Wikipedia:Reference desk/Archives/Computing/2009 February 19

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February 19

Dell Inspiron 5100 Processor

I just cleaned all the dust out of my Dell Inspiron 5100 processor fan and heat sink. I had been getting increasingly bad performance during even mildly CPU-intensive activities, during which the CPU would go to 100%, and the air coming out of the fan area was noticeably hot. The Dell 5100 has had plenty of overheating problems. I suspect it wasn't too wise to put (what I think is) a regular P4-2.6Ghz processor in a laptop.

Anyway, I installed the Dell Inspiron temperature management software after the cleaning. I'm watching the temperature closely.

My question is: In what temperature range should the P4 (again, I'm not sure this is a regular P4, I only think so. I don't think it is the P4-M.) be operating? At what temperature does it slow itself down to prevent further overheating? Is there any harm in setting my fan utility to always blow at 100% (the computer's original BIOS doesn't seem to step it up to 100% often enough to properly manage the temperature)

Also, the wireless card on the computer is getting old. I constantly lose my connection and have to release/renew to get it going again (even though the signal strength remains high and there exists no apparent indication of a problem by looking at the wireless utility in the system tray. Also, drivers are up to date). Because of this, I often leave a non-stop ping going to google.com to indicate whether or not I have a connection. Is there a little utility that will run in my system tray that will indicate whether or not I have a good ping to some URL?

Thanks (PS - as I was posting this, I lost the connection again...)NByz (talk) 02:28, 19 February 2009 (UTC)

The thermal management threshholds vary from processor to processor (not just from series to series). Each one is individually calibrated before it ships. About two years ago I did some tests with a P4 1.7Ghz + heatsink and passive ventilation only, and it began throttling at about 60C, and shut itself down at 120C. YMMV of course.

Your sporadic WLAN problem sounds more like radio interference. Garage door? Babyphone? Evil neighbour with a Jacob's ladder? -- Fullstop (talk) 19:14, 19 February 2009 (UTC)

Thanks! I've set the processor fan to go to 100% at 50 degrees. I don't mind the noise, and I don't suspect it will hurt it to be on more often..? It really feels like it starts slowing down at around 55 or 60 degrees.

It could be interference on the wireless card. The thing is, it happens pretty regularly (about once per hour) regardless of what's going on. I also have five other computers using the same wireless network in this house that don't have the same problem. NByz (talk) 19:46, 21 February 2009 (UTC)

I think my friend has a 5100, and yeah, it runs hot. Running the fan more often will wear the fan down a bit more, but that's not something to worry about, realistically. As for your wireless issue, it could be a slight incompatibility with the router. I have solved similar problems by assigning an IP to the device MAC address, using the router config. Just a suggestion. - mako 02:02, 22 February 2009 (UTC)

If your friend hasn't popped off the keyboard and cleaned out the fan casing and heat sink yet, he should give it a try. It has really helped the heat handling. Instructions can be found on google pretty easily.NByz (talk) 03:04, 22 February 2009 (UTC)

protecting online images

Is there a straightforward way to prevent exposure of image folders on web sites? If you type http://[sitename].com/images on my (inexperienced) friend's site, you get "Index of /images" and access to everything that's there (including parent directories). But I have seen "Forbidden" on other sites. How can I help her make her image folder forbidden? Thanks! --Halcatalyst (talk) 03:51, 19 February 2009 (UTC)

With Unix permissions, one simple trick is to deny read permission bit for "other" (people not in your group, which includes the web server program) for the directory. Like 0751 (r-xr-x--x) or 0711 (r-x--x--x). Without the read permission, they won't be able to list the directory, but will still be able to access everything inside, provided that execute permission is granted.

A more proper way to do it would be to place Options -Indexes in a .htaccess file in the directory. You can of course, always upload any index.html file (either blank or displaying some message of your choosing) and that will do the trick too. --164.67.206.11 (talk) 04:17, 19 February 2009 (UTC)

As 164.67.206.11 said, A less proper (but easier) way to do it is to put an html file in the directory with one of the "standard" names—index.html, index.htm, default.htm, etc.—so the webserver will return that page instead of an automatic index. The file can be blank, or have a "Forbidden" message, or auto-link back to the webpage, or whatever. Again, this isn't the "correct" way to prevent indexing, but it tends to be the easiest. – 74  04:26, 19 February 2009 (UTC)

That sounds like it ought to be easy to subvert at the client end. Is it? Algebraist 15:52, 19 February 2009 (UTC)

No, there is no way to subvert it. --76.167.241.45 (talk) 20:30, 19 February 2009 (UTC)

A good security practice is to turn off directory indexes for the whole site, and then selectively enable it on particular directories if desired. --Sean 13:29, 19 February 2009 (UTC)

Copying a website

Is it possible to download or copy a whole website ?If yes, are there special softwares for this purpose ? the whole procedure ? Thanks —Preceding unsigned comment added by 201.220.215.12 (talk) 04:46, 19 February 2009 (UTC)

You might want to take a look at HTTrack; it even has an online tutorial. – 74  04:52, 19 February 2009 (UTC)

wget -r ... --76.167.241.45 (talk) 06:18, 19 February 2009 (UTC)

You'd better read more of the wget docs before you start using wget, otherwise you might find it downloading gigabytes more than you want. It's a good program, designed for people willing to read and think. Morenoodles (talk) 09:55, 20 February 2009 (UTC)

Video conversion software

I want a free software that i can download off the internet that will convert video files to be played on my ipod. iTunes does convert them, but i get no audio on the converted files. Thanks. —Preceding unsigned comment added by 116.71.58.66 (talk) 15:49, 19 February 2009 (UTC)

What format are the videos in? Algebraist 15:50, 19 February 2009 (UTC)

They are in MPEG and WMV formats. —Preceding unsigned comment added by 116.71.58.197 (talk) 12:55, 20 February 2009 (UTC)

For YouTube videos>iPod format, you can use this. --KageTora (talk) 19:57, 19 February 2009 (UTC)

Avidemux, SUPER, MediaCoder, HandBrake, megui SN0WKITT3N 20:28, 19 February 2009 (UTC)

Toshiba Satellite L350 laptop -- Is the memory dual-channel?

Toshiba Satellite L350 laptop -- Is the memory dual-channel? The webpage does not give this detail. I searched the web with Google but could not find any reliable information. Is there something in the specification that implies that this laptop is dual-channel? Or could someone who has any recent Toshiba Satellite let me know? Thanks! --Masatran (talk) 16:02, 19 February 2009 (UTC)

According to the detailed product specification, it uses PC6400 DDR2 SDRAM. I believe that this is dual channeled. - Akamad (talk) 02:53, 20 February 2009 (UTC)

MATLAB: is it possible to selectively save only one output variable from a multi-output function?

If one has a MATLAB function along the (generic) lines of [a,b,c,d] = f(x,y,z), is there a way to evaluate the function and save only one of the output variables?

For example, if the function above is called in the following manner:
[a,b,c,d] = f(x,y,z)
variables 'a', 'b', 'c', and 'd' will all be saved.

However, if the function is called like this:
q = f(x,y,z)
only the output variable 'a' will be saved.

Is there a way to have behaviour analogous to the second case, but for other output variables besides the first one? (For example, save only variable 'b' or 'c'?) —Preceding unsigned comment added by 128.100.36.234 (talk) 16:24, 19 February 2009 (UTC)

You can save all four variables to temporary variables and then delete them using the clear command.

 [temp_a,temp_b,c,temp_d] = f(x,y,z);
 clear temp*   % or explicitly clear temp_a; clear temp_b; clear temp_d;

This will result in only c being stored. Nimur (talk) 16:42, 19 February 2009 (UTC)

Algorithm Wanted

What I want to do is accept a double-dimensional array’s elements from the user, then find out the combination of elements (no two of which are in the same column)which have the minimum possible sum. Can anyone suggest an algorithm for this? Thanks in advance. La Alquimista 17:58, 19 February 2009 (UTC)

If I understand you right, the minimum possible sum would be the sum of the two smallest values. :Assuming that the elements are unsigned integers, and that neither dimension has more than 64K elements,...

unsigned array[5][10]; /* 5x10 array to search */

unsigned minval[2] = {UINT_MAX, UINT_MAX}; /* slots for the smallest two values */

unsigned minpos[2] = {UINT_MAX, UINT_MAX}; /* for position in the matrix */

unsigned r, c;

for (r = 0; r < ((sizeof(array)/sizeof(array[0]))/sizeof(array[0][0])); r++) {

for (c = 0; c < (sizeof(array[0])/sizeof(array[0][0])); c++) {

if (array[r][c] < mival[1]) {

minval[0] = minval[1];

minpos[0] = minpos[1];

minval[1] = array[r][c];

minpos[1] = (r << 16) | c;

}

}

}

printf("Minimum possible sum: array[%u][%u] + array[%u][%u] => (%u + %u) => %f\n",

minpos[0]>>16, minpos[0] & 0xffffu, minpos[1]>>16, minpos[1] & 0xffffu,

minval[0], minval[1], ((double)(minval[0])) + ((double)(minval[1])) );

That's off the top of my head, but should be ok I think. -- Fullstop (talk) 18:53, 19 February 2009 (UTC)

I don't think they wanted to limit the sum to just two values, but probably one from every column. This would still be trivial, just find the minimum value in each column and sum those. I suspect there's another part they didn't mention, though, like that no two values can be used from the same row, either. This would make it into a challenging computer problem. Since the user probably can't enter all that many values, I'd suggest a brute force approach here of trying every possible combo and taking the lowest. A more elegant solution is also possible, but not likely to be necessary for such a small amount of data. For 100 values in a 10×10 array, for example, there would be 10 billion possible combos to try, but most of those would be eliminated because they shared a common row. Only 10! (3,628,800) would need to be summed (and, even then, you could abort any trial as soon as it's total exceeded the minimum so far). StuRat (talk) 20:47, 19 February 2009 (UTC)

I guess I forgot to mention a few details... Ok, so, rules: The array is a square matrix, and the maximum size for my program is 6. One and only one number (neither more, nor less) can be taken from each row. The same goes for each column as well.Quite obviously, the output should remain the same even if the order of the rows are scrambled. For example take the following matrix:

 12 23 5

 5 12 23

 2 15 12 

The output should be:

1st Row: 5

2nd Row: 12

3rd Row: 2

Minimum possible sum: 5+12+2=19 La Alquimista 06:53, 20 February 2009 (UTC)

I suppose you've figured out that the obvious greedy algorithm will not work. This is a common example of a problem easily solved with recursion - although it is normally the goal to get a certain value given an array of possible units: ie, given 1 3 5 9, create 72 using the minimum number of 1's 3's 5's or 9's. For you, the algorithm is very straightforward. For each element of the first array, try using each element of the next array with each element of the last array. If the set is invalid, don't consider it. If it is valid, check the sum. If it is lower than the best sum you've previously found, that set is your current best set. -- kainaw™ 07:12, 20 February 2009 (UTC)

I guess that'll work fine for an array of size 3. But what about the bigger ones?? The number of nested loops will become way too cumbersome then, don't you agree?? La Alquimista 07:42, 20 February 2009 (UTC)

You wouldn't be looking for the Hungarian algorithm would you? yandman 08:12, 20 February 2009 (UTC)

Wow!!! It is what I wanted!! Thanks a bunch!! La Alquimista 08:27, 20 February 2009 (UTC)

Also see recursion. There are no "nested loops" as you mentioned. It is a function that calls itself. -- kainaw™ 15:34, 20 February 2009 (UTC)

Firefox issue, probably me being an idiot

My friend was using my laptop, and then when I got back on it, it appears that a text-cursor like flashing bar appears at the end of every line or box I click on, almost like in a text editor. I think this has happened before, but I've completely forgotten how to turn it off. Any ideas? I'll screenshot if anyone needs it. Thanks :) —Cyclonenim (talk · contribs · email) 18:58, 19 February 2009 (UTC)

Tools --> Options... --> Advanced --> Always use the cursor keys to navigate within pages. Hermione1980 19:06, 19 February 2009 (UTC)

Thank you :) —Cyclonenim (talk · contribs · email) 19:12, 19 February 2009 (UTC)

Acer Aspire One

Do all Acer Aspire One come with Linux? My friend has one, and hers is dual boot Linux + WinXP. She said mine should be, too, but I can't get it to boot into Linux or anything because the 'press F12 for such-and-such' screen is only on for a split second - not even long enough for me to press anything. Anyway, question is, do they all come with Linux? If not, then I will just assume I only have XP, because I can't be bothered testing my reactions with the 'F' buttons.--KageTora (talk) 19:42, 19 February 2009 (UTC)

Can you tell us the model number of your computer? If it ends in L, or A followed by a letter standing for the colour, then it should have a light version Linux installed. If it ends in X or B followed by a letter standing for the colour, then it has only Windows XP. —Cyclonenim (talk · contribs · email) 20:58, 19 February 2009 (UTC)

By the way, I got the above from our article: Acer Aspire One. —Cyclonenim (talk · contribs · email) 20:59, 19 February 2009 (UTC)

No I have a Linux version and that comes only with Linux. When I went to buy it (a month ago) you could have XP or Linux but not both. I have not heard of a dual boot one out of the box. Having said that, if you want to, why not just install linux anyway? (assuming you have the hard drive version) Theresa Knott | token threats 09:32, 20 February 2009 (UTC)

In Windows Vista, say you're downloading a file from a filesharing service, one click hosting...

Say it's a big file, and you need to go out but you also need to lock your computer so other people cannot tamper with your stuff, but the file is still downloading. If you lock the computer with password protection, sometimes, especially after a period of time, the file will fail to have downloaded, will just stop, by the time you get back onto the computer. What can be done about this?

Is there a program you can run to change this? (Having said that, you could just go Ctrl+Alt+Del and get around it... if such a program even exists.)--AbilityAgility (talk) 22:08, 19 February 2009 (UTC)

No program will continue to run if Windows decides to suspend/hibernate, but you can adjust the power management settings to prevent this (and some programs specifically prevent power management triggers). Other than that, you might want to look for a download manager with "Auto-Resume". This probably won't help much if the site you are using doesn't support download resume, however. – 74  23:56, 19 February 2009 (UTC)

Printing excel spreadsheet page: want guide marks for ring-binder hole-punch

I have created a paper form using a small one-page Excel spreadsheet. Is it possible please to get guide marks included on the left margin of the printed sheet to help with aligning a two-hole-punch for use with a ring-binder? How is it done? And, while I'm here, what about guide marks on the left margin in MS Word to help folding a letter into three? 78.147.141.29 (talk) 22:36, 19 February 2009 (UTC)

I don't know of any feature to do this directly, but you can insert autoShape circles (Insert→Picture→AutoShapes on older versions of Excel) and place them such that they serve as guide marks. This will require some amount of trial-and-error, but in the case of a commonly-printed form it might be worth the effort. Similarly, AutoShape lines can be inserted into a Word document, although again I wouldn't bother unless it's a form letter likely to receive frequent use. – 74  23:04, 19 February 2009 (UTC)

Sound file conversion

I have some .wma files on my computer that I can listen to on Windows Media Player. Is there any way possible I could convert them to .mp3 so I can have them on iTunes and put them on my iPod? They're useless to me otherwise, so I'll really like to be able to convert them. Illegal is okay. Thanks! Reywas92^Talk 23:02, 19 February 2009 (UTC)

Perhaps this page might provide some useful information. – 74  23:12, 19 February 2009 (UTC)

Thanks! I can be so computer illiterate sometimes! Should have known that it was easy and legal. Reywas92^Talk 23:15, 19 February 2009 (UTC)

If the files contain DRM (and if you are in the United States) then circumventing the DRM *is* illegal according to the DMCA (but often still easy). – 74  23:29, 19 February 2009 (UTC)

I can list a few more offline apps that do this, but it seems like you got what you wanted. http://mediaconverter.org might be of interest to you though. -- penubag  (talk) 05:19, 20 February 2009 (UTC)

Users

Are there any Wikipedia users who, these days, only or mainly use an older version of Windows? I know there are some - by clicking on the images in User:Google box - but 1) some of those users don't edit anymore or 2) some of those users now use a new version of Windows and haven't bothered to update their page. So are there any such users right now? JCI (talk) 23:26, 19 February 2009 (UTC)

Depends on what you mean by "older version". I edit mainly from Windows XP, which, since the release of Windows Vista, is technically an older OS. If you mean Windows 95 or (heaven forbid) MS-DOS, I don't know. Out of curiosity, why are you asking? Hermione1980 23:31, 19 February 2009 (UTC)

Because of the relatively small number of users who use older versions of Windows these days. And slightly off-topic and as a second question: how many, in numbers, copies of each version of Windows are in use today? JCI (talk) 23:39, 19 February 2009 (UTC)

My old computer still uses Windows 97 98 [sorry, just a typo], and I won't update it. I usually don't use it anymore because it has some severe issues... but if my current computer should suddenly have more severe issues/die completely, why not? --Thanks for answering (talk) 03:13, 20 February 2009 (UTC)

I almost always use my Windows 98 machine to edit Wikipedia, as I am right now. StuRat (talk) 04:15, 20 February 2009 (UTC)

I sometimes use Windows 2000. I haven't even heard of "Windows 97", which somebody above claims to be using. I don't see how anybody could possibly calculate how many copies of each version of Windows (or almost any other kind of software) are in use today. Morenoodles (talk) 09:52, 20 February 2009 (UTC)

Your comment (and Thanks's typo) inspired this graph investigating the frequency of "Windows X". – 74  16:15, 20 February 2009 (UTC)

Until 2007 I was using windows 98 SE to edit, but it had trouble with unicode, and trashing the IW links. Now with Windows XP. Graeme Bartlett (talk) 21:52, 20 February 2009 (UTC)

Not a representative sample (I get more Linux visitors than the Internet as a whole), but from my website's 2008 visitors:

• Windows XP: 60%
• Windows Vista: 15%
• Windows 2000: 4%
• Windows 98: 2%
• Windows Server 2003: 2%

I've also got hits from people running Windows NT (presumably 4), Windows 95, Windows CE, and Windows ME. The numbers from 2009 are still too small to tell for certain, but there seems to be a slight drop in the number of people using Windows Vista, and a corresponding increase in MacOS users. --Carnildo (talk) 22:47, 20 February 2009 (UTC)

I have a working windows 3.11 workgroups which can access the internet and could edit wikipedia, though I don't use it. Windows 98 and 2000 seem likely to be the oldest people are using on a regular basis though one or two people using windows 95, perhaps in places where better computers are unavailable, wouldn't surprise me either

No bullshit, free program that converts .flv to .wmv with good quality and no setbacks?

I've been unable to find one. Replay Converter only does 90 seconds in demo mode.--AbilityAgility (talk) 23:45, 19 February 2009 (UTC)

Also, if a QuickTime to .wmv converter exists, I'd like to know about that too, although it's of lesser importance.--AbilityAgility (talk) 00:00, 20 February 2009 (UTC)

You could give SUPER a try. I'm pretty sure I've used it for Flash Video. The download link is at the bottom of this page. Cycle~ (talk) 01:52, 20 February 2009 (UTC)

Seen it before, but why do you have to take all these unusual measures just to download a link? Seems to be a bit suspect to me. Is it available on rapidshare or anything, which would be more normal?--AbilityAgility (talk) 02:30, 20 February 2009 (UTC)

SUPER is a disgusting piece of software. What I mean by that is the horrible GUI - cluttered menus with 20 or so menu items, an over-complicated main window, and an author who is too proud of his software. Anyway, I'm sure VirtualDub combined with Combined Community Codec Pack will do the trick. --wj32 ^t/c 10:15, 20 February 2009 (UTC)

I know that you probably use Windows, but if you continue have problems, you can consider searching for a Windows port of ffmpeg. In Linux, converting flv to wmv is rather simple: "ffmpeg -i video.flv -vcodec wmv1 -acodec adpcm_ima_wav video.wmv" -- All that vcodec and acodec stuff is rather redundant and used to just to ensure that it encodes in simple wmv that everyone can play instead of some weird wmv that only runs on certain players. -- kainaw™ 15:27, 20 February 2009 (UTC)