artificial. Upanishads were never separate texts in ancient or medieval times. They were just contiguous chapters in a Veda Samhita, Brahmana or Aranyaka.
Even in the commentaries of Sayanacharya (14th century), we don't find references saying "this Upanishad" or "that Upanishad". The reference is to a Vedic text, such as follows:
In the commentary on Rig Veda 6.9.5, he references Ishavasya Upanishad as "Vajasaneyakam":

तथा च वाजसनेयकम् - अनेजदेकं मनसो जवीयः ...

So the classical Upanishads are all only chapters in Vedic texts, that were specially studied in the context of Vedanta. In modern times, it became popular to only study Upanishads removed from their parent texts, in isolation.
So there is no "attached" or "embedded".


False oath on Allah

Question: I was in an argument with my sister because I was going to clean our fan with water by turning it off and she told my mother that I was going to clean it without turning it off  so I swore an oath of allah that I was not going to do it my intention was to say i was not going to do it without turning it off which is the truth but I don't remember if i said that I was going to do it with the fan off so does that count for a false oath if so does Allah forgive false oath on his name
Answer: Allah will not punish you for whatever you say unintentionally and your intention was not to give false oath, Allah says in the Quran; (Allah does not impose blame upon you for what is unintentional in your  oaths, but he imposes blame upon you for what your hearts have earned. Allah is forgiving and forbearing.)(2:225)

False oath on Allah


Display embedded symbols in the layout legend in QGIS?

Question: I have opened a MapInfo TAB file in QGIS ver 3.22.1 and can display the correct symbology by using "Embedded Symbols". The TAB file is a geology map and the only symbology relates to the geology polygons - so each rock type is coloured correctly. I have created a layout and have added a legend. The table name appears as a legend item but the symbols do not appear. the Attribute table has the rock-types assigned to the polygons (with other additional information) but there is no RGB information there to colour polygons manually via "Categorised" symbology.
How do you get to add the polygon colours for the rock types to the legend?
Comment: What happened when you save the layer in another file format and use the copy paste style tool ?
Comment: I exported as SHP format, copied the symbology from the TAB file and pasted to the SHP file. I get uncoloured polygons. On inspecting the properties of the SHP file, I see it has changed Symbology to "Embedded Symbols" - so doesn't actually copy and paste the symbols.
Comment: And if you use the option to save save the symbology in a file, can you use it back in your shp file ? What are the attribute existing for styling ?
Comment: Works the same as copy and paste... try to use "embedded
Answer: This functionality also supports the direct conversion of embedded symbol renderers into categorized or rule-based renderers. This enables QGIS to automatically create categories or rules which define symbology based on the relevant feature IDs.
So, before copying and pasting symbology settings, you can dublicate your .TAB layer in the layers window (table of contents)

and then switch the symbology to categorized mode (for both layers) as it is shown in the animated GIF in the link below:
https://www.qgis.org/ru/_images/3a408fbcff1ee8d5889c3fe30c0d9d831b050698.gif
And then copy symbology items from the layer, which symbology is based on the IDs

and paste to the layer with categorized symbology. (Copy from IDs based and paste to categorized). After all these actions you can export your symbology to .QML file


What is the relationship name of my wife's brother to me?

Question: What is the relationship name of my wife's brother to me?
Comment: possible duplicate of [Looking for a word meaning "the wife of one's brother".](http://english.stackexchange.com/questions/12585/looking-for-a-word-meaning-the-wife-of-ones-brother)
Comment: Not a duplicate, I think..."wife of one's brother" and "brother of one's wife" are two different things, it just happens we use the same word for them in English.
Answer: He is your brother-in-law.
There has already been a similar question posted here to which the answer was "sister-in-law", so I'll finish the list here:
Your spouse's brother or your sister's husband is your brother-in-law.
Your spouse's sister or your brother's wife is your sister-in-law.
Your spouse's father is your father-in-law.
Your spouse's mother is your mother-in-law.
Your daughter's husband is your son-in-law.
Your son's wife is your daughter-in-law.
Where applicable (and where disowning has not occurred), you child's same-sex life partner under a legal bond (whether marriage or civil union or what have you) or a bond you recognise even when the law does not would be either a son-in-law or daughter-in-law, as applicable.
Comment: @smithco: etymologically it originally meant that, but its meaning has since solidified to be essentially what's given here, no longer depending on the law.  And I get the impression that its meaning is currently shifting — roughly but not exactly in step with the law — to include same-sex marriages .
Comment: It has been a long time since marriage made anybody *de jure* father, mother, brother, sister, son or daughter to anyone else (with all the rights and privileges associated with blood relationships). The "in-law" relationships are only descriptive now, not legal.
Comment: Well, that's a much more thorough answer than mine, though I do quibble with the addition of "even when the law does not" as "in law" does etymologically derive from traditional common law.
Comment: The problem with shifting meanings is that they create confusion.  In this case, your expanded meaning of "in law" is actually the first time I have seen it used with that meaning.
Comment: I hear "in-law" used frequently to refer to the family of a life partner, whether legally married or not, and find such use perfectly unobjectionable and widely understood.
Answer: Brother-in-law is the usual term.


Why is unemployability still unaccepted?

Question: In some countries where there is serious shortage of skilled personnel or employable persons, it is common to describe the situation as a problem of unemployability. However, this word still appears to be unrecognized by most if not all dictionaries. Is there some better word or does it break any rule? Why has it been unaccepted for a long time?
Comment: I read the title and was wondering if this was a really right-wing social commentary!!!
Comment: It feels like "unemployability" would refer to a _person_ not being employable for some reason.
Comment: Everyone is able to be "unemployed" so the word "unemployability" would include everyone and be the same for all of them.  It shouldn't be used as a word meaning having low levels of employability.
Answer: Actually I can find this term in a most good dictionaries. May be it has not been a common term in the past,but  now, unluckily, the issue of unemployment is becoming  more and more a global problem, as consequence related terminology is becoming more widely used.
Comment: Define good dictionaries.
Comment: Comprehensive dictionaries?
Comment: unemployable (ˌʌnɪmˈplɔɪəbəl)
adj
1. (Industrial Relations & HR Terms) unable or unfit to keep a job
ˌunemˌployaˈbility n
Collins English Dictionary – Complete and Unabridged © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003
Answer: The Google Ngram Viewer is often useful to see the past popularity of words over the decades. Sometimes it's understandable - concerns about un/employability jumping up during the depression years, declining during the Second World War and the stability of the 50s. Sometimes it's no so obvious - why has 'employability' been recently booming, while other variants are in decline?
Answer: http://www.merriam-webster.com/dictionary/unemployable, http://www.oxforddictionaries.com/definition/english/unemployable, http://www.collinsdictionary.com/dictionary/english/unemployability.
Having said that, different dictionaries have their own standards as to when/why a word will get added or even left out. "unemployability" may get used, but certainly not as often as various other words, and no dictionary can include every single word in the English language.
The OED is probably the most extensive dictionary, but even then:

The Second Edition of the 20-volume  Oxford English Dictionary
  contains full entries for 171,476 words in current use, and 47,156
  obsolete words. To this may be added around 9,500 derivative words
  included as subentries. [...]
This suggests that there are, at the very least, a quarter of a
  million distinct English words, excluding inflections, and words from
  technical and regional vocabulary not covered by the OED, or words not
  yet added to the published dictionary, of which perhaps 20 per cent
  are no longer in current use. If distinct senses were counted, the
  total would probably approach three quarters of a million.

@Neil's Ngram link suggests that usage of "unemployability" may not be enough to guarantee it a place in each and every dictionary.
In general, using a word that does not appear even in any dictionary does not "break any rule". One of the reasons a word does get added is because of the ways in which and how often it is used - people were quite happily using "badassery", "selfie", and "twerk" before they were added by Oxford.
A word exists before it gets a dictionary entry - not the other way around. Dictionaries do not prescribe, but rather record, usage.
If you will be understood when you use a non-dictionary word, then feel free.


Sobolev trace theorem on Lipschitz domains

Question: Supposing that D is a bounded Lipschitz domain (and not smooth) in $\mathbb{R}^d$. From what I know, it is known that the trace operator is well-defined and continuous from $H^s(D)$ to $H^l(\partial D)$ when $l=s-1/2$ and $ 1/2<s<3/2$. My question is what happens when $s>3/2$, is the above result true? Also I am interested in versions concerning more general spaces like Besov or Tribel-Lizorkin.
Any answer or reference will be appreciated.
Comment: Should be l=s-1/2.
Answer: The problem here is with the definition of $H^\ell (\partial D)$. Typically, $\partial D$ is a manifold and you can define this set by local charts. In order to define $H^\ell (\partial D)$ with $0 < \ell \le 1$, it is sufficient to have bi-Lipschitz charts, whereas for $1 < \ell \le 2$ you would typically need diffeomorphisms with Lipschitz derivatives ($\mathcal{C}^{1, 1}$).
Going further, you also need to know how the boundary is attached to the domain, and this is the point of defining a Lipschitz domain by requiring the boundary to be a graph of Lipschitz function instead of say a Lipschitz manifold.
Answer: For Sobolev spaces $W_p^l(D)$, $l\in \mathbb N$, $1<p<\infty$, traces on a Lipschitz boundary $\partial D$ is considered in O. V. Besov, V. P. Il'in, S. M. Nikol'skii, Integral representations of functions and imbedding theorems, $\S20$, Theorem 20.12. Traces are completely characterised in the sense of necessary and sufficient conditions for a system of functions $\{f^{(\alpha)}\}$ on $\partial D$ to be traces of some function $f\in W_p^l(D)$ and its derivatives up to a certain order.


Make an affiliate link to the iTunes store without redirects?

Question: Apple has explained in "Launching the App Store from an iPhone application" how one can make an affiliate link to the app store and handle the redirect in background so it doesn't annoy the user.  But it would be even better not to have the redirect at all.  I seem to remember seeing a way to do that, but now I can't find it anywhere.
Is it possible to make an affiliate link from an iOS app to the app store without any redirect at all?
EDIT: To clarify, I am talking about a Linkshare affiliate link.
EDIT 2:  I'm getting closer.  I have this link, which I grabbed straight off of linkshare's "text links" page. When using k1th's trick below, works without any redirects on the iPad, but still has one redirect on an iPod touch [and presumably iPhone].  I speculate that the redirect may be to switch from top iPad apps to top iPhone apps, but I don't know that for sure.
http://click.linksynergy.com/fs-bin/click?id=sf2bW7QX/qU&offerid=146261.10005745&type=3&subid=0
Answer: Yes, you may have slashes in the params (that's because it's a slash after the question mark starting the parameter part of the URL.
Regarding skipping Mobile Safari to process the affiliate links:
You can either set up a hidden UIWebView to handle the redirect or do all that in the URL loading system yourself.
This is with a hidden WebView:
NSURLRequest *r = [NSURLRequest requestWithURL:[NSURL URLWithString:@"http://click.linksynergy.com/fs-bin/click?id=sf2bW7QX/qU&offerid=146261.431296703&type=2&subid=0"]];

testWebView = [[UIWebView alloc] initWithFrame:CGRectMake(0, 0, 10, 10)];
testWebView.hidden = YES;
testWebView.delegate = self;
[testWebView loadRequest:r];

the delegate:
#pragma mark - UIWebViewDelegate

- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType {

    if ([request.URL.scheme isEqualToString:@"itms"] &&
        [[UIApplication sharedApplication] canOpenURL:request.URL]) {
        [[UIApplication sharedApplication] openURL:request.URL];
        return NO;
    }

    return YES; // go on redirecting
}

testWebView needs to be an instance var and the view controller itself needs to be a <UIWebViewDelegate>. You also need to set the webview delegate to nil somewhere (e.g. in -dealloc)
Answer: I take it the reason you don't want redirects is to

avoid the Safari browser from popping up
avoid redirection within the App Store app itself

I would prefer k1th's solution, but failing that (I suppose it could fail #2 above), I assume the problem is that the first itms link is not the "final" one. One solution would be to simply hard-code the URL (or provide it by some other means):
- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType {
    NSURL myAppUrl = ....
    if ([request.URL.scheme isEqualToString:@"itms"] &&
        [[UIApplication sharedApplication] canOpenURL:myAppURL]) {
        [[UIApplication sharedApplication] openURL:myAppURL];
        return NO;
    }

    return YES; // go on redirecting
}

A cleaner solution would be to read the app ID off the itms link in the request.URL and format a new URL using the pattern that will take you directly to your app.
Answer: There is a much cleaner solution directly from Apple here: https://developer.apple.com/library/ios/#qa/qa1629/_index.html
And for brevity, here is the code from that page:
// Process a LinkShare/TradeDoubler/DGM URL to something iPhone can handle
- (void)openReferralURL:(NSURL *)referralURL {
    NSURLConnection *conn = [[NSURLConnection alloc] initWithRequest:[NSURLRequest requestWithURL:referralURL] delegate:self startImmediately:YES];
    [conn release];
}

// Save the most recent URL in case multiple redirects occur
// "iTunesURL" is an NSURL property in your class declaration
- (NSURLRequest *)connection:(NSURLConnection *)connection willSendRequest:(NSURLRequest *)request redirectResponse:(NSURLResponse *)response {
    self.iTunesURL = [response URL];
    return request;
}

// No more redirects; use the last URL saved
- (void)connectionDidFinishLoading:(NSURLConnection *)connection {
    [[UIApplication sharedApplication] openURL:self.iTunesURL];
}

Comment: That hides the redirect, which is an improvement.  But it's still there, and the resulting wait is reduced, but not eliminated.
Answer: I found this document and I think it's giving me the answer.  I always have a hard time deciphering these things, but I think it says that what I do is start with a basic link:
http://itunes.apple.com

then append a partnerId of 30, plus my linkshare affiliate token, which I think is
sf2bW7QX/qU

to end up with the following:
http://itunes.apple.com?partnerId=30&id=sf2bW7QX/qU

I got what I think is my id by following the instructions in the Apple doc, which basically say to grab the id parameter from a random linkshare link.  The link I used for the purpose was this:

I'm still quite unsure about the whole thing.  Can my linkshare affiliate token really have a slash in it?
Answer: This answers your question:
http://www.apple.com/itunes/affiliates/resources/documentation/linking-to-the-itunes-music-store.html#apps
BTW, I find this whole affiliate program too complicated.  I looked into it and I don't think it's worth the 5% commission.


Checked Out documents can't be found on local drives

Question: I'm using Foundation 2010 and when I checkout various documents they won't save on my computer. I've tried to play around with the Office offline editing options and the Sharepoint Draft file location but it still doesn't work. This is on a Windows 8 Computer using Office 2013 and IE10.
Answer: It sounds like maybe you're misunderstanding the "Check Out" feature. If you have versioning options turned on for the document library, checking out a document using the web interface doesn't download it, it just marks it locked for editing by the curent user. You'll still need to hit the "Edit" link to download and edit the file after you check it out.
The idea is that you're putting a reservation on it and might save it several times as you make changes, then check it in, creating a new version.
The documentation here might help?
Comment: From what i've seen, when you check out a document it says a temporary file in my documents Sharepoint Drafts, which allows you to edit the document. Once you check it in, it uploads it to sharepoint and deletes it from the drafts


Mass flow rate of evaporating water in a vacuum

Question: I'm melting ice in a vacuum using a heating plate, and attempting to condense any water vapor evaporated from the melted water onto a cold plate. Is there a way to describe the mass flow rate of the water vapor in terms of the power output of the heating pad and temperature of the cold plate (which remains constant through constant piping of liquid nitrogen)? Thanks for your help!
Answer: The rate of evaporation of water is related to the thermal power input and to the specific latent heat of water, which is the thermal energy absorbed by a unit mass of water in order to undergo a phase transition from liquid to gas. At standard pressure: $L_{water-SP}=2264.7 kJ/kg$.
Thus the mass evaporation rate would be $\dot{m}=\dfrac{P_{input}}{L_{water}}$, where $P_{input}$ is the thermal energy absorbed by the water per unit time.
In your case you need to find $L_{water}$ at zero pressure (since you are in vacuum). You also need to be aware that $P_{input}$, the rate of heat absorption by evaporating water from the surroundings, may or may not be the same as the power output from the heating pad in case your system is not closed.
Comment: What if the ice is sublimating in the vacuum? From ice at ~200k to gas at T>200k? is there a way to relate the thermal energy absorbed by the ice per unit time to the vapor pressure of the sublimated water vapor?
Comment: Hmm I can see a clear way. The pressure of water vapor depends largely on the details of the system and the efficiency of your condensation mechanism.
Comment: I can't* see a way


Is it possible to send multiple packets on a single link to a router?

Question: If we are sending packets to a router, are we only allowed to have 1 packet on the "link" at a time? So if I have 2 packets, do I have to wait for the first packet to reach the router before I can start transmitting the second packet onto link? This would mean that the transmission delay is lower than the propagation delay then if I am correct?
Answer: Packets are serialized and sent one bit at a time, and the bits from each packet cannot be mixed because the receiving end has no way to sort out which bits received belong to which packet, so one packet at a time is sent on a link.
Comment: Ahh, I see! This makes a lot of sense, I am still new to networking and I was under the assumption that the receiving end had a way to identify the bits for each packet. Thank you!
Comment: A single bit can only represent `0` or `1`, so there is no identifying information in the bit. Once enough bits have been received for the packet header, the receiver can see how many bits are in the packet and assign the rest of the packet's bits to the packet as it deserializes the bits.


Are different Linux/Unix kernels interchangeable?

Question: Can I take a Linux kernel and use it with, say, FreeBSD and vice versa (FreeBSD kernel in, say, a Debian)? Is there a universal answer? What are the limitations? What are the obstructions?
Comment: No, absolutely not. A good exercise would be to try it and see how it breaks. You can't even replace a Linux kernel with a much older Linux kernel reliably. Replacing userland tools is definitely doable though (if recompiled).
Comment: https://www.debian.org/ports/kfreebsd-gnu/ and https://www.debian.org/ports/hurd/ might interest you
Comment: @StephenKitt The reverse is true too :-) Especially when the software makes assumptions about being able to access `/proc`or other Linux-specific bells and whistles.
Comment: @Kusalananda regarding replacing userland tools, going from BSD to Linux can be painful: some BSD tools are quite hard to build on non-BSD systems... I've come across a few tools over the years which I would have liked to port, but it turned out to be non-trivial :-/.
Comment: What you can do is to take a x86_64 (linux) kernel and force-install it on i386 32-bit distribution (assuming a 64-bit intel CPU and support for 32-bit binaries compiled in). This is quite well known, but not immediately obvious...
Answer: No, kernels from different implementations of Unix-style operating systems are not interchangeable, notably because they all present different interfaces to the rest of the system (user space) — their system calls (including ioctl specifics), the various virtual file systems they use...
What is interchangeable to some extent, at the source level, is the combination of the kernel and the C library, or rather, the user-level APIs that the kernel and libraries expose (essentially, the view at the layer described by POSIX, without considering whether it is actually POSIX). Examples of this include Debian GNU/kFreeBSD, which builds a Debian system on top of a FreeBSD kernel, and Debian GNU/Hurd, which builds a Debian system on top of the Hurd.
This isn't quite at the level of kernel interchangeability, but there have been attempts to standardise a common application binary interface, to allow binaries to be used on various systems without needing recompilation. One example is the Intel Binary Compatibility Standard, which allows binaries conforming to it to run on any Unix system implementing it, including older versions of Linux with the iBCS 2 layer. I used this in the late 90s to run WordPerfect on Linux.
See also How to build a FreeBSD chroot inside of Linux.
Comment: Indeed @tonysdg, and believe me, [I know all about that](https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ec8b4b7085605e801a7740a2c3c33256aebe249c) :-/.
Comment: Some people have [quite strong opinions](http://www.firstruleofkerneldevelopment.com/) on how important it is to keep the kernel and user APIs synced :)
Comment: @mbrig: Until yesterday, it was there -- here's an archived version: https://web.archive.org/web/20171102142621/http://www.firstruleofkerneldevelopment.com/
Comment: @tonysdg I get a page not found on your link. (Unless that's a joke I'm missing?)
Comment: @StephenKitt: Ouch :( Sorry!! But major kudos for even having code in the kernel to begin with!
Answer: Some kernels have binary compatibility allowing you to mix userspace programs with different ABIs (eg freebsd can work with linux binaries to a degree) - however, the core binaries (eg the init program, the module loader, device driver setup tools, the C library, the tools needed to setup the filesystems... ) will in practice have too much need-to-know about kernel level interfaces to boot a system with a foreign kernel successfully.
Also, filesystems would need to be compatible.
Also, binary compatibility options would need to be compiled "hard" into the kernel - anything implemented as a kernel module would like fail because you could not run the module loader.
As mentioned, the user environments tend to be somewhat portable if you are willing to recompile - like freebsd-based debian systems, or setting up the netbsd pkgsrc system on linux (absolutely non trivial, but supported and possible!).


Co-signer taking over as primary when borrower can no longer drive

Question: My sister co-signed a car loan for me. Payments are current. I have had an injury and cannot drive. She wants to take over my car, which I'm fine with. How will this affect my credit? What needs to be done to remove my name?
Comment: Also, you should know that there is no such thing as "primary" when co-signing for the loan. As far as the lender is concerned, both of you are accountable for 100% for the debt.
Comment: Hi Julie, we need more info. Does your sister expect to gain any ownership in the car? Or does she just want to 'rent' it from you? Do you expect to retain any ownership? Who will be responsible for repairs/maintenance of the car?
Answer: She would have to buy the car from you, likely getting as new loan to do so. Lenders are not likely going to just "take your name off the loan". Understand also that her co-signing on the loan does not give her ANY ownership of the car unless you also put her on the title.
This is why it is SOOOO dangerous to co-sign a loan. If, hypothetically, you decided to stop paying the loan, she would have to keep paying it or ruin her credit, and she would have no right to take the car back or force you to sell it.
Comment: Comments are not for extended discussion; this conversation has been [moved to chat](https://chat.stackexchange.com/rooms/132609/discussion-on-answer-by-johnfx-co-signer-taking-over-as-primary-when-borrower-ca).
Answer: There are two things at play here:

The loan debtors; both of you

Do note that being a co-signer is all risk and no reward. Financially consider a co-signer as co-primary and understand the fact that she took a gigantic risk by co-signing.

The listed owner on the car title; presumably just you

Your choices include:
Let her make payments
The loan and title stays intact and she just makes payments.
You trust her to not screw up your credit just as she's been trusting you to not screw up hers this whole time.
Refinance
In order to get your name off of the existing loan it has to be refinanced. This costs money and her credit must be worthy of a solo loan.
However, the existing owner would remain on the title. I think you could change this at the DMV for a fee.
Sell the car to her
Make a legal transaction in which she applies for a solo loan and you sell the car to her making it 100% hers. This would terminate your co-signed loan assuming the sale price meets or exceeds the existing principal.
This would be advisable if your injury is permanent.

Additionally, the fairness of your existing and/or desired arrangement is a whole separate topic which is too lengthy to discuss here.
If you wanted to get into ownership percentages and fair sale price then these discussion topics will be the tip of the iceberg:

How much have each of you driven the car?
How much gas have each of you paid for?
How much maintenance have each of you paid for?
How much insurance have each of you paid for?
How much of the loan have each of you paid for?

It can get ugly real quick.
Answer: You won't be able to take your name off the loan. The bank has two people who must pay and hope it stays that way.
The simplest way is to lend the car to your sister, and she makes all the payments. If you trust each other 100%. Ask your insurance if they are fine with it.
Answer: Insurance needs to be taken into consideration. The car is owned by you. If you do not sell the car to your sister (good information in the other answers), then she cannot take out insurance on the car; you would have to maintain the insurance. You cannot insure a vehicle you do not have an interest in.


Process Workflow Rules

Question: Our current Work Flow creates tasks by a value in a custom field. This works fine. The issue is as each of the Work Flow process tasks are completed the value in the same field needs to change again triggering additional tasks. Id there a way to have the have the completed task change that field value?
Answer: You can use Process Builder and a Flow to update the custom field value.
Answer: Yes, you can update fields as part of Workflow under certain conditions. One case where you can't do it is if the field is Read-Only. For more on how to do this, I'll refer you to Workflow: Automating the Process and another helpful sheet titled Useful Workflow Rules. You'll also find additional assistance if you simply open up Help within Salesforce and look or search for Workflow.

Process Workflow Rules


How can I configure AUCTeX to use tab characters for leading indentation?

Question: I configure indent-tabs-mode to t so that tab characters are used for indentation by default. AUCTeX apparently changes the value of indent-tabs-mode to nil and uses some other system for handling leading indentation, and there are many customization variables in the groups "TeX Indentation" and "LaTeX Indentation". As far as I've found so far, these variables only allow you to change the number of space characters used for indentation. How can I configure AUCTeX to use tab characters for indentation?
Comment: I don't think you can have both AUCTeX-style of indentation and indentation with tabs.  If you want to latter, probably you only need to set `indent-line-function` to `'indent-relative` (its default value), in addition to setting `indent-tabs-mode` to `t`.  Is this what you want?
Comment: @giordano thanks a lot for those suggestions; I didn't know about `indent-line-function`. I've added a `'LaTeX-mode-hook` to force both of these variables and will see how it goes! If you want to submit this as an answer I'll accept it.
Answer: AUCTeX doesn't use tabs at all for indentation.  This is done by changing two variables: indent-tabs-mode and indent-line-function.  Thus, in order to get tabs back you can restore the default values of these variables (t for for the former and indent-line-function for the latter).  You can do this in your init file with a hook:
(add-hook 'LaTeX-mode-hook
          (lambda ()
            (setq indent-tabs-mode t
                  indent-line-function 'indent-relative)))


How to handle old URLs (from previous setup) after migrating to Drupal?

Question: What would the best way to setup (configure) URLs used in previous versions of a site after a site is converted to a new Drupal site?
Comment: Shouldn't this rather be moved to http://drupal.stackexchange.com ?
Answer: You want to consider using the path module.
If your old site followed a fixed scheme and you have a lot of urls, you might also be able to leverage the pathauto module. Here is a quote about it (from its project page):

... creates automatic path aliases for content, users, and taxonomy terms, eliminating the need to create them manually. This way, your site is more user and search engine friendly, and more descriptive about its content with less work from your side.
Answer: The best way is to write your own import module which uses path_set_alias() to assure that the url of the page on the new site is the same as that on the old site.  You can use Drupal's batch operations API to do this for you.  This gives you more flexibility than simply using pathauto.
If you aren't able to do this, try to approximate your old site's urls with pathauto.  Note that when you import, the paths probably won't be set with pathauto - you will need to go to the pathauto interface in order to generate these url aliases (they are called url aliases, since Drupal itself makes urls in a different way - but allows you to add url's to a page by means of these aliases).
If you're doing this for SEO reasons, you'll also want to find a way to add the canonical metatag for pages which aren't aliased, to prevent yourself from getting a duplicate content penalty.  Implementing this will probably vary, depending on whether you're using Drupal 6 or 7.  It seems that the nodewords module has this functionality for D6 - just a suggestion, as I haven't used it.
Answer: Modules that won't help
IMHO this question cannot be solved by either Path (core module) or Pathauto (contrib module), as suggested in one of the other answers. Because those modules serve another purpose.
Possible solution
However, a possible solution for addressing the issue as described in the question, is to use the Path Redirect module instead. Here is a quote about it (from its project page):

... allows you to specify a redirect from one path to another path or an external URL, using any HTTP redirect status.

The Path Redirect project page also includes some suggestions for related modules to be considered (which however serve another purpose related to paths).
Recommended solution
Yet another approach is to use Drupal's contributed module "Rules". Refer to my answer to the question "How to use the Rules module to implement a custom redirect for an outdated URL?" for (way) more details on that.


Social network dataset with features

Question: For a university project, I need a social network dataset, preferably from Facebook. The problem is that there are many data sets on the Internet, but all I've found contain information only about which users are friends. What I need is relationships + basic info about the user (age, gender etc.). Is this kind of information available? If so, where I can find them?
Answer: Here is some datasets that contains friendships and features for ego nodes.
Facebook, Google+, Twitter
But the following dataset is what you want i guess, it contains friendship relationships and features for every nodes:
Pokec Dataset
Pokec is a social network like facebook that is viral in Slovakia.

Social network dataset with features


In "Desolation of Smaug", why were Sauron's legions of orcs dispatched before Smaug had fallen?

Question: Why, in The Hobbit: The Desolation of Smaug would Sauron send his legions to Erebor before Smaug had fallen. It couldn't possibly be to negotiate with him. As powerful as Azog is in these films, I'm sure Smaug would just say no and eat him.
Comment: I can't recall much of the film. But in the books, Gandalf wanted Smaug out of the way because he thought it was likely he'd side with Sauron. So it isn't absurd that the Orcs were sent to negotiate.
Comment: Because the movie decided to add weird stuff that doesn't make alot of sense.
Comment: Haha gotta agree with you their, pj hobbit film just dont add up im still annoyed about the whole nazgul tombs thing
Comment: If you are talking about the orcs that were in the Battle of the Five Armies, I don't think they were Sauron's orcs.
Comment: Is there actually any indication in the movie that Sauron was sending his Orcs to Erebor?  I don't recall such.
Answer: Essentially, the films got several things wrong key to this story.
Azog is not even alive at the time of The Hobbit. Azog was killed at the Battle of Azanulbizar in 2799, while the events of the films take place in 2941.
The orcs at the battle of the five armies were not from Sauron. They were primarily from Mount Gundabad and Moria, as well as small colonies throughout the Misty Mountains.
Sauron was not openly very concerned with Erebor at the time. Sauron's focus was in returning to Mordor, though these preparations were not as obvious to the Wise, and so Sauron easily withdrew from Dol Guldur and into Mordor when the White Council moved against him.
So to analyze this situation from the book point of view is impossible. And to analyze it from the films can only be done by chalking it up to "the needs of the screen".