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March 24

matrix

101.222.245.26 (talk) 17:21, 24 March 2014 (UTC)i need to write get a code in c without using any functns ,i have just arrays and pointers and stdio.h.the test case is for 2*2,3*3,4*4 matrix.what i wrote is just giving me for 2*2 and 3*3 .any suggestions.

What exactly is your code supposed to do ? Read in a matrix from a file and print it out ? If you are off by 1, that may be an error due to C starting arrays at 0 instead of 1. So, if you are reading in a 3x3 array and then printing out elements [1,1]-[3,3] instead of [0,0]-[2,2], that would cause a similar problem. You can show your code here for more answers, if this advise doesn't help. StuRat (talk) 17:40, 24 March 2014 (UTC)

"i need to write get a code in c without using any functions". Tell us why you "need to write" and why you cannot "using any functions". If you are writing in C language, then writing C functions is a natural way to program. Not writing any functions is highly unnatural. Anyway, what you need are algorithmn for matrices which you can find in math textbooks at college or university levels. The actual computation language is just a tool to use for computations. 202.177.218.59 (talk) 01:27, 25 March 2014 (UTC)

It's hard to say exactly what our OP is asking here - but I presume "without using any functns" means "without using any external library functions"...or something like that - otherwise you could simply find a linear algebra package someplace and solve the problem with a single function call. Also, I'm a little concerned that this is probably a homework question, it's hard to imagine a non-homework situation where forbidding the use of an external library would make sense - and we're not allowed to help you do your homework. But in any case, there is simply no way we can help to debug this code without seeing it. SteveBaker (talk) 16:41, 25 March 2014 (UTC)

StuRat, +1.

so sorry,actually i needed to print it in spiral form which i couldnot save in question.my code is here.

#include <stdio.h>
int main()
{
    int m,n;
	int p,q,a[10][10];
	scanf("%d%d",&m,&n);
	for(p=0;p<m;p++)
	{
		for(q=0;q<n;q++)
		{
			scanf("%d%d",&a[p][q]);
		}
	
	}
    int i, k = 0, l = 0;
 
    /*  k - starting row index
        m - ending row index
        l - starting column index
        n - ending column index
        i - iterator
    */
 
    while (k < m && l < n)
    {
        /* Print the first row from the remaining rows */
        for (i = l; i < n; ++i)
        {
            printf("%d ", a[k][i]);
        }
        k++;
 
        /* Print the last column from the remaining columns */
        for (i = k; i < m; ++i)
        {
            printf("%d ", a[i][n-1]);
        }
        n--;
 
        /* Print the last row from the remaining rows */
        if ( k < m)
        {
            for (i = n-1; i >= l; --i)
            {
                printf("%d ", a[m-1][i]);
            }
            m--;
        }
 
        /* Print the first column from the remaining columns */
        if (l < n)
        {
            for (i = m-1; i >= k; --i)
            {
                printf("%d ", a[i][l]);
            }
            l++;    
        }        
    }
   
 
    return 0;
}

101.222.245.45 (talk) 18:32, 26 March 2014 (UTC)

I do see lots of 1's that should probably be 0's, since C arrays start at 0. I suggest you manually write out which array elements should contain which value, and go through the program manually, keeping track of each value for each variable as you go. This will help you understand what your program is doing better.

Also, just hard-code a printout of the array, as a[0][0],a[0][1],a[0][2] on one line, then a[1][0],a[1][1],a[1][2] on the next line, and a[2][0],a[2][1],a[2][2] on the last line, and avoid any use of loops, etc., which could cause confusion. Once you know what's in your array it will be a lot easier to debug the rest of your program. StuRat (talk) 16:24, 27 March 2014 (UTC)

Also keep in mind that if you declare an array, say, float matrix[4][4], a valid index is between 0 and 3 because the bracketed numbers are the number of rows/columns, not the last valid index. (This hit me when I was new to C++, too.)

Trying to access, say, matrix[4][4] is illegal. On top of that, C doesn't check if your index is invalid, but read/write from/to the address anyway. This will usually corrupt other variables.

(Unfortunately, the data corruption article doesn't talk much about bugs causing data corruption; its primary concern is malfunctioning or damaged storage hardware. Memory safety is more relevant here.)

BTW (and by BTW I mean something completely different), Inaccessible boot device is at least a questionable redirect IMO, and the target doesn't touch the issue in the slightest. I think it must go or be retargeted, but someone with more experience in the WP deletion processes should look into it. - ¡Ouch! (^{hurt me} / _{more pain}) 07:54, 26 March 2014 (UTC)

March 25

Does makeup confuse modern facial recognition systems?

Can they automatically tell sunken eyes from eyeshadowed eyes, for instance? Or do our face wrinkles have "fingerprints" that foundation might obscure? Any other such stuff? InedibleHulk (talk) 03:26, March 25, 2014 (UTC)

I believe that most systems build a model of the face and use distances between features. There is speculation in a recent new scientist that avant-guarde high-contrast makeup could fool facial recognition by making it hard to detect the measurement points, though normal makeup probably wouldn't help. -- Q Chris (talk) 08:48, 25 March 2014 (UTC)

There are a variety of different approaches out there - some use video footage rather than a single still image. The varying viewpoint allows them to extract three-dimensional information. Others use two cameras to capture a stereo view for the same reason - or employ "structured light" (kinda like the "Kinect" gadget) to achieve the same basic result. Knowing the three-dimensional shape of the face makes it much harder to disguise with makeup. So I suspect that these clever makup tricks could confuse simpler systems, but if large numbers of people started employing these tricks, the technology could easily evolve to fix that. Of course wearing big sunglasses and a false moustache works pretty well too! You might be interested in our Eigenface and Active shape model articles that cover some of the techniques. SteveBaker (talk) 14:15, 25 March 2014 (UTC)

Thanks, I'd have never thought to find those articles. I'm mainly thinking of 2D "#nomakeupselfies". They seem otherwise pointless. Of course, planking was also rather pointless, and generally harmless. Maybe I'm paranoid. InedibleHulk (talk) 16:50, March 25, 2014 (UTC)

You also might be able to confuse them by being dark skinned. Matt Deres (talk) 11:13, 27 March 2014 (UTC)

Cracked told me about the HP ones doing that. May not prove racism, but it does suggest they don't hire black testers. InedibleHulk (talk) 03:04, March 28, 2014 (UTC)

How are commands entered into a Game Boy Advance running UNIX?

How are commands entered at the shell prompt of a Game Boy Advance running UNIX as shown here? 20.137.2.50 (talk) 17:20, 25 March 2014 (UTC)

From the page you linked: "gbaunix does not have an input mechanism currently. You can only execute a canned sequence of UNIX shell commands. The sequence must be specified at compile-time as an array of strings in gba/gba_kbd.h in the source. While UNIX is running, pressing the START button feeds the next command line into the TTY's input buffer." - Cucumber Mike (talk) 17:25, 25 March 2014 (UTC)

Thanks. You don't happen to see there how one actually gets one's gbaunix physically onto a real cartridge, do you? 20.137.2.50 (talk) 18:01, 25 March 2014 (UTC)

Nevermind, I assume it would be using a Flash Cartridge. 20.137.2.50 (talk) 18:14, 25 March 2014 (UTC)

No MX or A records for nauta.cu

If I were to receive the following message on an email returned to me, could the casue be the monthly data limit was reached? Is some other cause likely?

---

Sorry, we were unable to deliver your message to the following address.

<name redacted@nauta.cu>: No MX or A records for nauta.cu

---

Thanks. μηδείς (talk) 19:26, 25 March 2014 (UTC)

If you're talking about the data limit for the entire nauta.cu domain, then there's a remote chance if the mail server provider intentionally removes the MX or A records presuming they have that control when the quota runs out to reduce the amount of traffic they receive. Since they seem to also control the nameservers, they probably do in this case. I've never actually heard of anyone doing this, but I'm not that familiar with mail server hosting practices, even less in Cuba.

There's no chance this could happen for simply one email account in the domain under any resonable circumstances regardless of whether it exceeded the quote limit, your email tripped some censorship filter or whatever. More specifically, some mailserver involved (I don't know from what you quoted what mailserver sent this although I would expect it to be the mail server you used or another controlled by the same company) would need to be seriously (most likely intentionally) misconfigured to do this as they are basically lying about the cause of the failure and in a way that makes no sense.

The more likely explaination is some temporary misconfiguration or mistake. When I did a nslookup just now [1], I did find multiple MX records (no A but that may be normal, it sounds like the domain is only used for email). So I would try the email right now. If it still doesn't work give it another 3 days or so (you can probably try every day or less without risk) for the intermediate mail server DNS caching to catch up with the DNS update.

If it still doesn't work after 3 days and there is still a MX record then there may be a problem with some mail server involved, so try using a different service. (The other possibility is the name server keeps adding and removing the MX record and you mail server gets it at the wrong time and you get it at the right time. I guess it's also possible the name server is refusing to provide an MX record to whichever name server is requesting it for your mail server.)

Nil Einne (talk) 21:18, 25 March 2014 (UTC)

Thanks. What has been going on from my end is a user at that domain has been requesting files of 1-2 MB on average, but requested one last night that I did not realize was 27MB. According to press reports, these files cost about $1 per MB, while the average monthly income is $20. I fear what I have sent may cost several month's wages. I am wondering if I can compensate from my ownend, and hoping there's noting worse I have done than what I imagine. μηδείς (talk) 21:59, 25 March 2014 (UTC)

I have been able to send two messages but received no response, and gotten two inquiries aking if there's a problem, but no response to me answer to those inquiries. μηδείς (talk) 13:44, 26 March 2014 (UTC)

So far this seems to be some sort of problem with Yahoo. For two days prior Yahoo wouldn't upload attachments even bore you had the email addressed or tried sending them. Using a new gmail account I have been able to get through to the nauta.cu address. I just sent another text file through yahoo which hasn't come back yet. (I'd use gmail exclusively, but the format seems harder to read.) I was wondering if there was any reporting on this in the media. I remember when it became possible to make direct phone calls a decade ago. They cost an enormous amount of money (like $5/min) and where of terrible quality, with the US carriers pocketing a good amount of the money. Any links to news on the relevant issues would be helpful. Thanks. μηδείς (talk) 19:07, 26 March 2014 (UTC)

To follow up on this, in case anyone else is in the same predicament, I have not had problems with gmail going through for the last two days, although at first there was a "box is full" message. Yahoo will not go through at all at this point, whether it's a short text email or has an attachment, I still get the original "No MX or A Records" error message. μηδείς (talk) 04:20, 29 March 2014 (UTC)

March 26

nexus features

i have a new nexus 5 phone which shows it has 25 hidden features which i cant find in specification manual or anywhere else.any suggestion or redirecting link .thanks in advance.101.222.240.1 (talk) 17:15, 26 March 2014 (UTC)

I tried using google to search for "nexus 5 hidden features" and the first two hits were 25 hidden nexus 5 features and 25 tips for the google nexus.-gadfium 03:13, 27 March 2014 (UTC)

What was the processing power of Folding@Home?

Are there any statistics to the total peak processing power of the Folding@Home program? Along with all the desktop CPUs and GPUs, there must have been tens of thousands of Playstation3 consoles contributing (before it was discontinued on that platform). --209.203.125.162 (talk) 17:33, 26 March 2014 (UTC)

Current statistics are at Folding @ Home Client Statistics, and are explained elsewhere, including "High Performance FAQs". Nimur (talk) 21:43, 26 March 2014 (UTC)

Image conversion

In Windows 8, what application can convert a DesignCAD file into a JPEG image? Thanks in advance! 24.5.122.13 (talk) 22:45, 26 March 2014 (UTC)

If you can't find something to do a direct conversion, you can always do a screen grab and paste it into MS Paint. Of course, you will have some cropping to do and you are limited to the resolution of your screen (let me know if you need help with any of this). StuRat (talk) 16:12, 27 March 2014 (UTC)

It might depend on the exact type of file you have, but as far as I can see the only programs that can open native DesignCAD files are various versions of DesignCAD itself. Looie496 (talk) 18:46, 27 March 2014 (UTC)

In that case, can it save in some other common format, like GIF, TIFF, or PNG ? If so, then another program can convert that to a JPEG. StuRat (talk) 03:06, 28 March 2014 (UTC)

No it can't -- it can only save in various DesignCAD formats. So I guess I'll either have to copy-paste the image into some other application, or else print it out and scan it back in as a last resort. :-( Is it possible to do either of these and maintain a resolution of at least 300 dpi? 24.5.122.13 (talk) 04:45, 28 March 2014 (UTC)

I'd go with a screen capture because it is lossless. If you need higher resolutions, maybe you can capture different parts, all at the same resolution, and assemble them using Paint? I've done that with some WP articles; it does get a bit more difficult with 2-dimensional pictures (i.e. cases where the image is both higher and wider than the window). 300dpi translates into ~2500x3300 pixels, so it could be as few as 2x3 images, depending on the resolution.

Printing to a file is another approach. There are tools which can convert HPGL instructions to bitmaps. PostScript might be another option. These take more work to set up, but are probably the way to go if you want to convert many files. - ¡Ouch! (^{hurt me} / _{more pain}) 07:04, 28 March 2014 (UTC)

That ~2500x3300 pixels corresponds with the print resolution on an 8.5x11 inch sheet of paper (although you can't actually print right to the edge so will get a bit fewer pixels than that). However, for the screen capture resolution, you can get as many DPI as you need, depending on the zoom level on the object, when you do the screen grab. There, however, the total resolution is limited to that of the screen, although again there's often junk at the edges that needs to be trimmed off (unless DesignCAD has an option that displays the image alone in full screen mode). If we assume a max screen resolution of 1720x1080, this gives us a rather small printable image at 300 DPI, around 5.7x3.6 inches. StuRat (talk) 13:50, 28 March 2014 (UTC)

Can you definitely not use DesignCad to save your file as a jpg (I'm assuming you have access to the DesignCAD software)? This suggests that you can, although I can't test it myself. --Kateshortforbob _talk 12:15, 28 March 2014 (UTC)

This applies to DesignCAD v. 20 -- I only have v. 12 (which I first used in high school, and which miraculously still works on Windows 8). 24.5.122.13 (talk) 08:05, 29 March 2014 (UTC)

Oh, rats. Never mind then :) --Kateshortforbob _talk 00:33, 30 March 2014 (UTC)

March 27

Sharepont Text Editor

When I click on a .txt file in Sharepoint, and select "Edit", it opens the file in Notepad, even though I've got Notepad++ set as the default application for text files. Can I change this behaviour? Rojomoke (talk) 10:56, 27 March 2014 (UTC)

As I understand it, you need to change the file association in your browser. Hopefully the information at http://weblogs.asp.net/bsimser/archive/2005/07/18/419824.aspx will be helpful to you. Looie496 (talk) 18:09, 27 March 2014 (UTC)

Google searching advice

Checked their help pages and I didn't see my answer. How do I tell Google to return exactly the word that I want, and ignore alternate spellings and versions of the word? It's nice that they try to find related concepts (go to https://www.google.com/#q=searches and it gives you results for "searching," "search," etc., or https://www.google.com/#q=jeremy+zits+%22top+shelf%22, looking for a specific day's comic strip, and it gives you results for pimples and acne), but I'm trying to understand the frequency of spelling variants. Right now, a search for <word> gives me pages with <word> and pages with <words>. I know I can do <word -words>, but that skews things because it gets rid of pages with <words> whether or not <word> is present. I'd like it to find results with <word> and totally ignore <words>, giving it no more significance than it gives <gobbledygook>. Is this even possible? 2001:18E8:2:1020:3C53:B749:C596:5ACE (talk) 16:00, 27 March 2014 (UTC)

Did you try searching for "word" ? I think in quotes it does what you want. For example, "Ruszians" does not return "Russians" at least in the results google throws at me. Keep in mind that google shows different results for different people, but I dont think this personal ranking changes the set of results, just the order. Brusegadi (talk) 04:10, 28 March 2014 (UTC)

Windows 7 Installer missing .msi file

I tried to re-install my HP Photosmart C6380 All-In-one printer on Windows 7 Home Premium, now my installation process says; it cannot continue because it cannot find the .msi file in order to continue the installation. I have the HP printer install disk that came with the printer when I purchased it. I have tried the Driver-Software download from HP website, but it still comes up with "Error 1706". How can I get or reinstall the "Windows Installer" or update the latest version without a Hugh cost? I am looking for a safe website that may have a free download of "windows Installer" for this problem and a fix for Error message 1706. I appreciate any help and advise anyone may have. Thank you Polkateer (talk) 19:38, 27 March 2014 (UTC)

Been there. The HP installer extracts to a temp folder in appdata. Sometimes it thinks it extracted the files, but did not copy all of them to the folder. To fix this:

1. Note the error message— it should give the full path; it will be something like C:\Users\myname\AppData\Local\Temp\another folder
2. Unzip the installer to a known folder; use 7-Zip if you don't have an archive tool already
3. Copy the extracted files, including subfolders to the appdata folder; if you can't see the appdata folder, just type it on the address bar
4. Run the installer again

--  Gadget850 ^talk 20:17, 27 March 2014 (UTC)

Is functional programming difficult? Or is it Haskell?

What makes people say that Haskell would blow up your mind? Or that it needs a totally different perspective? Is it difficult? Is functional programming difficult? When I think about functional programming I think about Excel, which, for me is kind of easy to grasp and implement and realize what will happen. At least this functional programming language seems easier than OO programming languages, that some people seem to have huge problems with. OsmanRF34 (talk) 20:08, 27 March 2014 (UTC)

Functional programming really isn't at all like Excel. Excel is, paradigmatically, just another procedural, stateful system like C or Java. Purely functional languages like Haskell are a fairly different paradigm than say python, but I don't know that there's really evidence that someone who wasn't familiar with any programming language would find Haskell intrinsically more difficult than say Python. There is a jump from procedural to functional, but it's not a chasm. Someone whose experience was with Lisp, with mathematical notation, or perhaps a logic language like Prolog may well find Haskell easier to pick up than Java - that's a characteristic of their familiarity with the general concepts, not one language being "easier" than the other. There's a lot more to Haskell than just functional programming, including lazy evaluation and a rich type system, which don't have analogues in say Excel, and so that's more material someone learning Haskell would have to grok. -- Finlay McWalterჷTalk 20:47, 27 March 2014 (UTC)

• When I said Excel is a functional language, I meant the spreadsheet, used for something more than just calculations, not that VBA for appliations scripting language within Excel. Each cell has a function in it, which has no collateral effects. The program 'executes' as cell change, and there is no pre-established order, the functions determine what will calculated next. And you can select items with with IF and HLOOKUP. OsmanRF34 (talk) 16:19, 28 March 2014 (UTC)

If I might argue by analogy: if you already play the guitar, it's probably easier for you to learn the violin than the piano. That doesn't mean the violin is actually easier than the piano, just that it's a bit more like the guitar. I imagine a xylophone player would find the piano somewhat easier to learn than the violin, for the same reason. It's still a jump from the guitar to the violin (much more than the guitar to the banjo or mandolin), or from the xylophone to the piano. The real underlying skill, music itself, is portable - there's plenty of people who can play violin and piano, and who found learning one improved their playing of the other. -- Finlay McWalterჷTalk 21:01, 27 March 2014 (UTC)

My background is mathematics, and I found Haskell extraordinarily easy to pick up. My first language was BCPL, and over the years I've written in many other procedural languages, but they do not really prepare you for the joy of finally learning a language that is so close to pure mathematics and logic. For the sort of work that I do - basically, applied mathematics - functional programming is a very natural approach. In my experience it isn't difficult to learn functional programming in Haskell or other similar languages. However, it isn't suitable for every purpose. Of course it's Turing complete, but different languages make different tasks easier or more difficult. For example, if you're working with databases, I'd encourage you to select a language that has been developed with that task in mind. For sheer enjoyment of learning and coding, though, and for the pleasure of a language where the link between the mathematics and the code is instantly clear, nothing beats Haskell: it soars while other languages plod. RomanSpa (talk) 21:30, 27 March 2014 (UTC)

I don't know that functional programming is more difficult than OO programming, but it requires mastery of different concepts. Instead of simple iteration, there are map and fold functions that ultimately depend on recursion, and many people find recursion a challenge to understand well. Of course, polymorphism, inheritance and design patterns in OO languages aren't easy either. Haskell is a particularly difficult because (1) it is a pure functional language with no state variables, (2) lazy evaluation is something to get used to and (3) it is a language designed by mathematicians, for mathematicians, and the basic concepts reflect that heritage. Monads and applicative functors really are the same concepts as those in category theory and I understood Haskell a lot better after I had learned some category theory. Learning functional programming can be easier in the context of a multi-paradigm language, such as Scala, Lisp, or Perl. --Mark viking (talk) 21:43, 27 March 2014 (UTC)

On the other hand, I probably understood category theory better after mastering monads! RomanSpa (talk) 23:13, 27 March 2014 (UTC)

(ec) SQL is a functional language. Google queries are a functional language. You simple state "I want such and such results, now you do the thinking". That makes it much more simple than if you have to spell out what the computer should do. In reality, though, if you need complicated things you will need to think about what the computer will make of it. So while your code may look simple, you have to think at two different levels at the same time. Joepnl (talk) 21:51, 27 March 2014 (UTC)

Haskell has a steep learning curve because it requires the programmer to deal with much more mathematical abstraction than most mainstream languages do. Its type system (including the notorious monads) is a fairly big hurdle in its own right. Its functional purity means you can't (without technical tricks) insert "print" statements for debugging in non-I/O code. You have to learn to organize your programs to have an I/O shell around a functional core. The immutability of data (mutable types exist, but should be considered an advanced feature) means you have to learn about functional data structures instead of traditional imperative ones (for example, AVL trees instead of hash tables).

Lazy evaluation has its own mind-bending consequences such as the ability to operate on infinite data structures. Writing performant code requires knowledge of the library ecosystem at a level not obvious from a bare understanding of the language, in addition to getting used to fixing lazy evaluation snags such as space leaks. Overall though I think it is very much worth learning and using, if for no other reason than it will drastically expand your understanding of programming. The book "Learn you a Haskell" is a good online tutorial, and wikibooks:Haskell has good coverage of some more advanced topics. In particular, b:Haskell/Category theory is a very readable explanation of how categories are relevant to Haskell, and their relationship to Haskell's monads, functors, and so on. 70.36.142.114 (talk) 22:40, 28 March 2014 (UTC)

I would also recommend "Learn You a Haskell for Great Good!" by Miran Lipovača. It's a very readable book, and a good starting point. RomanSpa (talk) 18:45, 29 March 2014 (UTC)

Yes, that is the book I mentioned. It's online at learnyouahaskell.com . 70.36.142.114 (talk) 23:04, 29 March 2014 (UTC)

Note also: Turing completeness is not a requirement for FPL's, and there is an argument that Turing completeness in programming languages is over-rated. See the article total functional programming. 70.36.142.114 (talk) 02:12, 29 March 2014 (UTC)

Windows search as you type

In Windows, you can open a list of files in Windows/File Explorer, then start typing and the focus will jump to the file name you are typing. What is the official name for this? --  Gadget850 ^talk 20:26, 27 March 2014 (UTC)

Desktop search? Incremental search? Microsoft product literature calls their feature the "Search charm." Nimur (talk) 23:38, 27 March 2014 (UTC)

No. This is not from any search box. It is simply opening Windows Explorer and start typing. I need to change the speed for one user. --  Gadget850 ^talk 11:42, 29 March 2014 (UTC)

March 28

CrystalDiskMark - what is QD?

CrystalDiskMark (http://crystalmark.info/?lang=en) is a program to benchmark drive speed. It tests:

• sequential
• 512K
• 4K (QD=1)
• 4K QD32 (QD=32)

What is "QD"? Bubba73 ^{You talkin' to me?} 02:52, 28 March 2014 (UTC)

QD is queue depth, the number of 4K requests in the queue. Because of the way an OS might cluster IO requests, QD=1 may give different throughput than QD=32. In particular, if there are multiple requests in the queue, the OS may try to optimize head seeks to speed things up, see, for example, elevator algorithm. --Mark viking (talk) 03:19, 28 March 2014 (UTC)

Thanks. I was testing on an SSD and it made a big difference:

          Sequential Read :   450.777 MB/s
         Sequential Write :   417.344 MB/s
        Random Read 512KB :   418.733 MB/s
       Random Write 512KB :   384.495 MB/s
   Random Read 4KB (QD=1) :    25.948 MB/s [  6335.1 IOPS]
  Random Write 4KB (QD=1) :    89.090 MB/s [ 21750.4 IOPS]
  Random Read 4KB (QD=32) :   246.661 MB/s [ 60219.9 IOPS]
 Random Write 4KB (QD=32) :   228.627 MB/s [ 55817.2 IOPS]

Bubba73 ^{You talkin' to me?} 03:33, 28 March 2014 (UTC)

gateways

Hello,

I was surprised today when my motorola changed to an Arris device... I read about this and it seems like ISPs have the power to upgrade your firmware. My question is, how much power does an ISP have over my gateway. Note that I do not rent this gateway, I bought it thinking that I would be able to control stuff like this... If I am concerned about stuff like this, would buying a separate modem and dedicated router do the trick? Thanks! Brusegadi (talk) 03:58, 28 March 2014 (UTC)

Ubuntu + SSH

I recently decided to switch to key-based authentication for SSH on my network. After dedicating a few hours to figure out how it worked, it seemed simple enough. However I hit a snag when I tried running ssh-add on my Ubuntu 13.10 install. While I could get it to work, I could never get it to retain my key/passphrase information across reboots.

After combing through some internet forums, I found various "solutions" but none of them really seemed to address the problem. Adding identity files in my ~/.ssh/config is not a solution in my mind (it makes key management messy and does not scale well). No shell scripts I found will work either as all my keys are protected by passphrases. I suppose if I must, I will remake keys with no passphrases, but I would prefer not to.

What is causing this issue and how can I get the ssh-agent to work properly and retain my keys across reboots?

I have some clues that it might have something to do with Unity's keyring implementation, but I do not know how that works. I will happily disable it if possible though.

Thanks in advance. -Amordea (talk) 11:43, 28 March 2014 (UTC)

Nevermind. After a few more complications with Unity, I've just decided the Unity interface is not worth mucking with. I will just use a different distribution for this project. -Amordea (talk) 15:29, 28 March 2014 (UTC)

It's not supposed to retain your passphrase across reboots. It keeps the secret key in RAM for security (don't want it on the hard drive where someone could recover it). So when you reboot, you have to type the passphrase again. That is intentional. Maybe what you really want is a hardware security token, if you never want to re-enter your passphrase. You should probably use a passphrase anyway though, per the principle of two-factor authentication. 70.36.142.114 (talk) 22:27, 28 March 2014 (UTC)

It can if you place it in your key-ring. This causes the passphrase to be encrypted and stored on disk. It gets decrypted upon login. I have been able to do this in Ubuntu using Unity, but I have not sshd anywhere in ~ 6 months... Brusegadi (talk) 23:27, 28 March 2014 (UTC)

On my Lubuntu install, it does. Which I actually thought rather strange since ssh-add doesn't work if I don't input the passphrase. I don't actually mind typing the passphrase each time I log in. What I want to avoid is having to type ssh -i path/keyname user@host every time, when I should only have to type ssh user@host. A few extra keyclicks, I know, my poor fingers! But I don't really see what the point of the ssh-agent is if it only works during a single login session. Or maybe there is a thing I'm still not understanding about the ssh-agent? I'd welcome some more insight on SSH best practices if anyone's wanting to share them. -Amordea (talk) 11:05, 29 March 2014 (UTC)

real time scatterplot utility

Dear Computing desk, I'm in the process of writing a fitting program that dumps its output into a CSV every X number of iterations. Does anyone have any recommendations for a program that could replot the output in real time? Right now I'm just looking at the RMSD calculated after every step, but I'd much rather have a graph that would automatically refresh after every refinement step. Preferably something X11 friendly, but I'm not really picky. It's not at all a crucial feature, more decorative than anything. Thanks, (+)H₃N-Protein\Chemist-CO₂(-) 13:52, 28 March 2014 (UTC)

I can think of 3 ways to run the plot program periodically:

1) The program which saves the data can also kick off a run of the plotting program, after each file save. This is likely the best option. A system call from the main program can probably accomplish this.

2) The plotting program remains running constantly, and can monitor the file, and plot more data as it arrives. This is a bit trickier, as you now have two programs trying to access the same file at the same time, and might be more CPU intensive, as you have to keep checking for updates to the file. It might work better to add each iteration of data as a new file with a timestamp on it, then the plotting program can detect any new file in that directory and plot it.

3) The plotting program can just have a time delay in it and replot at those intervals. You might still run into file contention problems, though, and you might sometimes get hiccups where the same data is plotted twice or you skip plotting one iteration, making the results look rather haphazard. Weather maps in motion often have this jumpy look. StuRat (talk) 14:32, 28 March 2014 (UTC)

Yes, number 2 is how I was thinking of doing it. Possibly number 3. I was mainly looking for recommendations for plotting programs. (+)H₃N-Protein\Chemist-CO₂(-) 20:11, 28 March 2014 (UTC)

@Protein Chemist: Depending on your scripting skillz and time available, I'm pretty sure Gnuplot would work. Definitely free/X11 friendly, not necessarily user friendly :) This would work with Stu's option 1) and 3) I think, not sure about 2), but probably... SemanticMantis (talk) 20:12, 28 March 2014 (UTC)

Or if you're already familiar with Python (or MATLAB), check out Matplotlib. SemanticMantis (talk) 20:15, 28 March 2014 (UTC)

DAISY Digital Talking Book

Hello. I'm a student and I have dyslexia, so I'm using finnish audiobook library Celia. They have audiobooks downloadable from Internet using Daisy format. The problem is that they are recommending only expensive Daisy CD-players and programs for Windows. I have a Mac computer and not money for Daisy CD-player. I found free program named Olearia for Mac, but I think this program is quite poor, because it could not save bookmarks or search beginning of a chapter. The audio of the books are divided in 45 minutes mp3 files, so the program thinks that chapters begin in the beginning of the file. Could someone recommend some better audiobook listening program or maybe a mp3-player, which supports Daisy format?

Yours, 178.55.172.60 (talk) 14:12, 28 March 2014 (UTC)

Pagination appearing only on Homepage

Hi, I am facing a new problem in my blog. The problem is pagination is appearing only on Homepage..! While going through the pages it's not appearing..! Here is the HTML code of pagination I'm currently using:

/* Page Navigation styles */
.showpageNum a, .showpage a {
  box-shadow: 3px 3px 2px #888888;
  background: #ffffff;
  padding:0 8px; 
  margin:0 4px; 
  text-decoration: none;
  color:#000000; 
  border:1px solid #000000;
  border-radius:3px;
  -webkit-border-radius:3px;
  -moz-border-radius:3px;
}
 
.showpageOf {
  margin:0 8px 0 0;
}
.showpageNum a:hover, .showpage a:hover {
  box-shadow: 3px 3px 2px #888888;
  color:#ffffff;
  background: #000000;
  border:1px outset #000000;
  border-radius:3px;
  -webkit-border-radius:3px;
  -moz-border-radius:3px;
  }
 
.showpagePoint, .showpage a {
  box-shadow: 3px 3px 2px #888888;
  color: #000000;
  background: #000000;
  padding: 0 8px;
  margin: 0 4px; 
  text-decoration: none;
  color:#ffffff;
  border:1px solid #000000;
  border-radius:3px;
  -webkit-border-radius:3px;
  -moz-border-radius:3px;
}

/*...........................................................*/

<!--Page Navigation Starts-->
<script type='text/javascript'>
var home_page="/";
var urlactivepage=location.href;
var postperpage=6;
var numshowpage=6;
var upPageWord =&#39;Previous&#39;;
var downPageWord =&#39;Next&#39;;
</script><script src='http://mybloggertricksorg.googlecode.com/files/colorizetemplates-pagenav.js' type='text/javascript'/>
<!--Page Navigation Ends -->

Can anyone please tell, what change should I need to make in the above code for appearing pagination in all pages, including homepage?--Joseph 14:50, 28 March 2014 (UTC)

consolidating mutliple pdfs into one document by name

Hey all. (Mac user). I have Adobe Acrobat Professional. I was wondering if there is any way to compile a pdf in one shot of multiple items in a folder that are already, by name, in the order I would want them to be consolidated. I already know how to do it the slow way (document, insert pages and attach each one by one) but it's not very efficient. Here's an example of the contents of a folder:

Page 1.pdf
Page 2.pdf
Page 3.pdf
Page 4.pdf
Page 5.pdf
Page 6.pdf
Page 7.pdf
Page 8.pdf
Page 9.pdf
Page 10.pdf
Page 11.pdf
Page 12.pdf

And I want to create a single pdf of these documents in page order. Anyone know of a way? Thanks.--71.167.166.18 (talk) 14:50, 28 March 2014 (UTC)

I've done this with Ghostscript,an free open-source tool. this article describes a number of techniques, starting with the Ghostscript method. -- Q Chris (talk) 16:05, 28 March 2014 (UTC)

Hi, you can combine PDF files, if you've Adobe Photoshop installed in your system. Here is how to combine PDF files in Photoshop. Hope this will help.--Joseph 16:45, 28 March 2014 (UTC)

You can do it with pdftk by running this bash script:

IFS='                                                                                                               
'
pdftk $(ls Page* | sort	-g -k2) cat output out.pdf

-- Finlay McWalterჷTalk 17:48, 28 March 2014 (UTC)

Yes, Acrobat Pro can do this: on the splash screen that comes up when you open Acrobat, the last item under Select a Task should be "Combine Files into PDF". --Canley (talk) 09:17, 29 March 2014 (UTC)

Does Windows use X deep down in its display code?

20.137.2.50 (talk) 17:18, 28 March 2014 (UTC)

No, I don't think so. See X_Window_System and Windows_operating_system. If MSWin contained any code from X project, they would have to include a copy of the source, as well as a copy of the MIT_License. I haven't used MSWin in years, but I'm pretty sure they've never done any such thing, that's not really how MS does business. I did a quick check for references, but it's hard to find people saying e.g. "Win95 does not use any code from X window system", because it's kind of obvious. A related example: even though OS_X is built on Unix, Apple still developed Quartz_(graphics_layer) for native windowing, though there is a version of X11 that Apple distributed with later versions of OSX, specifically to make it easier for certain Unix programs to be ported to OSX. SemanticMantis (talk) 20:20, 28 March 2014 (UTC)

No, not at all. An outline of Windows display architecture is in this diagram (see the Direct3D System Integration section). Our articles in this space include Graphics Device Interface, Direct X, and Direct 3D. -- Finlay McWalterჷTalk 20:12, 28 March 2014 (UTC)

I assume the implementation of an X server (call it A) or whatever Microsoft's display controller module is (call it B) is at the layer above the hardware level and that a command to make the pixel at position (x,y) have such-and-such rgb values is accomplished by A or B by writing 1s and 0s to the graphic card's memory accordingly. Where can I read about that specification, the graphics card standard that lets A and B implementations know what bytes to put at what memory locations in order to make a certain pixel a certain color? 75.75.42.89 (talk) 20:51, 28 March 2014 (UTC)

Some (e.g. WiredX) were simply GDI programs which drew Xprotocol calls into a GDI window. Fancier ones, which aim to support X extensions for things like transparency, and OpenGL, will have to be built on Direct X. A decent modern example is Xming, which is open source, so you can examine the docs that come with its source. -- Finlay McWalterჷTalk 21:01, 28 March 2014 (UTC)

March 29

Anyone on here still using Windows 2000 Pro?

As we all know, support for Windows XP is ending on April 8th, and I was wondering what life has been like for users of Windows 2000 since the end of support. I just bought a Dell Mini off of eBay that shipped with a clean install Windows XP, to use in real estate business, and I'm trying to decide if I should upgrade it to Windows 7 Pro or roll the dice with XP (or even consider switching it to Linux). I really like Windows XP, but I also don't want to open myself up to trouble. PCHS-NJROTC ^(Messages) 03:51, 29 March 2014 (UTC)

I'd would worry if you are navigating the web with Windows XP, which you probably will, since XP could become a huge security risk without upgrades. OsmanRF34 (talk) 04:14, 29 March 2014 (UTC)

Yes, I would be accessing the MLS from it, which is online. Pardon my French, but this sucks; I've nothing against Windows 7, but I have been in absolute love with Windows XP since I first started using it in 2005 (yes, I was using Windows 98 until then), and I hate to remove it in favor of something else. Time's not stopping anytime soon though, and when it comes to business, security trumps personal preference. So what are these big enterprises that are still on XP going to do? I know there's still a few out there which haven't upgraded. PCHS-NJROTC ^(Messages) 04:49, 29 March 2014 (UTC)

I don't think security threats were as numerous in the W2K era. "Big enterprises" will probably bite the bullet and migrate from XP. Smaller users (including a huge fraction of China) will keep using XP and become even more malware infested than they already are. People keep telling me that Windows 7 is ok and that it's mostly Windows 8 that draws Windows users' ire. So if you want to keep using Windows, I'd go ahead and switch to W7. If you just want basic web browsing and office apps, or if you're a more advanced user who knows what you're getting into, Linux is fine. If you want the corporate shiny experience, most of the hipsters around here use Macintoshes. 70.36.142.114 (talk) 05:52, 29 March 2014 (UTC)

Free support is ending, but paid support will still be available to corporate customers that are sticking with XP for whatever reason. -- BenRG (talk) 05:57, 29 March 2014 (UTC)

I think the key will be avoiding using Internet Explorer with Windows XP. Microsoft will stop patching security holes in Internet Explorer 8 on Windows XP, but you can just use a different browser, like Firefox or Chrome, which will continue to be patched for a while. All the anti-virus programs I know of continue to be supported on Windows XP, as well. So, to be safe, I would make sure you have an anti-virus program. Continue to update any browser plugins like Flash and disable the Java browser plugin. Eventually, I'm sure Firefox and Chrome will drop support for Windows XP, so you won't be able to use that operating system forever. For example, Firefox stopped supporting Windows 2000 with version 12 in 2012. Further, the newest versions of many popular applications I know of (e.g., Photoshop CC and Microsoft Office 2013) aren't supported on Windows XP, anymore. So, that may make it a bit of a pain to continue using it. As for users of Windows 2000, the only business I knew personally to be using it in 2010 actually upgraded to Windows XP Professional before support was cut off. It was different for that OS, though. Upgrading for them just a software upgrade and you just had to install the OS, the drivers, and the applications to get going. Most hardware that ran Windows 2000 ran Windows XP. But Windows 7 is much more demanding on the hardware than Windows XP, so it's going to be harder for many people to upgrade. I know many businesses, government agencies, and individuals who are using Windows XP today, here in North America.—Best Dog Ever (talk) 07:35, 29 March 2014 (UTC)

Well, I just went and did something radical; I ordered a copy of Windows 8.1 off of Amazon. I do believe the system in question will run Windows 8, and it will be nice to have a copy even if it won't. Hello modern OS, bye bye 2001 OS. PCHS-NJROTC ^(Messages) 14:53, 29 March 2014 (UTC)

If all you need to do is browse website, then why not use Linux! Linux is surely your best bet in this situation! Duomillia (talk) 20:17, 29 March 2014 (UTC)

I keep meaning to try Linux. I actually downloaded Ubuntu once, never installed it though. I'll probably be doing my than web browsing from the computer in question. 71.3.50.250 (talk) 14:26, 31 March 2014 (UTC)

March 30

How to know if a hack is taking place?

How does a system administrator know whether a hack has occurred or is occurring? --78.148.110.69 (talk) 10:04, 30 March 2014 (UTC)

Sometimes with a Intrusion detection system. -- Finlay McWalterჷTalk 10:15, 30 March 2014 (UTC)

If the hacker is hacking the system while she's hacking the system, the sysadmin may notice a dancing koala. Or whatever's cool that day. Or just a crash. InedibleHulk (talk) 17:29, March 30, 2014 (UTC)

How do you know someone broke into your house? Sometimes the front door is smashed in and the place is ransacked, other times you might realize that an envelope full of money is missing from your top drawer, and have no idea how or even when it went missing. Vespine (talk) 23:04, 30 March 2014 (UTC)

Lost horizontal scroll bar in Gmail

I use Gmail on Google Chrome on a Windows 7 PC. When I open up a message, it has a vertical and horizontal scroll bar initially. I then zoom (CTRL +) in to make the text larger, and the vertical scroll bar remains, but the horizontal scroll bar disappears, leaving me no way to see the right side of my messages. Is this a known bug ? Is there a fix ? StuRat (talk) 15:03, 30 March 2014 (UTC)

Backdoor (computing) Part II

I'm asking for our more technically inclined editors to add Backdoor (computing) to their watchlists. Apparently, we had editors who don't understand what a backdoor is and are adding off-topic content and conspiracy theories to the article as if they are fact. I've started a discussion on the article talk page.[2] A Quest For Knowledge (talk) 11:08, 31 March 2014 (UTC)