Wikipedia:Reference desk/Archives/Computing/2010 July 13

Welcome to the Wikipedia Computing Reference Desk Archives
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.

July 13

The earth rotates!

Imagine a map projection showing the whole surface of the earth on a flat screen, such as this image. That's a still picture. Is there software that can do the following? I supply in some form information specifying which map projection I want to use, and as output I see the rotating earth using that projection, say doing one full rotation every minute? I would want it to be scrupulously accurate and to look nice. And in a form that could be incorporated into a video that could then be uploaded to youtube. Michael Hardy (talk) 02:53, 13 July 2010 (UTC)

MATLAB Mapping Toolbox can perform arbitrarily complex standard or user-specified map projections, and can be configured to use gory details and precise geodetic information from various international standards (e.g. geoid references like NOAA NGS). You could easily write a simple MATLAB program to load and set up the earth data, configure your favorite globe projection, and using the standard plotting tools, render an animation in 2D or 3D. Unfortunately MATLAB and its Mapping Toolbox are expensive. Nimur (talk) 17:37, 13 July 2010 (UTC)

GNU Octave has a Mapping Toolbox as well; it is less well supported, but probably functional. These tools are free software. Nimur (talk) 17:44, 13 July 2010 (UTC)

Thank you, Nimur. I'll see if the department whose computers I'm using has those. Michael Hardy (talk) 18:54, 13 July 2010 (UTC)

What to do with .cbr files?

How do you see .cbr files, I mean with what application you open them ?  Jon Ascton  (talk) 06:55, 13 July 2010 (UTC)

google ".cbr extension". it seems to be a 'Comic Book RAR Archive', which can either be decompressed using a standard archiving utility, or opened in an assortment of apps designed for reading comic books. --Ludwigs2 07:00, 13 July 2010 (UTC)

It seems to be Comic Book Archive file which according to that page should be able to be opened with anything that can decompress .rar files. Dismas|^(talk) 07:02, 13 July 2010 (UTC)

CDisplay is the program you want. CBRs are just renamed RAR files, so literally all you have to do is change the extension to .RAR and open it however you normally would. Personally, I like using the CBR setup because it keeps things neat (one file, not fifty), takes up less space (due to compression), and can easily be switched back to individual files should the need arise. CDisplay is a good program which I've used for years, but the default settings may not match what you want - all the settings can be adjusted, however. Matt Deres (talk) 16:23, 14 July 2010 (UTC)

Creating a Firefox Persona

I'm trying to make my own persona, but when I select an image from my personal folders, the image only appears at the very right-hand corner of the header and at the left-hand of the footer. It never fills up the entire browser. Even with photo editing software (Paint.NET in case you're wondering), it never turns out right. Yet the sample pictures that are in the My Pictures folder have no problem looking as it should for a theme in the browser. How do I make my custom persona look right with my own pictures? 24.189.88.30 (talk) 07:35, 13 July 2010 (UTC)

Your persona will only ever occupy the header and footer, never the entire browser. If it is only appearing in the corners, I would guess that the images are not large enough – they should be 3000px wide and 200px or 100px tall for header and footer respectively. See How to Create Personas for more info. AJCham 08:58, 13 July 2010 (UTC)

Excentro or another guilloche generator for windows

Does anyone know of a Windows programme (free or open-source) with the same functionality as Excentro? ╟─TreasuryTag►CANUKUS─╢ 18:19, 13 July 2010 (UTC)

Searching for "harmonograph simulator" in Google produces some results, see also Spirograph. 92.24.177.162 (talk) 21:37, 13 July 2010 (UTC)

Strange image results in Google

In trying to help answer a question, I noticed a lot of my search results led to similar web pages. For example, on this result page, of the 21 results I can see: 9 are links to sites all named "tattoo<random 5-digit number>.info", 3 are links to sites all named "tattoos<random 5-digit number>.info", and 5 are links to sites all named "wallpaper<random 5-digit number>.info" - leaving just 4 that are links to other sites. If I click on any of the "tattoo" links, I am taken to a page advertising stuff related to body art and if I click on any of the "wallpaper" links, I am taken to a page advertising stuff related to desktop wallpapers; in any case the image I clicked on is not on that site. In fact, the site I end up on is the result of a redirect from the site with the image. It looks like somebody has registered hundreds (or thousands) of similar addresses and arranged for a huge effort in redirecting pages to their random sites. Is this the result of fancy Search Engine Optimisation? Are Google's results being corrupted in some way? Or do I have some malware that is intercepting my Google results and rewriting the page on the fly to push their sites? Currently running MalwareBytes, to see if it's my PC that is causing this, but I would be curious if others are seeing the sme thing I do. Astronaut (talk) 12:16, 13 July 2010 (UTC)

It looks like someone is gaming the system a bit. It's not just on your end of things; it happens on my Mac as well. --Mr.98 (talk) 12:33, 13 July 2010 (UTC)

Thanks. MalwareBytes found nothing after a thorough scan, so that's a relief. It is still odd though. Astronaut (talk) 18:38, 13 July 2010 (UTC)

This is an example of black hat search engine optimization called cloaking. The site detects when the search engine's indexing robot is requesting the page and shows it relevant content that will rank well in searches. But when other people visit, the page instead shows ads the site owner can profit from.

In this case, the images themselves come from other websites. If you right-click a image in the results page and copy the link address, you can find the direct image link between imgurl= and the following &. This is tedious to do manually, so if you decide to do this often, you can find web browser add-ons that will help you go directly to the image address embedded in Google image search result links. --Bavi H (talk) 02:45, 14 July 2010 (UTC)

Thanks. I've reported this problem to Google. I then found this discussion on Google's help forum - this kind of thing has been a problem with Google's image search for some weeks now. Astronaut (talk) 03:57, 14 July 2010 (UTC)

"CLICK CLICK CLICK WHIRRRRRR. CLICK CLICK CLICK WHIRRRRRR" - my laptop's hard drive

By now I'm pretty well aware of how badly I screwed the pooch on this one, and will be buying a new hard drive pretty soon. But I did have some stuff I liked on the other one, that I hadn't backed up yet. For purpose of these questions, it is an 80gb drive on an HP dv1000 (I think it came with the laptop), dual-partitioned to WinXP and Ubuntu although neither is able to boot because sectors 00-07 (i.e. all of them) are junk according to the BIOS integrity check.

1. I've heard of putting clicking drives in the freezer and having them work for a few minutes - assuming this works, how long would I have for the
2. Would I be able to, post-freezing, mount it as a secondary drive (with the newly-bought one as primary)?
3. If so, could I do it while the laptop was already booted, therefore giving myself more time to copy and less time to dick around with booting?
4. Will this whole rigamarole work if I install Linux on the new HD?

ZigSaw 13:14, 13 July 2010 (UTC)

Wow, it's you! I don't know the answer to your question, but welcome back to Wikipedia! I was very sad when you got banned last year 82.43.90.93 (talk) 13:45, 13 July 2010 (UTC)

Ziggy was actually banned from 2007 to 2009, in other words he was unbanned last year not banned last year. This particularly account was blocked for a short time last year after it was uncovered he was a banned user but was unblocked after about 1.5 months when he/she made a successful unban request. Nil Einne (talk) 00:39, 14 July 2010 (UTC)

No, you shouldn't freeze your electronics, including hard disks. They are not rated for freezing temperatures, and moisture will condense on your electronics, too, which could cause damage when you turn it on. Comet Tuttle (talk) 16:19, 13 July 2010 (UTC)

I've heard a lot of anecdotal success stories about freezing (such as this one). It's worth trying as a last resort. You should plug the drive into an already-running system to recover data, not boot from it as that guy did. -- BenRG (talk) 19:05, 13 July 2010 (UTC)

You can definitely try to mount your old drive as a secondary drive with the newly-bought one as primary. It might not work at all, or it might give lots of errors, so be prepared for the worst. The easiest way to do it with a laptop is a IDE/SATA USB adapter, which you can pick up online for ~$20. They're quite common. And yes, you'd probably want to plug it in after the laptop was booted, so you could get the most out of your limited time. And yes, installing Linux on the new HD shouldn't make a difference. Linux works quite well for hard disk recovery, especially since the ntfs-3g drivers became standard. Indeterminate (talk) 17:32, 13 July 2010 (UTC)

Name for padding function

I want to do a formatting in OpenOffice, but I don't know what it is called. I want to have a list that has a left-justified column and a right-justified column. The padding between the two columns is variable (depending on content per line) and I want the padding to be filled with periods (or dots). What is this type of justification and padding called so I can search for the method of setting up the paragraph style? -- kainaw™ 14:03, 13 July 2010 (UTC)

If you mean a line of periods like in a table of contents, they're apparently called "dot leaders". This page discusses them in OO. --Sean 14:54, 13 July 2010 (UTC)

Thanks. That works. -- kainaw™ 16:14, 13 July 2010 (UTC)

Combining images into a PDF

I have a folder containing images such as image01.jpg, image02.jpg, image03.jpg..... (or perhaps image01.png...). Is there any free software that could join them together in sequence as a PDF? Thanks. 92.24.184.61 (talk) 14:06, 13 July 2010 (UTC)

With ImageMagick:

convert -adjoin -page A4 image*.jpg output.pdf

--Sean 14:49, 13 July 2010 (UTC)

PDFTK (website) is also free; I don't think it accepts JPG as input files, but it can do many other useful operations on PDF. Nimur (talk) 17:39, 13 July 2010 (UTC)

Thanks. How would I do the ImageMagick command above please? I am used to GUIs. I have XP. Thanks 92.24.177.162 (talk) 21:20, 13 July 2010 (UTC)

Download the Windows version of ImageMagick and install it. Open a command prompt and run it using the command specified above. Nimur (talk) 21:39, 13 July 2010 (UTC)

Am I correct in thinking that I will need to navigate in the command prompt window to the folder where the ImageMagick software is? How can I do that? Thanks 92.29.127.224 (talk) 13:49, 14 July 2010 (UTC)

No, as the software should put the command in your PATH so you can use it from anywhere. You will have to navigate to where your images are (let's say they're in E:\my\pics), something like this:

E:
cd \my\pics
convert -adjoin -page A4 image01.jpg image02.jpg image03.jpg image04.png output.pdf

--Sean 16:16, 14 July 2010 (UTC)

IrfanView (free for personal use) is supposed to be able to do the job if you download and install the Plug-Ins in addition to the main program; the menu option is Options → Multipage Images → Create Multipage PDF. PleaseStand ^(talk) 04:07, 14 July 2010 (UTC)

Got a spam Facebook friend request from someone with similar name to one just mentioned in an email -- hacked account?

Hi all,

My mother just sent me some financial information, and cc'd her bank advisor -- let's call her "Roxanne Courn." This was the first time "Roxanne Courn's" name or email was ever sent to me email. Two hours later, I got a spammy-looking Facebook friend request from a (let's say) "Roxane Korn." It looked like spam because I've never heard of this person, and s/he has just five friends none of whom I know. This request, as you may have noticed, was from a person with an extremely similar, though slightly different, name from the one just mentioned.

Now, I get several spammy facebook friend requests a week, so this could easily just be coincidence. But do you think that there's any chance that either my, my mother's or (the original) Roxanne's emails are compromised? That some automated spam-bot said "let's send him a friend request from someone with a similar name to that just mentioned, just in case he clicks on it thinking it's the same person?" Is such a scheme a known strategy? Or am I being paranoid?

Thanks! — Sam 63.138.152.135 (talk) 21:01, 13 July 2010 (UTC)

It seems odd that they would misspell the name if they have the actual, correct version. I suppose one could imagine some sort of case where it was mechanically transliterated into Chinese or Russian and then back into English again, I guess, but that would be awfully inefficient... --Mr.98 (talk) 21:08, 13 July 2010 (UTC)

Could they have a farm of existing facebook accounts, and whenever they match to something similar send a request from one of them? Reaching a bit here, probably. — Sam 166.186.168.45 (talk) 21:24, 13 July 2010 (UTC)

Hundreds of identical files on Windows HD - thanks Bill.

I have XP and I've run a program that finds duplicates on the HD. a) It has found about a hundred identical copies of update.exe. They are 0.75MB each. Is there any sensible way of diminishing their number? b) Is Linux better designed than Windows - does Linux just keep one or two copies of system files in some central repository rather than having a hundred identical copies all over the place, as Windows does? c) I also have hundreds of different files that are exactly zero bytes long - would it probably be safe to delete them? Thanks 92.24.177.162 (talk) 21:28, 13 July 2010 (UTC)

What directories are your copies of update.exe in? As for the 0-byte files, I would not delete them; I know some people hate computer directories that they see as "junk drawers", but some applications may write a 0-byte file just to keep a note around that some situation or other has occurred, or not occurred. Since they presumably are not affecting your computer in any way, "if it ain't broke, don't fix it." Comet Tuttle (talk) 23:06, 13 July 2010 (UTC)

If the copies of update.exe are underneath a folder named Windows\$hf_mig$, then the standard advice is to not delete this folder, since it's needed for correct installation of later updates. You can safely delete folders with names starting with $NtUninstall, along with all of their contents; this can free up a lot of space, though you will lose the ability to uninstall the updates. Deleting zero-length files will not free a noticeable amount of space and can cause problems; don't do it. -- BenRG (talk) 03:10, 14 July 2010 (UTC)

If you want to clean your computer use CCleaner. I use it across 800 computers. --mboverload@ 05:31, 14 July 2010 (UTC)

As far as I recall the update.exe filers are in many different places. I already regularly use Ccleaner, CleanUp! and Window's own disk clean-up. Thanks 92.29.127.224 (talk) 13:41, 14 July 2010 (UTC)

Do you have the option to clean hotfix installers enabled? Doing things to clean the Windows system itself other than using proven safe programs like CCleaner I can't recommend unless you're familiar with the workings of the Windows operating system. --mboverload@ 01:23, 15 July 2010 (UTC)

Yes I do. 92.15.9.213 (talk) 08:02, 15 July 2010 (UTC)

Searching for and fixing corrupt zip files

I have a large number of corrupt zip files throughout my HD. Although I know of freeware that will attempt to fix a corrupt zip file if you tell it what the filename and path is, is there anything that will search for them itself without having to be explicitly told about every individual file? 92.24.182.102 (talk) 22:53, 13 July 2010 (UTC)

I'm curious how you ended up with a large number of corrupt zip files throughout your hard drive. Anyway, assuming you're running Windows, you could open a command prompt and run this:

for /r c:\ %i in (*.zip) do (zip -T "%i" || move "%i" "%i.broken" && zip -FF "%i.broken" --out "%i")

That will process all of drive C. Replace the "c:\" near the beginning with another folder name to process the subfolders of that folder. You will need zip.exe and unzip.exe (Info-ZIP). The original broken files are retained with ".broken" appended to the end. I take no responsibility if this makes matters worse instead of better. There's no magical way to repair zip archives perfectly. -- BenRG (talk) 08:11, 14 July 2010 (UTC)

Thank you greatly! Curious, what language is the line above written in please? The corrupt zip files were probably due to zipping up a lot of stuff from an old computer into a big zip file, copying it to a DVD, reading the DVD on my newer computer and unzipping the big zip drive.

I recall a file copier from Korea that was unusual in verifying what it had written, which would have been useful for that, but do not recall any more details. 92.29.127.224 (talk) 13:36, 14 July 2010 (UTC)

(Those are commands for Command Prompt, and although this set of commands are not a "complete" programming language, they are commonly used for batch scripting). Nimur (talk) 18:00, 14 July 2010 (UTC)

At what point in that process do you think the zip files got corrupted? The first thing I'd try is reextracting them from the DVD. Data loss during file copying would indicate a serious problem with your hardware. I'd advise against continuing to use a computer that occasionally corrupts your files. -- BenRG (talk) 20:04, 14 July 2010 (UTC)