Wikipedia:Reference desk/Archives/Computing/2007 December 14

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[edit] December 14

[edit] IP address not from here

Just wondering why the whois on this IP address shows as being from the States, while I am in Quebec, Canada. Thanks! —Preceding unsigned comment added by 206.24.48.1 (talk) 02:57, 14 December 2007 (UTC)

Well, it says it's owned by New Edge Networks, which is an American company. A whois lookup will just find who owns the IP, not necessarily where the system using it is actually located (though that could be in the States too, it may be a proxy). -- Consumed Crustacean (talk) 03:02, 14 December 2007 (UTC)

I guess where I work must be using some sorta proxy. If so, what kind would they use here, with a few hundred PCs? —Preceding unsigned comment added by 206.24.48.1 (talk) 03:10, 14 December 2007 (UTC)

Notice that the whois entry for that IP address covers the range 206.24.48.0 through 206.24.55.255, which is 2048 addresses. Depending on how those addresses are being used, they could be quite spread out. In most cases, updating the whois database to accurately reflect the location of each subnet would be more trouble than it's worth. --tcsetattr (talk / contribs) 03:22, 14 December 2007 (UTC)
A whois only returns the location of the owner of the network. You want an IP geolocation database. --ffroth 05:14, 14 December 2007 (UTC)
Another option that can often provide better geolocation results than whois is traceroute. When I traceroute to the OP's address, it gets to the Great Lakes region of the AT&T network before quitting. That is a bit better than the Nebraska address that whois provides. -- kainaw™ 13:30, 14 December 2007 (UTC)

[edit] PSPICE 9.1

is there no symbol available for polar capacitor in PSPICE scematics version 9.1 (student version)193.251.135.125 (talk) 07:41, 14 December 2007 (UTC)

If you just want schematics I suggest you to use Eagle (program). --antilivedT | C | G 10:51, 14 December 2007 (UTC)

[edit] Flip book

To add the functionality of a flip book to an ordinary book, I would like to insert small images on every second page. I'd prefer to do it in the original LaTeX file, but modifying the resulting PDF could be acceptable as well. Do you have ideas on how I could do this in an good way (without manual work for each image)? —Bromskloss (talk) 13:09, 14 December 2007 (UTC)

  • What a wonderful idea! Flip books are seriously underused on book edges. It's easy to think of lots of great applications, as below. --Sean 14:58, 14 December 2007 (UTC)

For a math textbook ...

... a John Conway biography ...

... a physics text ...

... a computer science book.


I like your ideas. My PhD thesis (yay, I got a position!) will be about dusty plasma experiments that have been filmed (looks like this). I think it would be awsome to actually include a few examples on the edge of the paper version! —Bromskloss (talk) 15:51, 14 December 2007 (UTC)
Hey, for fun I wrote some code to do this! If you save the code below as "flippy.pl" and invoke it with:
 perl -w flippy.pl  FILE  XOFF  YOFF
it will put every file it finds in the current directory with a name like "flip-book-page-PAGE_NUM.png" on page PAGE_NUM of FILE at XOFF paces from the left of the page, and YOFF paces from the bottom of the page, saving it into a file called flippy-FILE. So for a flip book, you could save each frame of your movie into an even-numbered image file, and run:
perl -w flippy.pl MyThesis.pdf 0 30
and it will put flip-book-page-30.png, flip-book-page-32.png, flip-book-page-34.png, flip-book-page-36.png, etc. onto the corners of the pages at the very edge horizontally and a little way up from the bottom. The changed version will be saved as flippy-MyThesis.pdf. I just tried it and it looked great! --Sean 16:34, 14 December 2007 (UTC)
#!/usr/bin/perl -w

use strict;
use PDF::API2;

@ARGV == 3 or die "usage: $0 PDF-FILE IMAGE_X_LOCATION IMAGE_Y_LOCATION\n";

my $pdf_fname = shift();

# Note: 0,0 is the lower left of the page
my $img_x = shift();
my $img_y = shift();

my $pdf = PDF::API2->open($pdf_fname);

foreach my $flip_image (<*.png>)
{
    if ($flip_image =~ /^flip-book-page-(\d+).png$/)
    {
        my $page_num = $1;
        my $page = $pdf->openpage($page_num);
        my $graphics_context = $page->gfx();
        my $image = $pdf->image_png($flip_image);
        $graphics_context->image($image, $img_x, $img_y);

        print "Added image: $flip_image\n";
    }
}

my $output_fname = "flippy-$pdf_fname";

$pdf->saveas($output_fname);
print "Saved flip book in $output_fname\n";
Ooo, nice. I didn't know perl had such PDF capabilities built in. I wonder if I could get them into the LaTeX document itself, so that text could be linebroken around it in case it doesn't fit entirely in the margin. —Bromskloss (talk) 17:10, 14 December 2007 (UTC)
  • I hate wrestling with LaTeX, so you're on your own there. FYI, you can turn the above video into a flip book as follows (this is all done on an Ubuntu Linux machine).
First save each frame of your video into a separate PNG file:
   mplayer -vo png BE3b-2.avi
You probably want it to print black-on-white, so reverse it from your video's white-on-black. We also scale it down a bit to fit in the margin:
   for i in 0*.png; do convert -negate -resize 50% $i n-$i; done
Then remove any junk from previous runs:
   rm -f flip-book-page-*.png
Then set the starting page for your flip book (we'll start on page 10):
   page=10
Then copy your flip images into correctly-named files:
   for i in n-*.png; do 
       ln $i flip-book-page-$page.png
       page=$(($page + 2))
   done
Then create your book with the flip images at the lower left:
   ./flippy.pl MyThesis.pdf 5 20
That's it. I just did it and it looks pretty good. You'll have to twiddle with the X an Y offsets and the scaling a bit. --Sean 17:15, 14 December 2007 (UTC)
Dear God! I wish I was intelligent enough to have even the very slightest idea of what all that is about ! —Preceding unsigned comment added by 88.110.51.242 (talk) 08:04, 16 December 2007 (UTC)

[edit] Coding issue

Hi. Could an experienced coder help out with a coding issue on a wiki using mediawiki software. The problem is described in detail here and the effects can be seen here. Thanks in advance. Tbo 157(talk) 19:23, 14 December 2007 (UTC)

The code on the sandbox is really hard to comprehend. Can you please provide a flattened (ie. not transcluded, everything's on the sandbox) version so I can use an editor for this? There are quite a bit of junk in the main page, did you use something like Word or Frontpage in creating the code? Also, are you the administrator? If you are you can add a few classes in the CSS to significantly reduce the clutter in the code on the main page. --antilivedT | C | G 22:23, 14 December 2007 (UTC)
I have asked the administrator of the wiki to comment on the various things you mentioned. Thanks. Tbo 157(talk) 23:05, 14 December 2007 (UTC)

[edit] Cannot connect to internet through wireless network connection.

Hey guys, A couple of days ago my laptop, which runs Vista basic, stopped being able to access the internet while connecting to a wireless connection. I have tried updating my wireless card driver and resetting the modem and router. The internet is definitely working because my regular computer is able to connect as well as my Xbox360(both of which are hardwired). I am open to suggestions because this is very puzzling to me and I am at wits end. Thanks, Z28boy (talk) 19:36, 14 December 2007 (UTC)z28boy

Are you sure your router is working? --Kushalt 21:01, 14 December 2007 (UTC)

Can you take the laptop somewhere else that has an available wifi connection? For example, a friend's house, coffee shop, or library? If you can connect there, then you know the wireless card in the laptop is working, and the problem is with your router. Otherwise, you'll know that the problem is with the laptop. --LarryMac | Talk 21:34, 14 December 2007 (UTC)

Thanks guys, but I fixed it myself, just a stupid mistake on my part! Z28boy (talk) 01:00, 15 December 2007 (UTC)z28boy

Was it because you pressed "FN"+"F2"?