Wikipedia:Reference desk/Archives/Computing/2008 October 8

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.

October 8

I have seup my own wiki, but I cannot edit any page (solved)

Hi, I'm trying to install my own wiki (here), and I have problem with editing pages. Installation was successful, but everytime I want to save changes to some page, I get following error:

Your edit has been rejected because your client mangled the punctuation characters in the edit token. The edit has been rejected to prevent corruption of the page text. This sometimes happens when you are using a buggy web-based anonymous proxy service.

I'm certainly not using any proxy service..I was searching for possible solution, but I couldn't find anything on MediaWiki pages nor Google. How could I solve this problem? Thanks for any advice! Lukipuk (talk) 02:35, 8 October 2008 (UTC)

Hmm, I seem to be able to edit it fine. Perhaps try a different IP address? 193.194.132.78 (talk) 07:08, 8 October 2008 (UTC)

Oh i changed the wiki engine from MediaWiki to DokuWiki and it works now, but thank you :) Lukipuk (talk) 13:49, 8 October 2008 (UTC)

Finding all IPs affected by a range block

Hello everybody, is there a tool or a website to find out which IPs have been affected if someone performs a range block? Thanks 211.30.12.197 (talk) 07:21, 8 October 2008 (UTC)

I don't see what the need for a tool would be. If it is a decimal system for defining the range, it is very obvious. If you block 192.168.1.25-98, it is obvious that everything from 192.168.1.25 to 192.168.1.98 will be blocked. Usually, a bit-mask is used. Something like 192.168.1.0/20 will use the 20 most significant bits of 192.168.1.0. Written in binary, that IP address is 11000000.10101000.00000001.00000000. I struck out all but the first 20 bits so you can see that any IP address that has those first 20 bits is blocked. They are sequential from 192.168.0.0 to 192.168.15.255. -- kainaw™ 13:04, 8 October 2008 (UTC)

Java Hashset look up

Given a class (Thing) with three members (mone, mtwo, mthree) I want some kind of Java Collection<Thing> that let's me

1) put objects in it, guaranteeing uniqueness of just mone and mtwo (ie mone and mtwo can't both be the same for two elements)

2) retrieve them by just mone and mtwo, in constant time for arbitrary mone, mtwo

Is there an obvious Collection to use?

Thanks —Preceding unsigned comment added by 194.223.156.1 (talk) 08:23, 8 October 2008 (UTC)

2) The problem with Sets is that they don't really have a "retrieve" functionality. The reasoning being, if you can tell it what you want to retrieve, don't you already have it? They didn't think about having different objects be "equal" and using one to retrieve another. One solution would be to use some kind of Map<Thing,Thing> that maps each thing to itself. Retrieval time complexity depends on the data structure used.

1) For this, you would just override the equals() method so that two objects are equal if their mone and mtwo are equal. Note that if you do that you also have to override the hashCode() method or else you would violate its contract and it wouldn't work in a hashed data structure. --Spoon! (talk) 09:45, 8 October 2008 (UTC)

So I could just have a Map<ThingSignature, Thing> where a ThingSignature has members mone, mtwo and each Thing has a getSignature() method and I add Things like map.add(thisThing.getSignature(), thisThing) —Preceding unsigned comment added by 194.223.156.1 (talk) 11:41, 8 October 2008 (UTC)

Or I guess skip the ThingSiganture class if I can figure out a simple return type like String for getSignature that would really be unique...... Hmm... —Preceding unsigned comment added by 194.223.156.1 (talk) 11:42, 8 October 2008 (UTC)

Tor

Are tor users allowed to edit wikipedia and create accounts? Are tor users blocked frequently by check users? I am considering to install tor that's why I wanted to ask. Thanks 59.95.116.34 (talk) 10:02, 8 October 2008 (UTC)

Anything else I can do to stay anonymous on wikipedia? 59.95.116.34 (talk) 10:04, 8 October 2008 (UTC)

Wikipedia:Open proxies and Wikipedia:Advice to users using Tor to bypass the Great Firewall contain all the answers to your first question. In response to your second question, what would you be trying to hide and from whom? -- zzuuzz ^(talk) 10:18, 8 October 2008 (UTC)

Thanks59.95.116.34 (talk) 10:24, 8 October 2008 (UTC)

[1] The only way to do that is to not edit abusively. -- zzuuzz ^(talk) 11:22, 8 October 2008 (UTC)

If you do that (edit abuseivly ) they call you an ADMIN. 99.185.0.29 (talk) 06:43, 10 October 2008 (UTC)--

Controllable animations...?

Hi. I am looking to make a 3D animation for a course I’m doing, using some kind of CAD/animation package. The caveat is that I’d like to be able to control the animation from a script that has a user interface. This would mean that, for example, the user could click a button to send the objects on the screen in different directions, all managed by a script.

CAD/modelling software I am familiar with include SketchUp, AutoCAD, Rivet and Blender (to an extent). Scripting languages I can use include Visual Basic, MATLAB and C.

Are there any suggestions as to how I could go about doing this? Many thanks.

LHMike (talk) 10:05, 8 October 2008 (UTC)

Blender can certainly do that. There is a game engine (of sorts) that comes with blender and can be scripted in Python. It's an opensource package - so it's free. However, if you have $$$ - then Maya or 3DS Max should be able to handle your needs.

Incidentally, FYI, you should distinguish "CAD" programs from other 3D modellers - CAD packages have very specific features such as the ability to deal with the volume, mass, center of gravity, etc of an object. Most 3D modellers for animations use some kind of "surface representation" which doesn't lend itself to the kinds of things CAD users need - but is easier for things like animation and rendering where you really don't care much about volumetric information. Blender is very definitely NOT a CAD program - AutoCAD certainly is (and it sucks for animation!). SteveBaker (talk) 03:24, 9 October 2008 (UTC)

Thunderbird On Mac

My Thunderbird keeps telling me I have mail, when I don't. This happens every couple of minutes, and it is driving me crazy. Is it supposed to do this? How can I set it so it tells me I have mail, when I actually have mail???--ChokinBako (talk) 11:04, 8 October 2008 (UTC)

Are you using it with an IMAP server? I've had issues with IMAP getting confused about what mail I've read (though with Mail.app, not Thunderbird). But really, I don't know, you need to give us more info about your setup. --140.247.11.23 (talk) 14:16, 8 October 2008 (UTC)

Do you have UNREAD messages, though? Kushal (talk) 15:44, 8 October 2008 (UTC)

Clarification: Do you have emails that arrived in your inbox that you never bothered to open? When I said UNREAD messages, I meant those messages. I did not mean messages that you read and then marked as unread. Kushal (talk) 20:39, 9 October 2008 (UTC)

Is it possible that it's notifying you of the arrival of a message - which is then immediately classified as spam and deleted or pushed off into another folder? I use Thunderbird - but I turn off the notification feature - so I'm not 100% sure what happens in those circumstances. SteveBaker (talk) 03:15, 9 October 2008 (UTC)

five advantages of open loop control system

May you list for us five advantages of the open loop contol system. —Preceding unsigned comment added by 196.44.166.203 (talk) 11:24, 8 October 2008 (UTC)

May you explain for us why the article open-loop controller doesn't answer your question? -- kainaw™ 12:57, 8 October 2008 (UTC)

And may you further explain for us why you expect us to do your homework, when it's clearly stated at the top that we do not do homework here? --Alinnisawest,^{Dalek Empress} (extermination requests here) 18:18, 8 October 2008 (UTC)

Making ringtones

Is there any sort of free music software that I can use to cut out the choruses of mp3 files so I can use them as ringtones for my phone? --Candy-Panda (talk) 12:00, 8 October 2008 (UTC)

Audacity is pretty good with that, Goldwave too

Forai (talk) 14:19, 8 October 2008 (UTC)

You may already be aware of this site, but you can crop any available ringtone on Myxertones as well as uploading your own MP3s. --Endlessdan and his problem 18:29, 8 October 2008 (UTC)

Or Audacity if you want to do it yourself. --antilived^{T | C | G} 07:22, 9 October 2008 (UTC)

Yup. I use Audacity, myself. The Jade Knight (talk) 07:40, 9 October 2008 (UTC)

InvisionFree or phpBB3?

Which Internet forum software is more reliable and less prone to security vulnerabilities and hacking attacks, InvisionFree or phpBB3? Thank you very much in advance. —Preceding unsigned comment added by XxCutexXxGirlxX (talk • contribs) 15:14, 8 October 2008 (UTC)

Securitywise, Going by the wikipedia articles phpBB and InvisionFree, If security is your thing then I would say phpBB3. InvisionFree article states:

"Limitations of InvisionFree include the lack of FTP access and editing restrictions and inability to access the MySQL database directly, lack of security as the software is remotely hosted." and while the phpBB article states it's been hit a few times, phpBB3 remains rather open. (Not to mention I run my own little php forum and it hasn't seen too many problems securitywise). Hope I have helped Forai (talk) 16:28, 8 October 2008 (UTC)

That "lack of security as the software is remotely hosted" is unsourced, and sounds like someone's opinion. It seems they're saying "it's less secure because it's hosted on someone else's server, rather than your own", that seems like a horrible over-simplification. It's like saying "gmail is less secure because it's hosted by Google rather than on a PC you set up yourself". -- Finlay McWalter | Talk 18:37, 8 October 2008 (UTC)

Fast DVD copier

Hi. Is anyone aware of a (preferably free) fast DVD copier (for un-protected DVDs)? I usually use Nero, but to copy a single movie disc it takes up to an hour. My friend has Roxio and it only takes him 15 minutes, tops. Are there any decent, free DVD copiers out there? Thanks in advance. --Endlessdan and his problem 18:27, 8 October 2008 (UTC)

Your friend probably has a faster DVD drive (or two). If all the copier has to do is read and write data (no recompression, no crypto) then the software does very little, and so all software should run at much the same speed on any given drive. -- Finlay McWalter | Talk 18:29, 8 October 2008 (UTC)

We have the same speed DVD-RW. The way he explained it (he gave me an extremely dumbed down explanation): Nero is slow because it takes the contents of the DVDs and dercrypts them (its already decrypted, this appears to be the unnecessary step), then takes the de-decrypted contents and places them on the DVD and then erases that copied content from its temporary memory. The Roxio program just goes DVD to DVD. I could be wayyyy off. But even copying a CD on Nero takes a long time. --Endlessdan and his problem 18:36, 8 October 2008 (UTC)

Decrypting is trivial (your CPU can decrypt a CSS stream much faster than any DVD can deliver it; if the media isn't encrypted there there is nothing to decrypt - you can't decrypt the unencrypted). If your drives really are the same, and your using the same media, then most likely you have Nero set to one of its more paranoid settings. Turn off speed testing, and the simulation/trial run thing, and turn off its error-correcting/retry on error option, and make sure it's detected your drive at its full speed and is set to use that. It's not that Nero is slow (Nero, at least in its retail version, is very highly regarded) but that it defaults to some rather paranoid settings. If you just can't persuade it to work faster, try Infrarecorder, which is free. -- Finlay McWalter | Talk 18:58, 8 October 2008 (UTC)

Now things are quite different if your copying a video DVD from a commercial version (which is almost always dual layer) down to a single-layer DVD-R. That way it can't just copy data from one disk to another, but has to decode the video and then re-encode it at a lower bitrate. Even on a good CPU that re-encode can take 30 minutes, which has to be done before the newly compiled (shrunken) DVD image to the blank DVD-R. -- Finlay McWalter | Talk 19:02, 8 October 2008 (UTC)

Ah, one thing to do is to download the absolutely latest patch of Nero from Ahead's website; because Nero fitters around with features of the drive much more than other programs, it really needs to know about your exact drive. If the drive is new and your Nero isn't super-updated then it may fall back to safer speeds. I've had Nero refuse to recognise a given drive is writable at all, when even XP's dullard cd-write subsystem could write to it. -- Finlay McWalter | Talk 19:15, 8 October 2008 (UTC)

Wow, thank you. I will try to mess with the settings and check Ahead's website tonight. Thanks again. --Endlessdan and his problem 19:50, 8 October 2008 (UTC)

Online shopping project

Hi, Can someone help to give me some intruction to do Online shopping project ? give me some outlines,etc..

likes

1. Decision Support Systems 2. Developing Business/IT Solutions 3. Enterprise and Global Management of Information Technology.

In conducting research and developing the paper, students are asked to address the following questions in their final analysis (paper): Define the topic of choice; how is the topic important in ensuring the success of the business/organization; what are some specific products (i.e. systems) relevant to the topic, used in a particular business or industry today; what aspects of the topic may change in the future (necessary to improve or enhance the services or products that it generates or maintains); what are some of these changes.

Thanks

—Preceding unsigned comment added by 24.98.233.164 (talk) 19:25, 8 October 2008 (UTC)

We would love to help you but we need to see what effort you have done so far. As you might know, we do not do your homework for you. We MAY help you with specific parts with which you have problem with, but for the most part, we allow you the opportunity to call your work your own. Kushal (talk) 19:47, 8 October 2008 (UTC)

Do you really mean online "shopping" or did you actualy mean online "selling"? Customers shop. They don't need business or IT solutions and have no need for IT technology above a web browser. As for decision support, that is nothing more than asking your buddy if he or she agrees with your purchase. -- kainaw™ 19:48, 8 October 2008 (UTC)

RealPlayer 11 on Ubuntu 8.10?

Resolved

I recently tried to install the .deb file of RealPlayer on a beta version of Ubuntu 8.10, but it did not worked... is it a problem from my computer, or some sort of other problem? can anyone install it? Thanks. SF007 (talk) 22:55, 8 October 2008 (UTC)

Can you give more details please? --wj32 ^t/c 03:33, 9 October 2008 (UTC)

I open the .deb file, click install, it starts downloading the dependencies, but than just "hangs", clicking the button to see the terminal shows some "404 not found" errors on what should be the dependencies links... SF007 (talk) 14:41, 9 October 2008 (UTC)

My guess is that the package archive mirror you are using is having some problems, so all packages aren't available at the moment. Try switching to the main archive or a different mirror near you by going to System -> Administration -> Software Sources. Then try installing it again. Reep (talk) 16:21, 9 October 2008 (UTC)

Just reloaded/updated the repositories and it just worked! thanks. SF007 (talk) 19:52, 9 October 2008 (UTC)