Wikipedia:Reference desk/Archives/Computing/2007 August 22

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.

August 22

converting lat/long to pixel coordinates

How would one go about converting a series of latitude and longitude coodinates from a given map projection (say, Robinson) to pixel values (that is, assume that said map is a raster image of given length and width, and say we know exactly which pixel the prime meridian is on)? It seems like something that should be out there already, but I am not having an easy time finding the relevant code. I am sure it is some sort of nasty matrix transformation? --24.147.86.187 00:36, 22 August 2007 (UTC)

Interesting question. For a small-scale map a linear scaling would do the job, but I assume you mean a map large enough so that noticeable curvature in the lines of longitude occur. Even worse would be projections that tear the map into strips. I know of a site that seems able to do what you want (or, at the very least, they can calculate the distance between two map points), perhaps you can ask them how they do it: [1]. StuRat 04:23, 22 August 2007 (UTC)

Sorry but I'm not too clued up on how to interpret maps (what with curves and things), but here's my input: This sort of thing is technically doable both manually and programatically, all depending on how technical you want to go. For example if your map's horizontal axis goes from 0° to 180°, then if your map image is 600 pixels wide, then you know that 0° is pixel 1, and 180° is pixel 600, and therefore 90° is pixel 300 -- that sort of thing. Or by distance you would calculate your unit on your map image, i.e. 1 pixel = x miles/killometers. If you measure 10 miles on your map then on the image that's 25 pixels. Problems of course come in with things like distortion, curves, etc. 1) Do you require this to be done on only one map, or several? 2) How important is accuracy? Rfwoolf 16:25, 22 August 2007 (UTC)

Anyone heard of this? Windows XP cannot ALT-TAB or switch tasks properly

I upgraded to Windows XP about six months ago and there's a feature called ALT-TAB.

For reference, I have "group similar taskbar buttons" unchecked because I dislike that function.

Before Windows XP, if I have a window open then I click in the start menu to another menu, then I hit ALT-TAB, it'll go to the previous window. But in Windows XP, ALT-TAB goes to a random window and not my last window. I basically have to click back and forth between then in the start menu 10 times before ALT-TAB between them works like in previous windows versions.

In additon, I may also have two notepad windows lined up as I'm using them both together--sy NotepadWindowA in the left corner and NotepadWindowB in the right corner--and well when I even click back and forth between them in the start menu (not the window, but the start menu), Windows XP refuses to keep both Notepad windows in the foreground and instead randomizes all window-on-top orders when I click between them in the start menu. I basically have to click back and forth between then in the start menu at least 10 times before clicking back and forth between them in the start menu works like in previous windows versions.

I've been trying to find information on google and it gives no information. Is there even a name for these Windows XP bugs/features so I can look for it? Juanita Hodges 02:26, 22 August 2007 (UTC)

Vista? Linux? Sorry for the unhelpful answers but XP does have its quirks --froth^t 04:44, 22 August 2007 (UTC)

I also use XP with "group similar" unchecked and I don't have this problem, for what it's worth. -- BenRG 10:37, 22 August 2007 (UTC)

If you hold down ALT while pressing tab multiple times I believe it lets you choose between the available windows. Not quite the answer you want but it makes it a little bit easier, perhps? I don't have the same problem you describe; I'm pretty sure mine goes back to the window of the application I most recently used. --24.147.86.187 14:53, 22 August 2007 (UTC)

First of all, unchecking "Group similar taskbar buttons" is, as far as I'm concerned, the only way to go. I change all computers I go near to that. Secondly, you speak of the "start Menu" when in fact I think you're talking about the TaskBar. The Startmenu opens up a whole lot of program shortcuts etc - whereas the taskbar at the bottom next to the start menu where open programs sit. About your problem, one thing I can think of is that perhaps you have a 3rd party tool installed that has messed with the way windows is handling its... windows. Good luck Rfwoolf 16:19, 22 August 2007 (UTC)

If you do Alt+Tab but don't release the Alt key, does it give you the list of open windows? 68.39.174.238 18:49, 22 August 2007 (UTC)

Yeah, I meant task bar. Anyone know the proper name for these Windows XP problems so I can google for it? Juanita Hodges 21:43, 22 August 2007 (UTC)

Don't know if this helps, from Alt-Tab: Applications have some say in where they are located in the Alt-Tab order. The list of windows is altered by the creation and destruction of windows, programmatic hiding, showing, raising, and lowering of windows, and alterations to the window z-order.

So it seems that some programs override this, one example of something like that was Adobe 7.x

Also, familiarise yourself with these commands: Alt + Tab, Alt + Shift + Tab, and Alt + Shift + Esc

The article Alt-Tab is worth a read-through.

Rfwoolf 14:09, 23 August 2007 (UTC)

GoDaddy page appears for all invalid domains

I'm on Sympatico (provided by Aliant in eastern Canada), and no matter what domain I look up (even if it's a single word, like an invalid TLD) takes me to a page titled "This Web page is parked free, courtesy of GoDaddy.com!", at 68.178.232.99. I only have access to a Windows machine on this connection at the moment so the ping command is the best I have, but WTF? Is this the ISP doing something like what Verisign did awhile ago with their SiteFinder service? --Silvaran 03:45, 22 August 2007 (UTC)

GoDaddy cybersquats a lot. Or else it could be your ISP or spyware on your computer. Juanita Hodges 04:21, 22 August 2007 (UTC)

Turns out I had chosen a domain that was "parked" by GoDaddy as the default domain on my little d-link router/switch. So this gets sent to clients through DHCP, and everything (including ping) appends this domain and does a second look-up. Since GoDaddy has a wildcard set up on that particular domain, I always get a parked page. SO it was my own stupidity... ahh well... --Silvaran 17:45, 22 August 2007 (UTC)

Note that GoDaddy (the company) is not the one that does the cybersquatting; they are a domain registrar and cybersquatters use registrars to squat. --140.247.240.228 19:24, 22 August 2007 (UTC)

Mm, I don't think so. --froth^t 01:52, 23 August 2007 (UTC)

Need HDTV 1080i recorder

Not a camcorder, mind you, just a way to record 1080i broadcasts, primarily for time shifting (recording them while at work then playing them later). A standalone unit that attaches to the TV will work, either recording to a built-in hard drive or burning to DVD. Alternatively, it can hook up to the computer and use it's hard drive and/or DVD burner. So far, the only thing I've found close seems to be the Sony RDV-D60C, which doesn't appear to be for sale yet, at least in the US. I've found lots of camcorders that claim to record 1080i, but they want to record it on tape, which does me no good. Also, I don't want to pay for a camcorder I don't need. Any recommendations ? StuRat 04:04, 22 August 2007 (UTC)

I only heard of the hard drive things like tivo. Juanita Hodges 04:21, 22 August 2007 (UTC)

Does TiVo do 1080i ? StuRat 04:27, 22 August 2007 (UTC)

Lord knows. I have a DVD-RAM recorder now. It depends on the show whether 1080i is important. I prefer to tape everything as a noisy neighbor or dog and ruin a show if not taped. I like the DVD-RAM disks as when the recorder breaks down, the taped shows are still good and I only need one thing that can play may DVDs I rent, too. They don't even make a DVD-Ram recorder that has High def inputs (mine has outputs but not inputs). They should make some recorder that has High def inputs and outputs. The only thing I can think of is one of those recorder types that are basically just a hard drive and that's it-- no CD shaped disks. If you find something good, please leave me a talk message especially if you find a disk version. Juanita Hodges 04:34, 22 August 2007 (UTC)

Do a google search for "atsc capture card" and you'll find any number of gadgets which plug into your computer and allow you to same the video stream to your computer hard drive. --136.186.1.191 07:05, 22 August 2007 (UTC)

Of course, if you're in in a country that uses DVB, you'll need a DVB capture card, not an ATSC one. --136.186.1.191 07:06, 22 August 2007 (UTC)

Tivo Series 3 support 720p and 1080i recording. --24.249.108.133 15:06, 22 August 2007 (UTC)

How about the cheaper TiVo HD ? I can't find any documentation on if it can record 1080i or only 720p. StuRat 15:28, 23 August 2007 (UTC)

Yes. See here, near the end of the page, just before "Conclusion." --LarryMac | Talk 18:48, 23 August 2007 (UTC)

So it does record 1080i (and 1080p if you can find anyone broadcasting it), right ? Also, what happens if your subscription runs out, does the unit cease to work in any way or still work on a basic level ? StuRat 21:08, 23 August 2007 (UTC)

I believe that TiVo has made their newer units reliant on a continuing subscription. --LarryMac | Talk 14:35, 24 August 2007 (UTC)

I use a pcHDTV card on my Linux system to record broadcast HD content using MythTV for time-shifting. I don't burn the content to DVD, though, since I don't really care about archiving the content. -- JSBillings 11:47, 23 August 2007 (UTC)

That's one way to go, but doesn't that require a fast computer, say 2.8 GHz or above ? StuRat 15:28, 23 August 2007 (UTC)

File Format of Azureus download

in what file formst does Azureus download? If a file (say, bloomer.avi or diehard4.avi) is being downloaded through Azureus, then what does a Network Administrator see on his screen? Is the full name of the file being downloaded visible to him? If you change the visible name of the file being downloaded then is the Network Administrator still able to see the original file name?

It comes down to this: If you're downloading what you're not supposed to be downloading, then expect to get caught. Capuchin 11:29, 22 August 2007 (UTC)

Like any P2P program, it downloads things in the format that people upload them in. If someone seeds a .AVI and you download it, don't expect it to come out as a .RM or .WMV. 68.39.174.238 18:51, 22 August 2007 (UTC)

What he/she is asking, and I don't know the answer, is what would P2P traffic look like to a network administrator? Obviously it will look like a lot of activity on non-HTTP ports (torrent programs use lots of weirdo ports and I imagine the activity is very distinctive looking), but would the network admin be able to tell what files were being downloaded over the ports? I don't know enough about protocols to answer this, personally. --24.147.86.187 00:50, 23 August 2007 (UTC)

Well the answer is nope, unless they have a deep packet inspection appliance, and nope in all cases if you enable encryption and "disable incoming legacy connections" --froth^t 01:53, 23 August 2007 (UTC)

Well my question is exactly what 'Froth' and 24.147.86.187 are talking about. Does P2P traffic give any clue regarding the type and name of the file being downloaded? Also 'Froth' has explained regarding utorrent but can anyone explain regarding Azureus?

Come on, if you are on a propriety network of any company which takes their IT half seriously then you are crazy to download anything against that might be against policy, no matter how small you think the chance of getting caught is. "Deep packet scanner" my butt, we bust people with simple scans of proxy logs and profile caches. Those sockets if they aren't blocked will be like a red flag that something is happening on your machine which would be more then enough reason for a half alert admin to investigate further. On the otherhand, if you're talking about the computer at the dog wash or hair dresser that you work at, then you're probably safe... It comes down to a very simple question, yet I'm stunned people are surprised when they are walked off the job site, IT DOES HAPPEN: If you think getting a pirate version of die hard 4 is worth losing your job over then go for your life. Otherwise, rip it off DVD or find a friend who downloads it at home.Vespine 05:16, 23 August 2007 (UTC)

AFAIK, Azureus also has options to enable encryption and disable incoming legacy connections, though these two options are probably named differently. Also, if Network Administrator suspects you of downloading illegal torrents he can just block you from accessing any torrents. And like Vespine said, pirating is not worth loosing your job over. — Shinhan < talk > 14:59, 25 August 2007 (UTC)

Websites Hacked?

I try going in to the website at http://www.goskateboardingday.org and it keeps redirecting me to this: http://ertugrulgazi.byethost31.com/hacked/ . Anybody else experience this? If so please reply as I'm pretty sure my computer is spyware free. 71.112.226.247 06:21, 22 August 2007 (UTC)

Nope, goes straight to the site. --antilived^{T | C | G} 08:30, 22 August 2007 (UTC)

Could be you've got spyware in your browser that's redirecting you to another website. You might try and disable browser plugins and see if it still does it. Since you have spyware, I'm going to save time and assume you're using Internet Explorer, in which case go into Tools, Internet Options, Advanced, Enable thirdparty browser extensions, and uncheck it. Once you've restrated your computer, go back to http://www.goskateboardingday.org if it works this time, they you've got spyware.--69.118.235.97 12:04, 22 August 2007 (UTC)

Never mind everything I just said, you don't have spyware, I just went there in IE and got the same bad redirect that you got to http://ertugrulgazi.byethost31.com/hacked/. My guess is it's a browser exploit that only works in IE.--69.118.235.97 12:13, 22 August 2007 (UTC)

It does the same thing in Safari after a second. Basically someone found a way to insert <meta http-equiv="refresh" content="1;URL=http://ertugrulgazi.byethost31.com/hacked/"> into the "poll" part of the page. Pretty primitive; my guess is that their "poll" script was not secured against an SQL injection or something along those lines. Any time a web page allows user input it introduces opportunities for exploitation if the web designer does not know about properly escaping characters, etc. I have seen (and helped correct) very high-profile, official sites that suffered from this simple flaw. If that's the case they are lucky that the "hacker" just wanted to point them to a different page, rather than, say, deleting their whole database. --24.147.86.187 14:49, 22 August 2007 (UTC)

24.147.86.187 has it exactly right, as I can see in Lynx. Damn script kiddies. --h2g2bob (talk) 21:45, 22 August 2007 (UTC)

Even Firefox redirects to this page... Stupid scripts... --_{Hdt83 Chat} 01:47, 23 August 2007 (UTC)

Sounds like a pretty neat prank to me; I wouldn't even call it hacking to get the point to deciding whether it's leet/skiddie --froth^t 03:38, 23 August 2007 (UTC)

I can see that several days after the question was answered the website is still hacked. To be precise, in your index.asp page, in the featured event table on the left, there is code saying: <meta http-equiv="refresh" content="1;URL=http://ertugrulgazi.byethost31.com/hacked/"> Remove this code to stop the problem for now, and make sure to escape characters such as ' and " when user input is allowed. -- StevenMc, 09.50, 27 August 2007 (BST)

duplicates in outlook express

Are there any freeware programs to remove the duplicates from outlook express? All I can find are fee based programs by mostly MVP's (Microsoft very important person?), while the OE programming error that causes the duplicates is obviously correctable by Microsoft but not being attended to by Microsoft - possibly for no other reason than the financial benefit of those MVPs. Clem

Fonts in PDF

I have a PDF file where there's a character that appears as a square. Is this supposed to be a square or is it a missing character? Is there a way I can find out how to fix the missing character? (I didn't think that PDFs worked on the basis of fonts, but it's a character in a formula, so i doubt it's a square... i might be wrong). Capuchin 14:30, 22 August 2007 (UTC)

If properly made PDFs package their needed fonts with them. If improperly made, they don't, and rely upon the user's system fonts. To find out if there are font issues, open up the PDF in Adobe Reader, then go to File > Document Properties > Fonts. That should, I think, tell you if anything has gone horribly wonky. --24.147.86.187 14:44, 22 August 2007 (UTC)

It just gives a list of fonts used in the document and not a lot else. They all say either Embedded or Embedded subset next to them. Hmmm. Capuchin 14:52, 22 August 2007 (UTC)

Then it might be a problem with the font itself being displayed correctly on your machine. I've had trouble with embedding fonts in the cases where the original font files were only postscript or only truetype or only something else, I can't quite recall, and the final PDF would come out looking quite incorrect. (I think it was in cases where I did not have PostScript equivalents for the fonts but I might be wrong.) --24.147.86.187 14:56, 22 August 2007 (UTC)

Okay I'll try it on my home PC, if anyone else has any ideas, please do chime in :) Capuchin 15:15, 22 August 2007 (UTC)

I don't know all the ins and outs of how this is done, but there's some fonts that are set up in such a way that they will not allow you to embed them in PDFs (I think it's due to copyright, but don't exactly know why they'd do it, as it makes the font rather less useful). Now, if the person that created your original PDF didn't check that the file had created properly, or ignored the error messages on file creation, it's quite likely the missing character was never in the PDF. I've met this problem myself - the only ways around it are to use a different font, or probably to do something illegal. Seeing as you're the user, not the creator, if this is the issue there's nothing you can do, short of guessing what should be there or contacting the creator and asking them. --jjron 08:18, 23 August 2007 (UTC)

It's a paper published by the IOP, I can't quite work out how to contact them though, it's surely something they would want corrected. Capuchin 09:02, 23 August 2007 (UTC)

Edit: Found their customer service desk, they'll throw it to the right place. Hope I don't end up looking like a fool when they say "yeah... it's meant to be a square." Capuchin 09:31, 23 August 2007 (UTC)

If you have no luck there, you could tell us the 'missing' character in context or link to the PDF if it's on their website; someone may or may not be able to suggest what it is, or at least take a shot at whether it really is a missing character. Good luck. --jjron 01:43, 24 August 2007 (UTC)

How accurate are biometric tools at the present time ?

How accurate are biometric tools at the present time ?

How accurate are the biometric tools used in various large scale biometric programs operating at the present ?

Why is there little resistance to having biometric information taken ?

Oh and will answering any of the above cause you to be put on a list ? (just kidding with the last question there). —Preceding unsigned comment added by 202.161.29.246 (talk)

See the top of the page. Do your own homework, please --lucid 00:29, 23 August 2007 (UTC)

WP:AGF is another good one to read, as is WP:BITE DuncanHill 00:33, 23 August 2007 (UTC)

WP:AAGF is another good one to read, as is WP:CIV --lucid 00:45, 23 August 2007 (UTC)

Could some one actually answer this question ? I would like to see an answer. I also do not see how saying how accurate they are would answer a homework question. Lucid did I miss something ? If you know the answer Lucid, please reveal it. Dbmoodb 01:30, 23 August 2007 (UTC)

I don't know, but biometrics is a good place to start. It's just the individual questions that might not be answered (as before, do your own homework). x42bn6 Talk Mess 11:31, 23 August 2007 (UTC)

Hit Highlighting in SQL Server

I've been looking into the text search capabilities of Microsoft SQL Server, and I like how it lets you put full-text searches right in your SQL WHERE clause. I think it would be an excellent search platform for a couple of my applications, but it seems to lack two important capabilities:

First, the ability to take your search results and get a little excerpt from the full-text field that contains your search terms. I think I've explained that poorly, so let me give an example. When I do a Google search for "rats", the results page doesn't just display links, but also little excerpts from the pages:

Rat - Wikipedia, the free encyclopedia

Rats are various medium sized rodents. "True rats" are members of the genus Rattus, the most important of which to humans are the black rat, Rattus rattus, ...

en.wikipedia.org/wiki/Rat - 68k - Cached - Similar pages - Note this

Rat Management Guidelines--UC IPM

UC home and landscape guidelines for control of Rats.

www.ipm.ucdavis.edu/PMG/PESTNOTES/pn74106.html - 50k - Cached - Similar pages - Note this

I want it so that, when I make a full-text query for "rats" part of my SQL Server search, it can generate a list similar to the above.

Second is the ability to provide a view of the document where the hits are highlighted. To give another example from Google, I did a search for "discrimination pdf" and got this:

(PDF) The Evolution of Price Discrimination in Transportation and its ...

File Format: PDF/Adobe Acrobat - View as HTML

decreasing price discrimination. This is described in detail in Odlyzko (2000b) and .....

www.rnejournal.com/articles/odlyzko_RNE_sept_2004.pdf - Similar pages - Note this

When I click on "view as HTML", it gives me an HTML version of the PDF where every instance of the word "discrimination" has been highlighted yellow, and every instance of "pdf" has been highlighted blue.

Are these things that SQL Server can be made to do? Perhaps with the help of third-party add-ons?

--Ryguasu 15:43, 22 August 2007 (UTC)

I'm not familiar with MS SQL Server - but I'll have a guess in case it helps you. The SQL server will only 'serve' the data to you, but you'll need an application to take that data and display it as you wish. You can do a search for all entries in the database that contain the word 'rat', but then once that 'view'/'table' has been fetched for you, you will need to display it, and iterate through the data for the words 'rat', and tell your application to highlight it or put it in bold. To put it another way, your SQL server is your 'back end' where the data lies, but you will need a 'front end' where your users interact with this data - it is in the front end where the highlighting/bolderising comes in. You yourself are probably using Microsoft SQL Server to interact with your data as a front-end as well, but that's not really how the users will be doing it, unless you'll be telling them to open Microsoft SQL Server. Hopefully someone with more knowledge on Microsoft SQL Server can clarify. Rfwoolf 16:11, 22 August 2007 (UTC)

I seriously doubt that the "Microsoft" in front of "SQL Server" entitles you to some super advanced superset of SQL that has these capabilities. Likely (and this is the best solution IMO) you're stuck with SQL and you have to write your own clever script to parse results --froth^t 03:40, 23 August 2007 (UTC)

Let me get you started.

PHP: $highlighted_results = str_ireplace($searchterm, ''.$searchterm.'', $results);

Perl: $highlighted_results = $results =~ s[$searchterm][$searchterm]ig;

You're probably using ASP if you want to use MSSQL rather than MySQL so these won't help much. Sorry! JoshHolloway 18:27, 23 August 2007 (UTC)

At what size does 720p HDTV become unwatchable?

I'm considering buying an HDTV. Seems like most of the marketing buzz is all about 1080p. But 720p sets are generally less expensive. So what what size does 720p become noticeably fuzzier or less sharp than 1080 (if at all)? --24.249.108.133 16:20, 22 August 2007 (UTC)

It depends on distance from screen - an 80 inch projection at this resolution might look OK from the back of a lecture hall, but a 23 inch LCD would be noticeably blocky i you were sat within a couple of feet. Obviously both these extremes are unlikely, but even at more moderate distance from the screen, it has a big impact. Davidprior 23:34, 22 August 2007 (UTC)

Let's say I'm 6' away. Would a 42"-47" 720p make my eyes hurt? --24.249.108.133 03:05, 23 August 2007 (UTC)

No, it won't make your eyes hurt, but you would be able to tell the difference. If you do decide to get a 1080p, Westinghouse has a 42 inch model (TX-42F430S) for US$1080 at Best Buy (that's exactly $1 per line of display, coincidence ?). StuRat 05:51, 23 August 2007 (UTC)

Fading text in Flash CS3

I'm trying to make a little custom way to on-the-fly generate a small bit of text in Flash CS3 that will fade in, stay on screen for a second or two, and fade out.

Now I've done this in a way that I feel ought to work, but it doesn't work. I'm not sure where my error is.

I've created a library movieclip called fadingText that I have exported to Actionscript so that I can create new instances of it on the fly. Basically I call a function within fadingText from the main timeline which causes the fadingText to create a new TextField() inside itself with the text displayed on it. The fadingText then tries to set its alpha to 0, and then starts a timer which increases the alpha by .1 or so over a given duration. When alpha==1 (100%), it starts another timer that doesn't trigger for a few seconds (allowing the text to just be displayed). After that timer calls, it calls another timer which reduces the alpha by .1 or so until it is 0.

To me this seems like it should make sense: set some text within a movieclip, cause the movieclip to fade in and then fade out. Except it doesn't work at all. The text doesn't fade at all, no matter whether I set its alpha or the movieClip's alpha or whatever. The TextField() created on the fly just does not seem to be affected by the alpha setting.

In trying to debug it I tried creating a random square on the fadingText movieclip. This will be affected when I changed the movieclip alpha, and fades in just fine, but instead of fading out it just immediately vanishes. Then it will occasionally re-appear or fade in again. I suspect that somehow its alpha is being set from one of the many fadingText's I have created from the main timeline, though they are supposed to be independent entities.

What am I doing wrong, in terms of the fading or the creation of the movieclip instances? Any suggestions? If there is a better way to create fading text, I'm happy to adopt it, but remember that it must be done on the fly and the fading duration should be variable through Actionscript (in other words, setting up a long shape-tween won't cut it). --140.247.240.228 19:32, 22 August 2007 (UTC)

I know nothing of Flash but couldn't this be achievable without flash, using simple javascript? Although it only work on uniform background, can't you just set the colour of the text slowly to the background colour according to the timer. --antilived^{T | C | G} 06:13, 23 August 2007 (UTC)

No, it would't work with Javascript in this instance. And the background isn't uniform.

In any case, I figured out what was going wrong. First thing is that dynamic text fields in flash don't let you apply filters (like adjusting the alpha) to them unless you embed all characters of the font.

Second of all, my stop() commands on the timers weren't working, and the way to guarantee that they worked was to instead issue them against event.currentTarget rather than the timer object variables.

Blah. So it all works now, after like, 5 hours of frustration! --24.147.86.187 11:29, 23 August 2007 (UTC)