Did Star Trek invent the holodeck?

Question: I first saw the holodeck in Star Trek: The Next Generation. Had any other science fiction work used computer-programmable virtual recreation before Star Trek? If so, where was it first used in sci-fi?
Comment: It has to be a virtual reality you can physically walk around it, right? Not the kind where you lie down wired to a machine and have sensory inputs fed directly to your nervous system? That kind of set-up goes way, way back.
Comment: @user14111 : That was my interpretation, i.e. not a simulation achieved by direct interface with the brain or nervous system, and not through the use of VR goggles.
Answer: No, and the earliest "holodecks" were the nursery in "The Veldt" and the Surprise Chamber in Moscow-Cassiopeia.
Interestingly, something akin to the holodeck first appeared in the episode "The Practical Joker" of Star Trek: The Animated Series in 1974, 13 years before TNG.

That being said, Ray Bradbury's 1951 book The Illustrated Man features a short story called "The Veldt", in which a children's nursery can create material objects and environments at the whim of whomever is in the room.  I believe this is the first description in science fiction of a programmable, simulated, recreational reality (that doesn't involve direct interfacing to the brain or virtual reality goggles).

The nursery was silent. It was empty as a jungle glade at hot high noon. The walls were blank and two dimensional. Now, as George and Lydia Hadley stood in the center of the room, the walls began to purr and recede into crystalline distance, it seemed, and presently an African veldt appeared, in three dimensions, on all sides, in color reproduced to the final pebble and bit of straw. The ceiling above them became a deep sky with a hot yellow sun...
Now the hidden odorophonics were beginning to blow a wind of odor at the two people in the middle of the baked veldtland. The hot straw smell of lion grass, the cool green smell of the hidden water hole, the great rusty smell of animals, the smell of dust like a red paprika in the hot air...
"Walls, Lydia, remember; crystal walls, that's all they are. Oh, they look real, I must admit - Africa in your parlor - but it's all dimensional, superreactionary, supersensitive color film and mental tape film behind glass screens. It's all odorophonics and sonics, Lydia..."

The nursery in "The Veldt" is technology-based, and you "load programs" with your mind, i.e. the nursery connects to one's mind telepathically.  If you want an African savannah, it will give you one.  You can adjust the output by adjusting your thoughts / expectations, and so it is programmable in that sense.
If you are looking strictly for a holodeck that has an actual physical computer interface, I believe that the 1973 Russian-language film Moscow-Cassiopeia has the first. The device in the film is called the "Surprise Chamber", which is very similar to the Star Trek holodeck.
Comment: Good answer. Pretty sure the "hard light" version of the X-Men's danger room predates TNG as well.
Comment: @Omegacron : Thanks!  That's a good point about the Danger Room --- I agree.
Comment: looks like the "hard light" upgrade using Shi'ar technology was in 1991. The previous version with mechanical dangers still used holograms for illusion, though. So it might still count on a technicality.
Comment: Does the Krell machine in Forbidden Planet (1956) count? You can consider it a planet sized holodeck with the safeties off...

Did Star Trek invent the holodeck?


Losslessly compressing similar images?

Question: I need to reduce the size of my photo library so I naturally want to compress them. Many of them are not quite identical, but still very similar (subsequent shots of the same scene). Is there any compression algorithm that takes advantage of this fact to effectively compress these images? 7zip (LZMA) is useless.
Answer: You might try Paq 8 (fp8_v2.zip).  I just tried it myself on 1440 similar PNG images and then again on 111 similar JPG images.  Here are the results.

1440 PNG Files,  28,631,615 bytes => 2,058,653 bytes compressed
111 JPG Files,  15,003,820 bytes => 489,096 bytes compressed

Compression of the PNG files took about 8 minutes and 550 MB of memory when using:
fp8_v2.exe -7 images *.png
Compression of the JPG files took about 5 minutes and 125 MB of memory when using:
fp8_v2.exe -5 images image12*.jpg
See also: jpg lossless image compression test
Comment: 97% compression for the JPGs seems unrealistic.     The numbers in the comparison test you link to say the compression is about 20%
Comment: @OneSolitaryNoob Did you forget that the JPEGs are similar? 110/111 = **99.1%** expected compression. The comparison test that he linked is about compressing a single JPEG.
Comment: @Navin it's really unlikely.  Even if they look nearly identical most of the pixels will be slightly different.
Comment: @OneSolitaryNoob So what? 1 second of video (30 frames) can be compressed to about the same size as a single frame. As long as the slight difference makes up a small fraction of the data, you're all good.
Comment: @Navin thats lossy compression, many details are gone but most people won't notice.  Paq* is lossless compression
Answer: Here's a simple solution which doesn't work for photos but may work if one has several images with large pixel-by-pixel identical areas: save the images in an unpacked format like BMP (not PNG or GIF) and then TAR them and compress with a decent compressor like XZ, e. g. on Linux with something like
tar -c myDirectory | xz -9 >myDirectory.tar.xz

Instead of TAR and XZ, one may use 7-Zip with the "solid archive" option to get roughly the same performance. This way I could compress 16 similar screenshots, that took about 900 KB each when saved as separate PNG files, into a 2 MB archive. The benefit of this solution is that it uses common file formats, so it works without installing new software. (Unfortunately the older and even more common programs GZIP and BZIP2 didn't do a good job for me — maybe because the block size of BZIP2 cannot be configured to be larger than 900 KB.)
Comment: I tried this on 719 consecutive screenshots of my desktop taken every 2 minutes, with resolution 5920x2560. The total size of source PNG files was 1,797,639,471 bytes (1.7 GiB), when converted to BMP, 40.5 GiB. The resulting xz file was only 1,387,249,076 bytes (1.3 GiB). So this technique can be useful!
Answer: I would imagine that that the burrows-wheeler transform with an arithmetic coder would be ideal for this given a large enough window.  What happens if you configure BZIP2 to use a block size equal to a small run of photos?  It'll be slower and take more memory but the compression ratio should skyrocket. And have you tried LZMA with larger block sizes yet?
Answer: Not that I've seen.  Probably the closest thing would be taking several similar JPEGs and putting them into an MJPEG movie.  You could also use APNG or animated GIFs for a similar purpose.
I'm not sure how well that would work though, and it sounds like you're already talking about movie screencaps, so repacking them into a movie file sounds... counterproductive.
Maybe a better way, if you still have the clips that the screens came from, would be to simply find a command line tool that can extract the exact frame for you, copy that unique identifier into a text file someplace, and then you can always easily re-extract the frame when you need it.
Comment: GIF is not suitable for compressing photos, and animated GIF is even less. Even compressing photos to a MJPEG video does not seem useful in my eyes, because restoring single images would be difficult.
Comment: I didn't say it was a *good* idea...  :-) The ultimate idea was to put the photos into an animated variant of their original format.

Losslessly compressing similar images?


Screen turns black after a telephone call on a Samsung i9220

Question: The phone is fine. But. If... after I had a phone call on my Samsung i9220 then the screen turns black. If I press the button on the top right on the phones side I can see the "Desktop" for about ~0.5 seconds, but the screen turn black again. What could be the problem? The phone had been reseted several times and I can't find a setting for this in the "Settings". It has Android 4.1.1 and I think there is no update for the Samsung i9220 Android version yet, so it's up-to-date.
Answer: The problem could be your proximity sensor, which is located on top of the front of your phone. Basically the way it works is if you're on a call and you put your phone to your ear, the screen will go out to avoid your ear messing with the touch screen. If you are under warranty, have it checked on your nearest service center. I had this problem once, told my service center that I think the proximity sensor is the problem, then they fixed it in under 30 minutes.
Check out this question and install the apps from the top answer and see for yourself:
How do I test that proximity sensor on Galaxy Nexus works as expected
Comment: the problem was with the screen cover... I removed it and it doesn't goes black anymore... omg.. :D


Is regular charge cycling important to maintain battery health?

Question: I read about a full charge cycle at least once per month - how is this done? Just purchased this wonderful machine, brand new, want to keep it as perfect as possible, and am not sure how to do a full charge cycle of the battery.
Comment: A "charge cycle" just means letting the battery run down and then charging it back to 100%. Is that all you're looking for, or am I missing something?
Answer: FWIW, Apple's own advice no longer says cycling is recommended (but it used to) -- it now just focuses on things like turning off battery hogs like WiFi when not required, and storing the device half-charged if you're not going to be using it for a while.
Answer: You may get a lot of opinions on this, but essentially calum_b is correct that while Apple used to recommend doing at least a monthly discharge/recharge cycle, they no longer recommend this (but that's not to say they recommend against it either).
You can read the entirety of what Apple says about their batteries here.
In summary:

Charge your MacBook Pro battery as it suits you. You do not need to let the battery discharge 100% (or any percent) before recharging.
Apple have designed their lithium-ion batteries to reach 80% of their capacity quickly and then switch to a slower trickle charge to complete the other 20%.
Ambient temperature is a big factor in determining battery health/life. Your MacBook Pro is designed to work at its best when ambient temperatures are between 16° to 22° C (62° to 72° F).
Avoid exposing your MacBook Pro to ambient temperatures higher than 35° C (95° F)
If you ever need to store your MacBook Pro long-term without being used, then ensure it is switched off and the battery is only half charged.

Finally, you should know that the latest research (from late 2016) has found that the biggest enemy of lithium batteries is time. Regardless of how you use your MacBook, your battery will be far less healthy in five years than it is now regardless of whether you've cycled it daily or never at all.


Why were Burns and Winchester Majors, but Hawkeye and BJ captains?

Question: I guessed that draftees with lower levels of educational accomplishments got Enlisted ranks, whereas draftees with higher education got ranks of commissioned officers. But on what basis were they assigned differing ranks? Blake was lieutenant colonel, Burns and Winchester were majors, Hawkeye and BJ were captains, Mulcahy was a first lieutenant. Was it based on how many years of experience they had in private practice, or their age, or something else? If so, what was it?
Comment: I've found anecdotal evidence that doctors were drafted as Captains (preumably so they could order Lt nurses around) but then promotion was not guaranteed. Winchester certainly played the political game and had was an acknowledged expert. Frank not such a great doctor but could masquerade as a good administrator and be promoted.
Comment: Although it doesn't mention rank specifically, this answers a lot of those issues - https://movies.stackexchange.com/questions/15688/why-is-frank-burns-portrayed-as-such-a-child-in-m-a-s-h
Comment: @Paulie_D I had read that before posting this question. I'm interested in ranks.
Comment: @Paulie_D Not sure I agree there. BJ was a fresh recruit when he was introduced to the show; he started as a captain. There must be some military document explaining allocation of starting ranks. There was no evidence in the show of Winchester and Blake rising up in ranks. Only Burns got promoted off-screen.
Comment: https://tvtropes.org/pmwiki/pmwiki.php/Headscratchers/Mash
Answer: Burns was an ROTC and reached the rank of Major in the Army Reserves.
It's never explained how Winchester achieved the rank of Major, but it's assumed it's based on his tenure and expertise as a doctor.  Before being drafted, he was in line to be Chief of Thoracic Surgery at Boston General.
Hawkeye and BJ presumably went through the training program, as they were both very new to the profession, which made them eligible to be Captains without any real authority.  All doctors entered the Army as Captains.
Comment: M-A-S-H (hyphons instead of asterisks because of html markup) took place during the Korean War, but Blake is said to have earned a medal in WWII.  Presumably, he had just risen through ranks by that point.
Comment: I would add that Hawkeye and BJ (and previously Trapper) were very disinterested in seeking promotion as well.


Automatically workflow do not start

Question: We have a huge sharepoint list which restore more than 8000 items, there were 4 automatically starting workflows on this list. we made a change in list datasheet view for 600 items. after that, all the workflows remain at the starting point in all of our sharepoint list. Is there any issue on our services or ...?
Comment: They will all be completed eventually, SharePoint is protecting itself by throttling the requests, per the referenced TechNet article below.
Comment: Check SharePoint timer service is running or not
Answer: There is limit of workflows that can be started at the same time.
Microsoft documentation :

15 is the maximum number of workflows allowed to be executing against
  a content database at the same time, excluding instances that are
  running in the timer service. When this threshold is reached, new
  requests to activate workflows will be queued to be run by the
  workflow timer service later. As non-timer execution is completed, new
  requests will count against this threshold. This is limit can be
  configured by using the Set-SPFarmConfig Windows PowerShell cmdlet.
  For more information, see Set-SPFarmConfig.

https://technet.microsoft.com/en-us/library/cc262787.aspx#Workflow

Automatically workflow do not start


Is it necessary that the potential difference between any two equipotential surfaces in a system be constant?

Question: Is keeping $dV$ constant a necessary condition in the formula $$E=-\frac{dV}{dr}$$ for equipotential surfaces ?
Answer: Equipotential literally means "the same potential". So if you pick any point on one equipotential surface and pick any point on a different equipotential surface, if you know the potential on each surface then you must know the potential difference between those two points.
The equation you give $\mathbf E=-\frac{\text dV}{\text dr}\hat r$ is true in general for potentials with only a radial component.
Answer: Yes, because equipotential means that the potential is the same, so it's necessary to keep dV the same (constant) for both surfaces.


How can I track my bitcoins to the blockchain?

Question: I'm sorry if this is a stupid question; I'm just trying to learn more about Bitcoin and the blockchain.   How would I identify the bitcoins that are mine within the blockchain?    I can use Trezor to see my balance, but how would I find those coins within the blockchain without a 3rd party solution like Trezor?   I have used Blockchain Explorer but I used my transaction number or wallet address to find my coin balance. What if you don't have the transaction numbers or wallet address
Answer:
how would I find those coins within the blockchain without a [wallet]

One way would be to write down a list of addresses that your wallet reports as having a balance.
You can then enter those addresses into any one of the many "blockchain explorer" websites, the website will show you the balance for that address.

What if you don't have the transaction numbers or wallet address

There's generally no way to check the balance outside a wallet unless you have those pieces of information.
The Bitcoin blockchain does not contain any information about people or wallets. The blockchain is simply a list of transactions. For most standard types of transactions you can calculate addresses from the data in a transaction.
Addresses are just a number and are not like postal addresses or network addresses.
Answer:
Use your public address (like an account number) associated with your wallet.
Search for your address on a block explorer (like blockchain.com).
See your transaction history and balance.
Each transaction has a unique ID (TXID) for tracking.
Remember, private keys control ownership and transactions.

Understanding this helps you monitor your bitcoin activity and verify your funds on the blockchain. If I misunderstood your question, please point out


Equivalent of C library functions

Question: In C, almost everything requires a function. What nags me is that I don't know exactly what's going on. If there was no msvcrt.dll file, my C programs would all break because that's where all the standard library functions are. I would like to know what the equivalents to the standard library functions are, but without having to import stdio.h or stdlib.h. Is there a list of things you can do without the standard library's assistance? I would like to reach "pure" C without pre-defined functions.
Comment: Remove section 7 from [the C standard](http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1256.pdf) and you've got  your list.
Comment: You might enjoy working through the [Bare Bones tutorial](http://wiki.osdev.org/Bare_Bones) on osdev.org .
Answer:
Is there a list of things you can do without the standard library's assistance? I would like to reach "pure" C without pre-defined functions.

Think about the things you can do in C. Then remove the things that require pre-defined functions. That's what's left.
You could write your own strcpy or memset or sprintf, but there's no way to write printf in C without calling a pre-defined function. On Linux printf will eventually call write which is written in assembly; on Windows it will eventually call WriteFile from kernel32.dll which calls internal Windows functions that change between different versions of Windows.
Answer: A good chunk of the standard library is there to provide a portable interface to system-level functions, such as I/O, dynamic memory management, process management, time and date functions, etc.  Without it, you'd have to replicate all the low-level system calls yourself, at least some of which will have to be written in assembler (i.e., not "pure" C).
On a hosted implementation (basically, anything with an operating system), the whole standard library should always be available to you.  On a freestanding implementation, only a small subset of the standard library may be available, but on such an implementation you won't be doing anything that would require those functions anyway.
Answer: I didn't really understood what you willing to achieve.
You want to write c module where you don't want to use any standard library functions in it?
Example: The stdio.h header defines three variable types, several macros, and various functions for performing input and output.
In order to use fopen in your module you need to include the header file "stdio.h"
FILE *fopen(const char *filename, const char *mode)

Opens the filename pointed to by filename using the given mode.

If you don't want to use fopen then you need to write your own
  implementation of file open but that is reinventing the wheel.

If you intend to ask, you want to have own isalpha() or isnum() kind of functions to implement, you can write that on your own header, include that in your c source file.
Dynamic linking of DLL:
You can import dll, that is dynamic libraries, link those libs and use that function in your module. Even in that case you need to include the necessary header files.
Answer: Mentioning msvcrt.dll sounds to me like your real concern is proprietary windows-specific functions that might not be universally (or "eternally") available, thus breaking your applications if they (msvcrt.dll, etc, https://en.wikipedia.org/wiki/Microsoft_Windows_library_files ) are dependencies. I think you might be happy/content using Posix standard library functions, see, e.g., https://stackoverflow.com/questions/9376837/difference-between-c-standard-library-and-c-posix-library or https://en.wikipedia.org/wiki/C_POSIX_library for which the source code is freely available, e.g., https://www.gnu.org/software/libc/
So maybe what you want to do is determine which windows standard library functions are identical to posix counterparts, and restrict your application code to that subset. It's kind of impossible to do anything non-trivial without using any standard library stuff whatsoever.

Equivalent of C library functions


Changing Direct Speech to Indirect Speech

Question: The bus conductor explained,"This seat is set aside for monks".
If I change it into Indirect Speech,will I need to change the demonstrative adjective "this" to "the"? For example:"The bus conductor explained that the seat was set aside for monks." Thanks a lot.
Answer: The bus conductor explained, "This seat is set aside for monks".
In indirect speech, this will be changed to that.
The bus conductor explained (that) that seat was set aside for monks.


Why does my right elbow joint make a popping noise when I do pullups, pushups or dumbell curls?

Question: Everytime I do these exercises, specifically pull ups and push ups, I always hear a popping or cracking noise only in my right elbow for some reason. Even from stretching it, it still makes this sound.
Also, when I do forearm curls my right wrist only is always hurting.
Why is this?
Answer: Crepitus, or crepitation, describes any grinding, creaking, cracking, grating, crunching, or popping that occurs when moving a joint.
If you experience those sounds then it does not necessarily mean anything is wrong. However, if those sounds are accompanied by joint pain or swelling, then there may be an injury that requires treatment.
I would see a doctor to get a diagnosis.


How much gold do champion kills give on Proving Grounds?

Question: There is a reduction in gold per champion kill on Proving Grounds. I play a lot of it, but never really had the time to watch for the gold gain because, unsurprisingly, I'm usually in combat when I get kills. So how much gold does a kill get you, including when the target has a kill/death streak?
Answer: Tl;dr - Gold is distributed diffrent in Proving Grounds than in the Summoners Rift. Focusing on killing dominating players are more rewarding than in other League of Legends game types.
I played ARAM moment before and I do some math based on my observations. I can't be sure about gold per kill but I will be sure about killing players and this should show me some rules behind it.
I also make an assumption that Riot based values on V188.8.131.52 Summoners Rift gold per kill values. With this you can see some pattern here.

1st kill ? 47% ~ 140 gold - which confirm @Julian G. post.
2nd kill ? 52% [+5% Change]
3rd kill - Killing killing spree player is 237 G comparing to 408 (58%) [+6% Change]
4th kill - Killing rampage player is 308 G comparing to 475 (65%) [+7% Change]
5th kill ? (72%) [+8% Change]
6th kill - Killing dominating player is 520 G comparing to 647 (80%)

Normal reward growth is 20%. In Proving Grounds it growing from 5% to 10% - probably.
Pics with data  and .
Comment: You may want to use the Print Screen key to take screenshots in the future, rather than your camera.  The quality leaves much to be desired.
Comment: @CurtisTasker - I was playing on iLoL Mac Beta. There aren't such key as a Print Screen on any Mac keybord and doing normal Print Screen key combination don't work with this app. I'm waiting for your better resolution pic and answer in this topic :) !
Comment: On a Mac, press command+shift+3 :)
Comment: @CurtisTasker As I said "doing normal Print Screen key combination don't work with this app". I'm still waiting for your screenshot :>
Comment: Funny, the screenshot key combo works fine for lol on my mac.  Honestly I don't even think a screenshot is necessary to answer this question, it just irked me that you posted a cameraphone picture of a computer screen :)
Answer: If you are doing a custom game of ARAM on Proving Grounds, Champion kills are worth 140g.
Here is a video showing a kill from Nidalee:
Nidalee ARAM kill
I started at right before she gets the kill but you can start it from the beginning.
Answer: From the research that I have done I believe that you receive the same amount of gold as if you were playing summoner's rift, but while in the proving grounds you receive a constant stream of gold and experience.
Comment: That's definitely not true. First Blood gives only 200g instead of 400, and for shutting down a legendary streak you get 400 instead of 600. That's pretty much all I can remember for sure though.


Is there a combinatorial interpretation or bijective proof for this Catalan number identity?

Question: Is there any combinatorial interpretation or bijective proof for this identity
$$2C_n=4{2n \choose n}-{2n+2 \choose n+1}$$
where $C_n$ is the sequence of Catalan numbers?
Answer: There is an obvious bijective proof of the identity
$$ 2 \binom{2n}{n} + 2 \binom{2n}{n + 1} = \binom{2n+2}{n+1}$$
and also a bijective proof of
$$ 2\binom{2n}{n} -  2 \binom{2n}{n+1} =  2C_n,$$
see the paragraph "second proof" in the wiki page. By combining the two, you get a bijective proof of your identity, in the form
$$ 4 \binom{2n}{n} =\binom{2n+2}{n+1} + 2C_n  .$$
Answer: In the wikipedia page on Catalan numbers there is the following:
"There are many counting problems in combinatorics whose solution is given by the Catalan numbers. The book Enumerative Combinatorics: Volume 2 by combinatorialist Richard P. Stanley contains a set of exercises which describe 66 different interpretations of the Catalan numbers."
I guess it is a good place to look for an answer.


Android non-blocking file i/o?

Question: I'm currently writing an async i/o library for Java that has a very similar API to Node.js. I could do the socket part with nio, but there seems to be no FileChannel that extends SelectableChannel so I can't do the file i/o with nio, too.
In Java 7 they added AnsynchronousFileChannel, which allows non-blocking file i/o. Unfortunately, Android does not support it. Is there an equivalent class on Android to do non-blocking file io?
You can find the library here: https://github.com/VanCoding/Node.java
A sample App is located here: https://github.com/VanCoding/Node.java/blob/master/src/node/examples/App.java
Answer:
Is there an equivalent class on Android to do non-blocking file io?

Other than your wrapping traditional I/O in a background thread, no, sorry.
Comment: That's sad :( I hope Android will get such a thing in the near future!

Android non-blocking file i/o?


Password protect a folder

Question: What are the available options for password protecting a folder? I'm talking about requiring a password to actually access the folder, not just user access rights. Is the third-party software out there secure and stable? What are the recommendations?
Comment: This is a great question (I just asked and almost duplicate myself). Could someone with the required rep re-tag this as windows XP and Vista? Then it is a little bit less specific and the accepted answer still holds.
Comment: I have retagged to a generic Windows tag
Comment: oops, just retagged to windows-xp windows-vista...sorry didn't see the comment
Answer: My Lockbox™ is security software enabling you to password protect any folder on your computer.
The protected folder (lockbox) is hidden from any user and application of your system, including Administrator and System itself. It is impossible to access the lockbox, not only from the local computer, but also from the net.
The program is extremely easy to use. You can set the lockbox location and the password during the setup procedure. After the setup is done, lockbox will be hidden and locked until you enter the valid password.
Folder Lock is a Windows program to encrypt or password protect files, folders, removable drives, partitions, USB sticks, etc. In encryption mode it uses the strong 256-bit AES encryption algorithm to encrypt objects on the fly. In lock mode files, folders and drives are not encrypted, but protected with a password.
Folder Lock is shareware ($39.95), try before you buy.
TrueCrypt and FreeOTFE are powerful (and free) alternatives, but it might be an overkill for what you have in mind. They don't encrypt separate folders, but rather an entire filesystem (either a file-based "volume" or a whole disk).
Comment: I am a fan of truecrypt(additional + because it's free).  Now that you have an encrypted drive you can use subst to put the "drive" where a folder should be...might take a couple more steps, but it's a free solution that just works.
Answer: If you have Windows 7 Ultimate or Enterprise, I would suggest encrypting a partition with the built-in-tool BitLocker and storing your folder within that partition. You can also use a USB drive for that purpose.
I somehow don't trust third-party software with something as important as encryption. I usually avoid them and suggest against using them.
Answer: PC Security™

PC Security™ is the ultimate in computer security, offering multiple locking systems for the windows environment and internet. Lock files, monitor programs activities, even detect intruders! PC Security offers flexible and complete password protection, "Drag and Drop" support, plus many other handy features. All together, an incredible security package.
Answer: While I'm not 100% about actually password-protecting a folder, you could zip or rar the folder and password-protect it. Alternatively, I could recommend TrueCrypt which has already been mentioned.
Answer: You can try Private Disk. It creates a virtual disk inside your system, encrypting it with AES-256. The program is extremely easy to use.
Although it doesn't password protect a folder, I think it is a better choice.
The problem with the "password protected folder" paradigm is that such software needs to somehow integrate into Windows Explorer (otherwise the protected folder wouldn't appear as a folder). Besides that, it means that it will only work with Windows Explorer or some built-in file browser.
This imposes some constraints, rendering other programs unable to interact with the protected folder.
Private Disk's approach is fully transparent. Any program will be able to work with the encrypted volume as if it were a regular one.
Answer: Unfortunately Windows 7 does not seem to support password protection of folders. This only appears to be possible through Windows authentication, i.e. changing the security permissions of the folder to only be accessible to certain users.
See this article for more information.
Alternatively, you could use a third-party application to protect it. There are plenty of these floating around on Google :)
Comment: -1: He was specifically asking for third-party software.
Comment: read the question again buddy..

Password protect a folder


Is this homebrew Oath of the Golden Knight paladin subclass balanced compared to the official subclasses?

Question:
Oath Spells
  You gain Oath Spells at the Paladin levels listed.
  3 Hail of Thorns, Ensnaring Strike
  5 Locate Animals or Plants, Healing Spirit
  9 Conjure Animals, Spirit Guardians
  13 Grasping Vine, Polymorph
  17 Tree Stride, Insect Plague
Channel Divinity
  When you take this oath at 3rd level, you gain the following Channel Divinity Options:

Life Sequester:
  Over the course of ten minutes, you transform a small or smaller non-magical object, or a willing creature you are touching into a beast of CR 1/8 or lower, expending a use of channel divinity.  The character's armor and equipment is absorbed into it while it is transformed, and the creature gains no benefit from its armor and equipment.  The character retains the intelligence, wisdom, and charisma scores it had before being transformed.  The character or object returns to their original form after 8 hours or after being reduced to 0 hit-points.  If you transform an object with this feature, the beast it turns into is neutral towards you.
Golden Knight:
  As an action, you use your Channel Divinity to summon an Animated Armor that appears in an unoccupied space within 10 feet of you.  The Animated Armor vanishes if it is reduced to 0 hitpoints or if it goes more than 10 feet away from you, or after one minute.  The Animated Armor is friendly to you and your allies and obeys your commands.

Aura of healing:
  At level 7, whenever you cast a paladin spell, you can choose a humanoid ally within 30 feet of you.  They regain hitpoints equal to the level of the spell you cast plus your proficiency bonus.
Superior Summons:
  At level 15, whenever a creature does damage to a creature you have summoned with a paladin spell or Channel Divinity, you can use your reaction to make the attacker take magical bludgeoning damage equal to the damage it dealt (to a maximum of 40 damage).  Once you use this feature you cannot do so until you take a long rest.  Additionally, when you fail a saving throw to maintain concentration on a spell, you can use your channel divinity to attempt the saving throw again instead (you must accept the results of this new roll).
Field of Futility:
  At level 20, as an action you undergo a transformation that lasts for one minute.  While under this transformation you gain the following benefits:

You can cast counterspell as a 3rd level spell at will without expending a spell slot.
When you hit a creature with a critical hit, that creature takes an additional 4d10 necrotic and 4d10 psychic damage.
You are immune to radiant and necrotic damage.

Once you use this transformation, you cannot use it again until you complete a long rest.
Comment: Also, is there any kind of theme/lore for this subclass? The abilities all seem kinda unrelated, but maybe I'm just missing something.
Comment: @Medix2 the creature can be any size, but since there are no CR 0 or 1/8 creatures larger than medium its not really an issue.  Yes, excess damage applies as per the druid rules.  Yes, as it says the Animated Armor disappears. I put a damage cap so that way if a BBEG uses a super powerful attack on a summoned creature he's not instantly defeated.  The saving throw feature is for any spell, hence the "additonally".  For field of futility, the additional damage is added after the crit.
Comment: Please explain what the class means and where it draws its power from. Also, the Golden Knight ability is non-scaling for some reason and is garbage at high levels
Comment: @Medix2 yes____
Comment: For Life Sequester, can the creature be any size? Does excess damage past being reduced to 0 HP apply to the creature's original form? For Golden Knight, I assume the Animated Armor disappear any time you and the armor are more than ten feet apart? For Superior Summons, how did you come to the maximum damage of 40? Does the remaking a saving throw apply to any spells and not just summons? For File dof Futility, I assume the additional damage when getting a crit is not then *doubled* by the crit to 8d10 of each?
Comment: I assume that if you turn an object into a creature with Life Sequester it has the base stats for a creature of its type? It does not currently say so, just that it retains the original (non-existent) scores.
Comment: @Erik, yes it retains its non-existant scores.  A rock would be quite dumb.
Comment: @Zobrothian it still is good because it is one more target for enemies to attack instead of you, and it could be ordered to take the Help action and give you advantage, plus Superior Summons gives it a significant power at higher levels
Comment: I assume it's intended that if the animated armor is 10 feet from the Paladin it can be killed by simply shoving it?
Answer: In terms of balance
Most of this subclass seems fine, although a few of the features I'd probably buff a little bit, if only because they're otherwise quite difficult to use.

Channel Divinity: Golden Knight. I would revise the wording to "The Animated Armor vanishes if it is reduced to 0 hitpoints, if it ends its turn more than 10 feet away from you, or after one minute.". Otherwise, it requires very finicky movement tricks to move around the battlefield.

Alternatively, if the intent is for the Animated Armor to be leashed to a specific point in space, I would just rewrite it as "if it ends its turn more than 10 feet away from where it was summoned". Either of these would be a lot better for the overall behavior of the creature.

Superior Summons. There's really no good reason to cap the damage at 40 damage. There's already plenty of features in the game that deal retributive damage to a target—see, for example, the Oath of Redemption's Channel Divinity: Rebuke the Violent, which at level 3 allows the paladin to do exactly this, without a damage cap, once per use of Channel Divinity, with the only mitigating factor being a Wisdom Save for half damage instead—and there's already at least one feature that allows a PC to immediately deal lethal damage to any creature, mitigated only by a single saving throw—that would be the Way of the Open Hand's Quivering Palm, which costs only 3 Ki points (itself a resource that recovers on a Short Rest). So since this feature is already limited by being usable once-per-long-rest, I don't think there's any need to further limit its capabilities in this way.
Superior Summons, Additional Effect. I would just make this limited by one use per short rest. Tying this feature to the Channel Divinity feature essentially means you're giving the Paladin 3 Channel Divinity options, breaking the common design convention of only giving a Paladin (or Cleric) 2 Channel Divinity options, and being able to reroll a single concentration save is probably never going to be worth sacrificing your Channel Divinity (or, more likely, withholding their Channel Divinity explicitly for its use), itself already core to most of the rest of the class features.
Animated Armor. Given that this creature is going to be summoned at all levels of play, it might make sense to give it the capacity to scale with the paladin's level. I recommend using the Artificer's Homonculus Servant (Eberron: RftLW, pg. 62) as a template for homebrewing a creature that could be summoned in the place of an Animated Armor (you'll probably have to dial the hit points back a bit, maybe more like 3 hit points per level instead of 5).

In terms of Theme
A lot of those balance issues are pretty minor, in my opinion, and easy to deal with. The bigger issue with this homebrew, in my opinion, is that it's a little bit scattershot in terms of the gameplay style it facilitates. The subclass is called the Oath of the Golden Knight, and its Channel Divinity features facilitate summoning creatures, but its Oath Spells list seems to instead be split between nature-themed spells having to do with control (Ensnaring Strike, Grasping Vine) or summoning, and its level 7 feature (ostensibly replacing the "Aura" most paladin Oaths grant at this level) instead promotes their healing ability. There's a bit of a mismatch between what the features are permitting this Paladin to actually do, and what this Paladin Oath is intended to do.
I would consider revisiting both these features, thinking about a different level 7 feature that would better fit with the other features granted by this class, and thinking about reconsidering the spell list granted to this character, perhaps to focus more on buff spells—spells like Bless or Mantle of the Crusader would be especially appropriate for this class.
Comment: +1 for the theme mention. Reading through the original post, I still have no idea what the theme is supposed to be behind this paladin, or what it's gameplay group purpose is. It's all over the place and seems to not have any coherent theme.
Comment: +1 for the second half of this (I mean, +1 for all of it, but the second half in particular); this was my first thought as well, but you've worded it better than I ever could.
Comment: Though it should be mentioned that not every class and subclass need a strongly defined theme and/or purpose, because not every individual is completely focused on exactly one purpose, be it by character or training. If a player wants to play a more "scatterbrained" class that has an acceptable power level for its RP, that's fine in my opinion.


iOS webRTC library supporting both armv7 & arm64

Question: How can I get the webRTC library which will support for both armv7 & arm64 in iOS?
Answer: You are lucky. I have just finished to integrate webrtc in my project for couple days. My solution as below:

Combine all *.a you built for armv7 to libWebRTC-armv7.a: Using command lines as below
libtool -static -o src/out_ios_armv7/Release-iphoneos/libWebRTC-temp.a src/out_ios_armv7/Release-iphoneos/*.a
strip -S -x -o src/out_ios_armv7/Release-iphoneos/libWebRTC-armv7.a -r src/out_ios_armv7/Release-iphoneos/libWebRTC-temp.a
Combine all *.a you built for arm64 to libWebRTC-arm64.a:
libtool -static -o src/out_ios/Release-iphoneos/libWebRTC-temp.a src/out_ios/Release-iphoneos/*.a
strip -S -x -o src/out_ios/Release-iphoneos/libWebRTC-arm64.a -r src/out_ios/Release-iphoneos/libWebRTC-temp.a
Create your libWebRTC supported both armv7 and arm64:
lipo -create src/out_ios_armv7/Release-iphoneos/libWebRTC-armv7.a src/out_ios/Release-iphoneos/libWebRTC-arm64.a -output libWebRTC.a

P.s: Just build your armv7 library to separated folder with arm64:
export GYP_GENERATORS="ninja"
export GYP_DEFINES="build_with_libjingle=1 build_with_chromium=0 libjingle_objc=1 OS=ios target_arch=armv7"
export GYP_GENERATOR_FLAGS="$GYP_GENERATOR_FLAGS output_dir=out_ios_armv7"
export GYP_CROSSCOMPILE=1
pushd src
gclient runhooks
ninja -C out_ios_armv7/Release-iphoneos AppRTCDemo
popd

Answer: You can refer to our blog:
http://io.diveinedu.com/2015/02/02/%E7%AC%AC%E4%BA%94%E7%AB%A0-WebRTC%E7%9A%84iOS%E6%A1%86%E6%9E%B6%E7%BC%96%E8%AF%91.html
I have wrote a shell script to build WebRTC sources to a framework(excluding the apprtc signaling library) for iOS use.
If you cann't read Chinese, you just read that script embedded in that blog, it's enough! aha.
./build_webrtc.sh build_all

There may be a bug in armv7 device. that bug was caused by a stack over flow issue in VP8 decoding in armv7 neon function.
You can confirm this patch to fixes crash for it:
diff --git a/source/libvpx/vp8/common/arm/neon/vp8_subpixelvariance_neon.c b/source/libvpx/vp8/common/arm/neon/vp8_subpixelvariance_neon.c
index 8308d55..a66b6f5 100644
--- a/source/libvpx/vp8/common/arm/neon/vp8_subpixelvariance_neon.c
+++ b/source/libvpx/vp8/common/arm/neon/vp8_subpixelvariance_neon.c
@@ -1003,7 +1003,7 @@ unsigned int vp8_sub_pixel_variance8x8_neon(
         const unsigned char *dst,
         int dst_stride,
         unsigned int *sse) {
-  DECLARE_ALIGNED_ARRAY(kAlign16, uint8_t, temp2, kHeight8 * kWidth8);
+  DECLARE_ALIGNED_ARRAY(kAlign16, uint8_t, temp2, kHeight8PlusOne * kWidth8);
   DECLARE_ALIGNED_ARRAY(kAlign16, uint8_t, fdata3, kHeight8PlusOne * kWidth8);
   if (xoffset == 0) {
     var_filter_block2d_bil_w8(src, temp2, src_stride, kWidth8, kHeight8,

Wish this can help you!
The students of diveinedu.com have just overcome and fixed this bug.
Comment: I have followed your tutorial, but when the script works on combining the libraries armv7 and arm64, there and error comes up that both libs can't be of the same structure.

Also I tried running the arm64 build on iPhone 6 and iPad 3, the error I receive is of invalid architecture.
Answer: thanks phuongle, this really works...
...but with a twist...
...as Omer Waqas Khan noticed, there might be a case where one might encounter the error message (while lipo-ing): both libs can't be of the same structure.
Of course, I went WTF...lipo, what's wrong with you...they are of different structure...I BUILT THEM THAT WAY...
But then I set out to double check it:
 - I went in the folder where I had the arm64_merged lib and...
lipo -info lib's_name.a

It reported back of being of both armv7 and arm64 type. Puzzled, I then...
lipo -info *.a

...all the libraries (72 of them) reported being of type arm64 except for 2...
libisac_fix.a
libisac_neon.a

For whatever reason they were armv7.
Earlier in the day, I was using a "a few days old" clone of the webrtc thingy. Back then, I remember always obtaining only 70 libraries. But then, for other reasons, I decided to
gclient sync

After that, I ended up with 72...as such, I just removed the libisac nonsense. Now the 2 fat_libs were of different types and I could successfully lipo.


Can I boot straight into bash from a USB drive installation?

Question: I need to boot from a USB drive installation of Ubuntu 10.10 to do some maintenance on an older machine, and I don't feel like waiting for five minutes for the gnome to log me in. Is there a boot option that I can specify that will allow me to boot straight into bash?
Answer: You can install to your usb the server edition iso without the graphical interface so you boot straight into console.
From the normal ubuntu desktop booting iso in the begging you have 3 secs when you are show the icos keyboard and human. If you press any button you can execute commands on bottom to pass parameters.
Comment: Perfect - just the answer I was looking for. Thank you very much!
Comment: @kivetros you are welcome :)
Answer: At the first textual menu, where you can choose to start ubuntu, check the disk or boot from first hard drive, press F6 for option, then ESC to dismiss the option menu.
You should see the boot options line, ending with two dashes.
Before the dashes, after quiet splash insert init=/bin/bash and press enter.
After some errors, you should reach a shell prompt.
Answer: I have never booted directly off of a usb chip, but it sounds like the same kind of thing as booting off a CD. At one point, there was a menu when you first start the cd with different options such as:

Try Ubuntu without making changes to your computer
Install Ubuntu
Recover a Broken System
Etc.

This is still there, but you have to put in some input first. When you see the purple screen with the keyboard and accessibility icons, press an arrow key on your keyboard. This should give you that menu. Choose "boot from first hard disk" and you now boot from the HDD without removing the flash drive.
Hope this helps, your question was a bit confusing.
Comment: That is not at all what I want to do. I want to start Ubuntu without starting `X` so that I don't have to wait for `gnome` to load before I get to work. All I need is a Terminal (aka `bash`) window.


About normal Zeeman effect and Hydrogen atom

Question: I think that the normal Zeeman effect is experimentally observed only when we can neglect the spin i.e. if we consider a spin-singlet state with total spin $S=0$. Since in the hydrogen atom there is only one electron, we cannot observe the normal Zeeman effect in the Hydrogen atom. Am I right?
Answer: Yes, you are correct. The "normal" Zeeman effect refers to the splitting of spectral lines into an odd number of components, which could occur for integral orbital angular momentum (e.g., the $M_L = -1, 0, +1$ levels of a $p$ orbital). When there is a single unpaired electron spin, $S=1/2$, so an even number of spectral lines results and this is called the "anomalous" Zeeman effect. In the hydrogen atom, the unpaired electron spin means that a "normal" Zeeman effect is not observed.


How to automatic start recording and duplicating the sound wave in Audacity

Question: I am trying to record a sound wave through mic in audacity and generating its inverse simultaneously. and want to play them simultaneously, but have been unable to do that till now. Is there any way to do this?
Answer: I'm not 100% sure, but think you have to link the 2 channels/streams together after it's been recorded into Audacity. If i remember correctly you can do it when holding down control and just clicking the name at the start of the stream. Fairly sure that works with several recordings.
If it worked on a previous version then install it :)


Ubuntu inside VMware Player not connecting to host

Question: I am running a Ubuntu inside VMware player and it was working fine. But then I updated the ubuntu to latest version of it and from then it is not able to connect to the host i.e. Windows 7. Thus it is also not able to connect to internet. Can anyone tell how do I restore the connection with host. FYI - I have VMware Player network adapter configured in Bridged mode.
Comment: Strictly speaking I don't think this is a Stackoverflow kind of question.
Answer: Once you select the NAT, from the guest Ubuntu (12.04 for my case), choose the connection as "DHCP (Automatic)" NOT "DHCP (Automatic) addresses only".
This worked for me. I am running Vista 32 Host and Ubuntu 12.04 guest.
Answer: A bridged connection isn't necessary for a simple connection to the internet or the host but I'll assume that you choose a bridged connection because you need the guest to be a part of the same physical network that the host is. I haven't seen this particular problem but I can think of a few things to try.

Check the TCP/IP settings in both the host and the guest. They should have IP addresses within the same subnet, the same dns and default gateway.
Remove the virtual network adapter, shutdown the vm and add it again. If you have more than one network adapter, it's hard to tell which one it will "bridge" with.
I was having trouble with shared folders and the solution turned out to be to reinstall VMware tools. If libraries were updated then you may have broken VMware tools compatiblity with Ubuntu. Luckily the automated perl script that installs it can also build new binaries!
Answer: From my personal experience, check your Anti-Virus Firewall on your host (Windows 7) as well. AVG Internet Security for instance has a "Enable Virtual Machine Bridged networking", which if not enabled, does not allow your guest VM to access your host's network.
Answer: This worked for me.
When executed "ifconfig -a", the output did show an active virtual NIC, but the system could not connect to internet because it didn't have an IP address associated to the NIC (I had given a Bridged network to the guest Ubuntu).
To get it working, edit the file: /etc/network/interfaces
Add these lines:
<code># The primary network interface
auto [vNIC name as appeared on "ifconfig -a" output]
iface [vNIC name] inet dhcp
</code>
(remove the angular brackets)
Don't change anything of the loopback interface if you see one.
Save the file and reboot the system. That should do it.


Features - Should I go for big or numerous?

Question: I have worked on a few Drupal projects that used features.  I am usually perplexed by the way the way functionality is grouped.  I'm guessing that most of them were created as needed and by different developers that did not want to meddle with other people's features.  The outcome is usually a mess of different naming and grouping schemes.  Currently, I have the opportunity to create a site from scratch, and I want to start using a good methodology for creating my feature groups.  I am tending towards making a gigantic feature that contains everything, and only rebuilding one feature every time an update is needed.  What is good/bad about doing this.  Also, I feel more responsible while considering building several different features for each bit of functionality.  However, I am not sure how granular to go, or if this is begging for conflicts later.  How should I be approaching this issue?
Answer: It's all up to you. There are pros and cons to both and it depends on your use case.
Generally one would tend toward decoupled functionality with granular features instead of a giant feature. Especially if you wanted to potentially use these features on other sites.
Some information to help you out.
One big feature Pros:

It's quick and easy. If you're just using features to track database changes in code and
don't care about re usability, you can just stick everything in one
big feature.

One big feature Cons:

If you make one big feature, you can't re use it at all on another
site unless that site is almost exactly the same.

Decoupled features Pros:

You can re use features on other sites.
Your features are much more manageable, even it if it takes a bit
longer.
You can keep custom code which is directly related to the feature in
the features module, so you're keeping the feature + custom code in
one nice package.
This model fits in well with programming in general, taking big
problems, breaking them down, abstracting them, using dependencies,
etc. It will definitely improve your programming practising
separating your code logically like this.
Helps the way you think about Drupal components and how they mess
together.

Decoupled features Cons:

Overhead of organizing features structure. This will get easier as
time goes on and you get better.
Can be very hard to decide where to decouple, especially for newbies.
Answer:
How should I be approaching this issue?

Take a holiday
Come back when Drupal 8 is released
Use that.

;)
On a more serious note, I'd spend some more time learning core Drupal APIs and do as much as you can from an install profile using drush make and the smallest amount of contrib modules as you possibly can.


Finding perfect two terms Egyptian fraction

Question: If I have two unity fractions, like $\frac{1}{12} + \frac{1}{180}$, for instance. These two fractions can be re-writen as $\frac{1}{15} + \frac{1}{45}$ or even $\frac{1}{18} + \frac{1}{30}$, which satisfies the Egyptian Fraction concept of maximising the value of the smallest fraction. Is there a formula or an algorithm that when followed, one can find out all the possible equal pairs of any unity fraction pair?
Answer: This might be worth something.
Let $x=p/q, p<q.$
Then $1<q/p=[q/p]+z, z<1$, where [] is the greatest integer function or floor.
Now $[q/p]<q/p\implies p/q <1/[q/p]$, but we need to add additional fractions  $1/[p/q]$ to get $p/q$. This is not possible since the first term already exceeds the fraction. So we have to add 1 to the denominator as we go.
So $p/q=\frac{1}{1+[q/p]}+u/v$.
$u/v=p/q-\frac{1}{1+[q/p]}<1$ and the next term is $\frac{1}{1+[v/u]}$
$p/q=\frac{1}{1+[q/p]}+\frac{1}{1+[v/u]}+...$
This iterative process generates the Egyptian Fractions for a given number.
Answer: For a given rational number $\dfrac{c}{d}$, we wish to find all pairs of positive integers $(a,b)$ such that $$\dfrac{c}{d} = \dfrac{1}{a}+\dfrac{1}{b}.$$
We can manipulate the equation as follows: $$cab = da+db$$ $$cab - da-db = 0$$ $$c^2ab-cda-cdb = 0$$ $$c^2ab-cda-cdb+d^2 = d^2$$ $$(ca-d)(cb-d) = d^2.$$
Hence, $ca-d$ and $cb-d$ must be complementary factors of $d^2$. So the pairs of positive integers $(a,b)$ such that $\dfrac{c}{d} = \dfrac{1}{a}+\dfrac{1}{b}$ are all of the form $$(a,b) = \left(\dfrac{f_1+d}{c},\dfrac{f_2+d}{c}\right)$$ for all integers $f_1,f_2$ such that $d^2 = f_1f_2$ and both $\dfrac{f_1+d}{c}$ and $\dfrac{f_2+d}{c}$ are integers.


Unable to see complete scraped web page in Google Apps Script logs

Question: A few weeks ago I started learning Javascript and the Google Apps Script API, specifically in regard to spreadsheets. I have been trying to make a spreadsheet that fetches web pages and pulls stats about my friends for the game League of Legends. However, I have been running into a problem with the site I want to use, which is basically the only free LoL stats site that updates frequently. I'm not familiar at all with web development, but it seems when I try to access a page on lolking.net, for example http://www.lolking.net/summoner/na/60783 with Google's UrlFetchApp.fetch() it does not load the dynamic page. So instead of the final source, I get this which doesn't help me. Is there an easy way around this or would I simply have to use another website?
Comment: If you have found yourself here because you're having trouble scraping dynamic content with Google Apps Script, refer to [the canonical question](http://stackoverflow.com/questions/13788353/using-google-script-to-scrape-content-that-is-loaded-via-javascript/13790756#13790756) on the topic.
Answer: Thanks for thie info! Although it turns out I was mistaken. The UrlFetchApp was indeed returning the full source code, but I was using GAS's Logger to view the text. It seems the Logger has a length limit, so when I searched for the stats I wanted they weren't there simply because the source code got truncated. So, due to an oversight on my part, I never had a problem in the first place. For other people reading this question, in the end I have no idea how UrlFetchApp works with dynamic pages using clientside js (you'd probably want to talk to the poster below or post a new question).
Answer: You are getting fhe raw html page with clientside js included. That wont work from any system not just gas. You need to debug that page js and find where it does an ajax call to get the data you want.
Then do the same from your gas. Might not work if the call is authenticated etc.


Uninstalled apps still show up on "Apps installed on" in Google Play Store

Question: I already uninstalled the unwanted applications from my device, but they still show up  on "Apps installed on"  in my Google Play account.
Does it mean that the apps I got rid of are still stored in my phone?
Comment: It can take a little time for the web-based Play Store to see what is and isn't installed on your device. You can facilitate that by running the Play Store app on your device. That should kickstart the sync process between your device and the web.
Answer: In the Play store there is a 'installed' tab which as the name implies is of currently installed applications. The 'all' tab shows apps which have ever been installed on the device.
If you don't want a application to show up in this list, then from the phone open Play store, go into your My Apps and on the All tab you can click the circular remove icon to the right of the app will remove it from your Play account.
This is what it should look like:
Comment: One note about this: if you accidentally select more than one app, the X will be greyed out (or possibly missing).  This can inadvertently happen if you highlight one app, then try to remove a different one, IIRC.
Comment: I removed the app and it still says I have the app installed...
Answer: I have a Motorola Moto G, with Android 4.4.4 installed on it, so your version might be slightly different.
On your device go to 'Google Play', and go to the 'Menu' (the 3 horizontal bars on the top left of the screen), the Menu should pop-up from the left side of the screen. Select 'My Apps' and a new screen should pop-up, the 'My Apps' screen.
On the top you will see two choices, 'installed' & 'all'.  The first option is pretty self explanatory; the second choice lists ALL of the applications you have ever installed or uninstalled on your device.  If you go down the list you will see that the apps are listed and neatly separated by little rectangles. Notice that the uninstalled apps have a little 'x' in the top right corner of the rectangle. Tap it and the device will ask you if you want to remove it from the list.
That is how you remove it from the device. It'll be removed from the Googe Play site when the phone syncs with Google's servers.
Comment: This method works on my Samsung Galaxy sIII, too.
Answer: Sometimes it takes a while until the Play Store syncs with what's installed and what's not. You just have to wait and I haven't any method of making it sync faster.
Comment: You'll be waiting a while. I had uninstalled apps sitting in my acct for over a year.
Answer: Deleting cache and data of the Play store app solved the problem for me.
Answer: Go to Settings > Accounts > Google, and click the "Sync all" button at the bottom.
Answer: Try moving the app to the SD Card and uninstall it, if persist move it again to the phone and uninstall it, it works in my LG G3 when that happens
Comment: That will do nothing except waste time. Uninstalling a program is not supposed to remove it from the Play Store history.


Applet and JSF Integration - example

Question: Is there a tutorial or a simple applet example with JSF? How do I perform a request to a Managed Bean from an applet?
Comment: You can also do it via Applet-JavaScript as described here: [Applet-JavaScript](http://docs.oracle.com/javase/tutorial/deployment/applet/invokingJavaScriptFromApplet.html)
Answer: Don't use a JSF managed bean. It is not suitable for this job. Use a servlet or a webservice. To exchange data, use the session scope with an unique autogenerated key which you pass as parameter to the applet beforehand. This way the data will be available to JSF as well.
Answer: JSF (and hence managed beans) executes on the server to produce HTML; An applet executes on the client's machine - so you can't just pass a reference to a managed bean to an applet.
If you just need to pass a value from a managed bean to an Applet at start time, you can use the <param> sub-element of the  tag to pass this value.
If you need some kind of dynamic access to the managed bean, it's going to be a lot harder - basically, you'll need to build some kind of web service that's backed by the managed bean so that the applet can make http requests back to the server to get the values it needs.

Applet and JSF Integration - example


Travelling waves for nonlinear Schrödinger equation

Question: Consider the following nonlinear Schrödinger equation:
$$
-\Delta \Phi - i\frac{\partial \Phi}{\partial t} = f(|\Phi|^2)\Phi,
$$
where $\Delta$ is the Laplacian on $\mathbb{R}^n$, $f$ gives the nonlinearity (I am not specifying any conditions on $f$, since I want to make this a broad reference request; $f$ can be power-type or Gross-Pitaevskii type, or otherwise). I am looking for references for existence/non-existence of (super/sub)sonic travelling wave solutions of the above equation with null condition at infinity. By travelling wave solution, I mean a solution of the form $\Phi(x, t) = \varphi (x + ct)$, where $c \in \mathbb{R}^n$.
Answer: For the case of Gross--Pitaevskii type nonlinearities, you might look at the Annals paper of Maris (as well as references therein and thereof).  Here is an arXiv version: http://arxiv.org/abs/0903.0354
And, if you have access: http://annals.math.princeton.edu/wp-content/uploads/Maris.pdf


Remove all files created before a certain date

Question: I have a directory containing a high number of files (like logs for every day of the year).
I would like to remove all files created before let's say 22/11. How can I achieve that ? Must I use find then exec -rm? I'm using ksh.
Comment: The usual caveat is that Unix filesystems don't generally contain a record of when the file was *created* - only the times that  the inode and the content were *last modified* are available.
Answer: Using find is still the preferred way of deleting files. See http://mywiki.wooledge.org/UsingFind for more.
One way of doing this is to create a file with the time-stamp in it. e.g
touch -t 201311220000 /tmp/timestamp

Now delete the files GNUfind (assuming in the current directory) that match the time-stamp e.g:
find . -type f ! -newer /tmp/timestamp -delete

or non GNU find
find . -type f ! -newer /tmp/timestamp -exec rm {} \;

Comment: What about this ? Does it work ? find -type f -mtime +5 -exec rm -f {} \;
Comment: @user1058398 That will delete files older than 5 days from now.
Comment: @Avatar no because the `type -f` limits the action to the files only.
Comment: Does it also delete folder along with files? @val0x00ff
Answer: With GNU or some BSD finds:
find . ! -newermt 2013-11-22 ! -type d -delete

Note that it checks the last modification time of the files. On some BSDs, you can use -newerBt in place of -newermt to check the file's inode birth time if available instead.
Note that it will also delete the files created at 2013-11-22 00:00:00.0000000000 exactly, not that any clock is that precise anyway, but that could cause problems for files whose timestamp has been arbitrary set, such as with touch -d 2013-11-22T00:00:00 some-file (or touch -d 2013-11-22 with some touch implementation). You could always change it to ! -newermt '2013-11-21 23:59:59.999999999999' (GNU) or ! -newermt '2013-11-21 23:59:59' (BSDs, though that would miss the files last modified within the last second of 2013-11-21).
Answer: find /path/to/directory/ -mtime +<number of days> -name '<file name>' -exec rm -rf {} \;

example:
find /Netap_fileshare_backup/SQL/DB_backups/xeo/ -mtime +15 -name 'ORA_XEO*' -exec rm -rf {} \;

In this case it will remove all files that start whith "ORA_XEO" with more than 15 days.
Comment: Though better watch it with the `rm -rf`, the first command would remove everything contained in any directories that are older than those 15 days. (Also, why the parenthesis around `-name`?)
Comment: You're right, we dont need to put "\("  "\)".
Comment: but if we want to add a condition it can be usefull. for example if we want to remove all files that ends with ".jar" or ".cp", and start with "ex".

`example.jar` - it will be removed
`example.cp` - it will be removed

`example.tar` - it wont be removed
Comment: in this case we can use: `find /path/to/directory/ -mtime + \( -name '*.jar' -o -name '*.cp' \) -name 'ex*' -exec rm -rf {} \;`
Comment: That will remove some files from the __ rather than all files older than __ unless you run it exactly at midnight and it finishes within a second. With GNU `find` you should use the `-daystart` modifier to coerce the `-mtime` value to midnight.
Comment: yes thanks. In my case i run this with crontab at all sundays at midnight so i dont have problem with the hour.
but thanks anyway -daystart its a good tip to use!


How to make a touch screen device with android OS?

Question: I am planning to make a device which has a touch screen LCD. I have searched for solutions and i think if this device has android OS could be use for many applications. This device will be used for connecting to some DC and AC motor drivers. It will show numbers, play music and send data to a server. As price is critical, is using android suitable? If yes how to make a device with android os?
Comment: You can use an Android device via Bluetooth, or over the internet/intranet. I just ran across this, take a look at the Smart Phone Relay Control section, http://www.controlanything.com/
Answer: Without a lot of time and experience it will be hard to start from scratch. May I suggest buying a kit for this purpose. Something like those available here: http://www.liquidware.com/shop I'm sure there are many other companies that also supply them.
Answer: Making your own android device will not be cost competitive with buying one.
Making a custom adapter for an existing one (probably connecting via USB) is; but be sure that all of the safety systems (E-stop, etc) are in the adapter or even power supply, so that they continue working if the android device fails or mis-operates.
It may even make sense to run the real core of the system on the adapter, and just use the android tablet as a web-client user interface.


When do I use the 'plus-minus' sign when square rooting both sides of an equation? (example in main body).

Question:
Above is the image of an integration by substitution question that I was doing; the answer can only have a plus sign in front (if you were to differentiate the answer to check if it's correct). However, x needs to equal both positive and negative root -ln(u). Do I just forgo the plus minus sign and take the principal root (as I was told that you only need to take the principal root when rooting both sides; however, this is not true when solving quadratics, for example). Why do we only end up w/ on solution (at the very end)?
Comment: If I'm following your work correctly, then you're substituting for both $x$ and $dx$.  Both of these have $\pm$ (and it's the same sign), which should cancel out when they are multiplied.  This problem, however, is somewhat easier if you use $u=-x^2$ as your substitution.
Comment: Formatting tips [here](http://meta.math.stackexchange.com/questions/5020/mathjax-basic-tutorial-and-quick-reference).
Answer: As said in the comments, you may keep both branches of the $\pm$ when you substitute for both $x$ and $dx$. As both $dx$ and $x$ have the same sign (regardless of what branch you take), they result in the same sign on the answer.
However, an easier way of solving this problem is to write $u=-x^2$ and $du=-2x$. This gives:
$$4\int xe^{-x^2}dx=\frac{-4}{2}\int e^udu=\frac{-4}{2}e^u+C=-2e^{-x^2}+C$$


No Z hop in Dual extruder, print getting disturbed at retraction point

Question: I'm using a Lulzbot KITTAZ with V2 Dual extruder(0.5mm). When I'm printing anything, the front left side of the print is getting disturbed because whenever the tool head switches the action between the extruders, they stop at the front left point of the print. They are not performing the Z-hop and because they are hot they are disturbing the print at that point.
These are the settings that are currently set:

The print with the disturbance:

Sometimes the whole print is getting dragged to the extruders.
Answer: It appears as though you are using (or used) an old version of Cura. More recent releases allow you to insert G-code commands on changing the extruder. You could insert a Z-hop in these sections.
Extruder End G-code: First set the extruder in a relative mode, move up 2 mm, set absolute again:
G91
G1 Z2
G90

Extruder Start G-code: First set the extruder in a relative mode, move down 2 mm, set absolute again:
G91
G1 Z-2
G90

You could even do filament retractions to prevent oozing or stringing!
Note that this assumes both hotends are on the same carriage!

An alternative you could try is to use a print server that is able to inject G-code scripts, an example is OctoPrint:


I've read that assemblies manually placed inside Bin are also automatically referenced by

Question:
Q1
We can add assembly reference to a web project via Website --> Add Reference , and assembly will automatically be referenced by all pages in that web project.
But I've read somewhere that even if we simply copy ( thus we don't add it via Website --> Add Reference ) an assembly to the Bin directory of a web project, that it will still be automatically referenced by all pages in that project. But as far as I can tell, that is not the case?!

Q2
A)Deployed web site project also generates PrecompiledApp.config and website1_deploy.wdproy.
Should these two files also be copied to the server?

B) Deployed Web application project also generates WebApplication1.csproj and WebApplication1.csproj.user.

Should the two files also be copied to the server? If so, why?
I assume obj directory shouldn't be copied to the Web server?!

thanx
Comment: @Source - I think you should limit your posts to one question per post. It will make it easier to answer them.
Answer: Q1: "add reference" in a web site project means more than just copying the dll to the bin directly. It also means to place a dependency in app.config and to place a hint file which helps Visual Studio to find the dll from the source. This path is used by visual studio to copy the dll back to the bin directly (if somehow it gets removed) and to provide the "update reference" functionality. Having the dll registered in the app.config is essential for the runtime to compile your code using the right version of the dll.
Q2A:
website1_deploy.wdproy is not required. PrecompiledApp.config is. This file tells the runtime that the website was already precompiled and that the aspx files are just placeholders for IIS.
Q2B: you don't have to copy all those files. The .csproj file is just for visual studio to keep track of all files in your project. The runtime doesn't do anything with it. The .csproj.user file has your settings, again the runtime doesn't do anything with it. It doesn't even understand it. The obj folder is the temporary directory for the compiler. Also not needed after compilation.
Answer: Q1 - copying to bin is a runtime thing.  the Web Project is a develop-time thing.  They are related but not the same.
Answer: when you give a reference, it generally loads the reference in the config file, so if you add the required entry in config file and copy the dll in bin folder, it will be referenced directly without actually "add a reference"
you dont need to copy the wdproj file at all. its simply a deployment project which is helpful to build your releases.
you would need to copy the precompiled.config file to the deployed directory, though.


Generically Walk sObject Fields

Question: I've become quite comfortable with writing bulkified triggers that compare before and after values of specific fields. I've bumped into two cases where I'd like to do this generically for all fields. I don't want to depend on knowing the field's name and adding to the soql query and if-else block every time I add another field. Is there a way to generically walk a fields collection on an sObject? Is there a way to make sure that I've queried for all fields?
My two use cases:
(1) A trigger on product update that creates a diff email detailing all of the changes that were made (fieldName: beforeValue => afterValue).
(2) A trigger on opportunity that allows a very small subset of changes to Closed Won opportunities. So I have to walk all the fields and complain if any before values are different than their after values for fields that weren't specifically white listed.
Obviously, I could itemize all the fields in product and opportunity, build a massive soql for each and a massive if/else for each. But it would be a maintenance nightmare with adding and deleting custom fields. So I'm shopping for a smarter way to do it. Thanks in advance!
Answer: You need to combine schema describe (to know what fields are available) and dynamic apex (to work with fields that you may or may not know about when you write your code):
trigger OpportunityTrigger on Opportunity (after update) {
    Map<String, Schema.SObjectField> schemaFieldMap = Schema.SObjectType.Opportunity.fields.getMap();
    for(Opportunity newrec : Trigger.new)
    {
        Opportunity oldrec = Trigger.oldMap.get(newrec.Id);
        for(String fieldName : schemaFieldMap.keySet())
        {
            // put some filtering logic here - you don't need to compare all fields

            if(newRec.get(fieldName)!=oldRec.get(fieldName))
            {
                // note - fieldName isn't friendly - get the label from the schemaFieldMap
                newRec.addError(fieldName + ' was changed from ' + oldRec.get(fieldName) + ' to ' + newRec.get(fieldName));
                // we fail on first difference - if you want to report them all, you will need to handle this differently
                break;
            }
        }
    }
}

Answer: Salesforce has something called "Dynamic Apex"
It allows you to handle records as generic sObjects... or you can get the information for a specific object.
Examples: You can use Dynamic apex to get the "Describe" for an objectType (Account.getDescribe()) With that describe you can get all the fields for that object. You can then loop through those fields to put it in a string to use with database.query(querystring) to query all fields.
Another example for dynamic Apex is to "put" value of a field. If you know the 'field token' you can change the value of that field. This means your code is object/field agnostic and you're passing into the code the name for the field.
take a look here: http://www.salesforce.com/us/developer/docs/apexcode/index.htm
I'll dig through my code and see if I can find a good example. I'll post it here
Update
Quick Overview: Here I'm looping through contract records. i have fields that are in the format of "ProductFamily_Total_Recurring_Amount__c" -- what you don't see in this sample is that I built a list of my Product families by using dynamic apex to get the picklist values for the product family field on products.
So i build my field name by grabbing a value of a product family and turning the fieldName string into "MyProduct_Total_Recurring_Amount__c". I can then get the field that is' in "mFields" which is the map I built at the top. I could just as easily use that map to build a comma separate string of all the fields for database.query. Once I have the Field defined (f) I can replace the value by "putting" a new value. delegate.put(f,0.0); delegate is the contract record I'm currently updating.
  //Variables for Contract Loop
    String RecurringField = '_Total_Recuring_Amount__c';
    string NonRecurringField = '_Total_Non_Recurring_Amount__c';
    Decimal RecurringValue = 0.0;
    Decimal NonRecurringValue = 0.0;
    Object o = null; //Variable of field object that we can get the value of field name
    //Build map of all fields on Contract
    Map<String, Schema.SObjectField> mFields = new Contract().getSobjectType().getDescribe().fields.getMap();
    //Dynamic Apex variables.
    sObject delegate; //Contract active in loop
    Schema.SobjectField f; //Field in contract being updated
    string FieldName = null; //Field API name. Used to get Field from mFields (Field Map)
    //Loop through Contracts
    for(integer i=0; i<TheseContracts.size(); i++)
    {
      RecurringField = '_Total_Recurring_Amount__c'; //Standard Ending. FieldName format is *Product*_Total_Recurring_Amount__c
      NonRecurringField = '_Total_Non_Recurring_Amount__c';//Standard Ending. FieldName format is *Product*_Total_Non_Recurring_Amount__c
      delegate = TheseContracts[i]; //Set the current contract in loop to the delegate sObject

      //Default Exisiting Contract Amount fields to 0
      //Loop through all ProductFamily Possibilities and grab field if it exists
      for(integer p=0; p<ProductFamilies.size(); p++)
      {
        //Default Recurring Field
        system.debug('Getting Product Field Reference from: ' + ProductFamilies[p].Replace('_',' '));
        ThisProdFieldRef = lProdFieldRefs.get(ProductFamilies[p].Replace('_',' '));
        system.debug('Resulting Product Field Reference: ' + ThisProdFieldRef);
        //Build Recurring Field Name
        system.debug('Product Reference: ' + ThisProdFieldRef);
        if(ThisProdFieldRef != null){
          FieldName = ThisProdFieldRef.Contract_Recurring__c;
          system.debug('FieldName set from Custom Setting: ' + FieldName);
        }else{
          FieldName = ProductFamilies[p] + RecurringField; //Build API name for field
        }
        f = mFields.get(FieldName); //Get the field from map of fields based on API Name
        system.debug('Default field: ' + FieldName + ' Return from FieldMap: ' + f);
        //Check to see if F is null. Null means field does not exist
        if(f != null)
        {
          delegate.put(f, 0.0); //Set the value of the field to 0
        }
        //Default Non Recurring Field
        if(ThisProdFieldRef != null){
          FieldName = ThisProdFieldRef.Contract_Non_Recurring__c;
          system.debug('FieldName set from Custom Setting: ' + FieldName);
        }else{
          FieldName = ProductFamilies[p] + NonRecurringField; //Build API name for field
        }
        f = mFields.get(FieldName); //Get the field from map of fields based on API Name
        //Check to see if F is null. Null means field does not exist
        if(f != null)
        {
          delegate.put(f, 0.0); //Set the value of the field to 0
        }
      //End Prodct Family Loop
      }

Answer: As long as the sObject that you want to compare fields for is the one in your trigger you do not need to write any SOQL queries. Trigger.new and trigger.old already have all the fields on that sObject.
For the first use case the method you are looking for is:
Schema.SObjectType sObjectType
Map<String,Schema.Sobjectfield> fieldmap = sObjectType.getDescribe().fields.getMap()

The describe methods will return all the fields on an object but you want to make sure you are caching your results as describe calls are expensive and you don't want to do any more than necessary.
Your second use case doesn't require a trigger at all. What I would do is either
a) create a validation rule on the opportunity to enforce this logic. You would have to change if new user-editable fields are created but this is a fairly minimal amount of effort.
or b) create a 'locked' opportunity recordtype which opportunities are automatically covnerted to when they are 'closed/won' and create a page layout for that recordtype with everything read-only except the few fields people need to be able to edit.
EDIT: new answer below
If you do this with the JSON parser you do not have to use any describe calls and you do not have to walk through every field in the SObject.
public set<string> diff(Sobject obj, Sobject obj2)
{
    set<string> fieldDiff = new set<string>();

    map<string,object> objmap = (map<string,object>) Json.deserializeuntyped(JSON.serialize(obj));
    map<string,object> obj2map = (map<string,object>) Json.deserializeuntyped(JSON.serialize(obj2));
    objmap.remove('attributes');
    obj2map.remove('attributes');

    for(string key : objmap.keyset())
    {
        if( objmap.get(key) != obj2map.get(key)) fieldDiff.add(key);
    }

    return fieldDiff;
}

In a trigger you would still compare every field but if you got the Sobject from a SOQL query or were instantiating the object in apex you would only compare the fields that were returned from your query or the fields you set on the object.
Comment: Thanks for the schema code and answering my second question. I see how (b) could work--but I'm paranoid about blocking changes from data loaders or elsewhere. Because I'm only allowing changes to 3 fields, I think (a) would require checking that the other 97 fields haven't changed which is what I'm trying to avoid.
Comment: I wonder how the CPU cost of serialization & deserialization compares to describe calls.  Might be trading one limit for another
Comment: Neither of those are really necessary at this point. You can use the getPopulatedFieldsAsMap method for most use-cases where you'd want to iterate through all the sobject fields.
Answer: As of Summer 16' the most efficient way to traverse all the populated fields of an SObject is to use Map<String, Object> getPopulatedFieldsAsMap()
Map<String, Object> fieldsToValue = a.getPopulatedFieldsAsMap();

for (String fieldName : fieldsToValue.keySet()){
    System.debug('field name is ' + fieldName + ', value is ' +
        fieldsToValue.get(fieldName));
}

Release Notes
Comment: The problem with `getPopulatedFieldsAsMap` is that it ignores fields with null values, even if those fields were specifically queried by SOQL. SF doesn't seem to offer a way to differentiate between populated (as in field was included in query) and populated (as in non-null value)

Generically Walk sObject Fields


What changes when doing a higher level guild quest?

Question: I've been grinding on a guild quest for the Velocidrome to get more marital and the quest started at level 1 and now is at level 29. What exactly changes as the level goes up? I've notice the Velocidrome has gotten slightly harder, but does it give better rewards also?
Answer: The monsters in the guild quest will become harder as you clear them each time until the quest reaches LV 140.
LV1-30: Low Rank
LV31-85: High Rank
LV86-125: G Rank
LV126-140:  Super G Rank (need Special G3 Permit to take these on)
monsters at LV140 gets 300% base hp, if you are doing a dual monster guild quest, they are both at 270% as dual monster guild quests get's a -30%hp.
Finally, the reward will also become better, such as better relics and armor spheres at the end.
There's a lot of guides on how to get the most out of expeditions/guild quests if you google them.
Answer: From what I have done the reward and difficulty just seem to go up. Not sure if rewards change as all I get are velocidrome and prey stuff. Have gotten some abrasive at end also but no gear yet.


Too many notes for a bar

Question: Theory question. Looking at Villa-Lobos's Prelude no. 2 bar 9, there seems to be too many notes. The time signature is 2/4. See attached highlighted in yellow.
What am I missing?
Thanks
Answer: "Lazy" notation like this is very common in solo works. To be theoretically correct, there should be some sort of tuplet to squeeze the notes into the available space. In this case, that would mean making the notes one duration shorter and writing a 19:16 tuplet.
However, that would make it seem as if the composer intended that precise rhythmic figure, plus it would be a lot of visual clutter. This run is intended to be taken freely, and notating it as is communicates that. Sometimes you'll see composers opt for small notes, like grace notes, but this can imply that the notes should be played very quickly.
In short, experienced musicians can read the intent and don't get hung up in the accounting.
Answer: The E major chord is played for one beat, then the rest of the bar is played on the second beat.  Naturally, that second beat must be counted much more slowly than the first beat.
Here, in my opinion, is a great performance:
Comment: 'Counted much more slowly' - needs re-phrasing!
Comment: How about rubato? Zeit lassen?

Too many notes for a bar


What does it mean to "draw a line under something"?

Question: The intuitive answer to me would be to "emphasize" something. This explanation seems different from others I've seen, however, that say it means to "finish something". Help on this?
Comment: I don't find anything difficult to understand in the question, and don't know why it has been marked down. "different from other" is not standard, but seems perfectly clear to me.
Comment: The two different meanings for this are probably regional.
Answer: The idiom does have a different meaning from "emphasize".

draw a line under something
if you draw a line under something, it is finished and you do not think about it again: Let's draw a line under the whole episode and try to continue our work in a more positive frame of mind.
Comment: Now, I don't think it's either a "check" (I would say a "tick" in the UK) or crossing it out. The image for me is an account book, or perhaps a record of incidents. When one event is finished with you draw a line right across the page to mark the end of that and a fresh start.
Comment: I guess it's like doing a "check" on your checklist? or maybe cross it out?
Comment: Don't, however, confuse it with the similar phrase [draw the line (at something)](http://idioms.thefreedictionary.com/draw+the+line).  This means "to set a limit at something; to decide when a limit has been reached." *You can make as much noise as you want, but I draw the line at fighting. It's hard to keep young people under control, but you have to draw the line somewhere.*
Comment: Well done, Colin!
Comment: @ColinFine  I believe it's also a security thing, you draw a line through any blank space remaining on the page to prevent anyone adding something further. Similar to writing a cheque, so no one can add extra figures.
Answer: Think of it like writing down a column of figures to add. When it's time to finish, you "draw a line under it", do the arithmetic and move on to the next one.
Answer: It's an expression which originated as a term used by Accountants, in preparing the accounts -- especially the profit-and-loss account -- for any trading business.
Drawing a line under it is literally what the Accountant does, on the printed page, to rule-off the end of one trading period. At the end of the trading year it's traditional to draw a line across the page to mark the end of a trading period, and that marks the point up to which the trading accounts of the business are prepared for that period.
By literally drawing a line under the end of the year's trading, it physically separates one trading period from the next: the annual accounts are then prepared up to the marked point, with any later income or outgoings assigned to the following period.
Over time, it's become customary to use this expression in far wider contexts than simply business accounts, and the expression now denotes any situation where someone wishes to speak of making a fresh start.
In accountancy, each new annual trading period represented a fresh start for the business, whether the previous 12 months had been good or bad for it. This concept of ruling off events in the past and starting again is nowadays a form of common usage in a wide range of activities, many entirely unconnected to business finance.


How do I set a static IP for my iPad?

Question: I have an iPad v1 and need to plug in its IP to a program on my computer to test files.
The problem is every time I connect, the IP is reset and I have to enter a new IP.
Is there a way to have it permanently on one IP?
Answer: Settings --> WiFi --> select the network --> select Static and set the necessary values
Answer: In your router you should be able to statically assign an IP address for the iPad based on its MAC address.

How do I set a static IP for my iPad?


Double lies as sources of conflict in a single arc

Question: My protagonist lives with a deep lie that causes internal conflict and pain throughout the story but it basically cannot fuel any struggle to the external plot. This subconsciously motivates the character to leave a safe home and is somewhat prevalent later on.
I also introduced a flaw to the same protagonist (that is more like a wound but also can be seen as second lie) that causes external things to fail and makes things harder. They are both connected (they developed from the same event).
The flaw is overcome at the end of the second act, while the lie is overcome in the climax. Both the deep unconscious lie and the conscious flaw contribute to defeating the antagonist; the protagonist cannot accomplish that without learning both truths.
Can that double lie in one arc work? Or it is just too convoluted and confusing to the reader? I want that deep lie to convey the true theme—"moral imperative"—but it won't make protagonist fail in action. While the second flaw contributes to more direct tension perfectly, it's too weak to be the true core of the book.
Comment: Hi, I edited your post to clean up the grammar and make it easier to read.  Please check it and make sure I haven't changed anything that shouldn't be changed.  I wasn't sure about some of your wording so I left it as is.
Answer: Human beings are complex and flawed creatures. We do not each have just the one flaw. We have multiple failings, and multiple lies we tell ourselves. Now, for a story one has to simplify reality somewhat - focus only on those lies and flaws that are conductive to telling the story. But if you simplify the story to the point of each character just having the one flaw, you've simplified your characters to the point that they're flat and made of cardboard.
Take a simple story: Othello. Othello is jealous, that's part of the story. There's a lie he's been told - that's another part. And there's an insecurity in him about his position as a stranger - Iago can play on this insecurity to fuel Othello's jealousy. And even then, it takes a certain mindset to proceed from jealousy to murdering your wife.
Take a different simple story: Harry Potter. Harry isn't very smart. His inability to think before acting is repeatedly used by Voldemort, in addition to landing him into trouble without Voldemort's involvement. In addition to that, Harry is rash, rather lazy, and that's before we add into the mix the misunderstandings and the lies from other characters.
Complex characters are interesting characters. Don't think of your characters as checklists of traits - think of them as people, with multiple strengths and weaknesses.
Answer: I don't think it is too much. Many characters have "double lies", and in a way one can block the other. You say the deep lie won't make your MC fail in action, but that isn't true: You say the MC cannot defeat the antagonist without learning both truths: Thus continuing to believe the deep lie would indeed make the MC fail.
Sometimes, undoing a deep lie changes the person to let them undo other lies.
Answer: There are two theories of character. One, to which most people give lip service (at least) today, is the one that Galastel has expressed: characters, like people, are complex multidimensional constructs. This view of character seems to come from the modernist school of literary realism. It can, according to what I have read, but have not independently verified, be attributed to EM Forster.
The other, of which the critic James Wood may be the great contemporary expositor, holds that great characters are simpler than that. Rather than having all the shades and ambiguities of actual people, they are far simpler, exposing a single human trait. Their complexity comes not from the juxtaposition of multiple traits, but the thorough exposition of just one.
Some of the greatest characters in literature fit this model. Uriah Heap, for instance, or Quillip, or Little Nell, or Scrooge, or... well... any Dickens character you care to name. Captain Ahab. Gandalf. Lucy Pevensie. Emma Bovary. Becky Sharp. Jean Brodie. Jack Aubrey. Kurtz. Pinkey (either one). Hulk Hogan. Mr. Toad.
I am of the latter school. A story is neither a window nor a mirror but a lens. It brings one aspect of human life into sharp focus. It produce a sharper, clearer, simpler, more digestible, more exciting, more colorful, and more satisfying kind of experience than ordinary life provides, which is why we value stories in the first place, since the the experience of the murky realities of actual experience are available to us 24/7 if we want them.
And so a character is not as complex as a real person. Real people seldom act because their lives are too complicated and their spirits too weak and oppressed. They yearn for the shining stars of bold action, but almost never act like them. We want characters that are bolder, simpler, more vivid than ourselves; characters that are easy to grasp, to anticipate, to cheer for or to hate; characters, above all, who get on with things in a way normal people almost never do. Characters are not round, they are pointy.
So yes, two sources of conflict may indeed be too many. One source of conflict is plenty to drive a great story. And managing one convincingly, while maintaining tension throughout the story, and bringing it to a satisfactory climax and conclusion is difficult enough. Trying to do it with two may well prove impossible.
Don't confuse this, though, with having two sources of opposition. Characters with one problem often have multiple sources of opposition, because it takes multiple sources of opposition to force them into a situation where they have to finally confront their problem. No one wants to confront their problem. It wouldn't be much of a problem if they did. They have to be forced by circumstance into having to confront it. Trying to do that twice in one book is a tall order, and it simply is not necessary to create a fine compelling story.
My advice, therefore: pick one.
Answer: Different levels of complexity are necessary for different types of readers. If you're writing for kids, they'll only really keep track of one thing. But for young adults and above, I think this is appropriate. Readers are smart and they love to wrestle with more difficult things like that.
While you're writing, just go with it and don't think about it. Leave the analyzation for later. If it turns out that having two lies to overcome is too confusing, in your second draft you can revise it so that one takes center stage and the other fades into the background. Or perhaps you can remove one entirely. Just see how it plays out, and you'll know if it feels right or if you need to change it.


Can't access my site please help

Question: Today morning I saw that 3 plugins were asking for update then I updated 1 of them and my site got crashed now I can't access my site not even my wp admin panel please look into the site see if you can help me here is my site http://rtadvise.com
Answer: It's Loading fine for me both the site and the wp-admin login page.
If you are struggling with recently updated plugins,  Login to FTP and manually remove the plugins so you can gain access again.   You can then reinstall them one by one to narrow down the problem.
It might also be worth clearing your cookies and cache incase its a localised problem.
Comment: Thanks for the advise I deleted that plugin and then my website have started working BTW thanks again for your kind support
Answer: This happens from time to time with Wordpress plugins and often, you are not sure which plugin is the problem because you may have updated a number of plugins or a different plugin may conflict an updated plugin. My approach for resolving this sort of issue is as follows:

Log in through FTP
Go to the directory wp-content
Create a subdirectory called 'temp'
Move all the subdirectories from the plugins folder to 'temp'
Go back to your site and open it - it should work now unless the plugins were not the problem
Move the sub-directories in 'temp' back to 'plugins' one at a time and check the site (refresh each time ctrl+ F5)
When the site stops working, the last plugin moved back will be the problem.
Delete the plugin and move the remaining plugins back to the 'plugin' directory from 'temp'
Check the site - if it still works then you have identified and removed the issue.
Delete the empty 'temp' directory

This iterative approach has always worked for me. There may be better approaches and I will watch this post with interest in case someone else offers something better. I hope this helps you resolve your problem.
Comment: If you already know or suspect which plugin caused the problem, just move that one into temp in step 6 and if the site works again then you have resolved the problem.

Can't access my site please help