Follow me as I struggle with rogue technology, insane programmers, and impossible math questions in a battle to the death.

Tuesday, September 30, 2008

vdash - Math wiki of the future?

I saw this article on slashdot about vdash, a wiki for math proofs being built by Cameron Freer, a postdoc instructor of pure mathematics at MIT. The video of his talk for O'Reilly's Ignite Boston sums it up well.

The wiki does not appear to be open to the public yet, but he says in the video you can contact him to get involved in the prototype. According to the talk, any proof added to the site would be checked by a logical proof program (I assume Isabelle) to make sure that it is true. I wonder what the rejection process would look like. I assume there will also be humans in the loop doing moderation of the site, so I'm wondering who they'll allow to take part in that moderation.

Labels:

posted by Jacob Fenwick at 6:46 PM | 0 Comments

Reset auto increment for a table in MySQL

ALTER TABLE theTableInQuestion AUTO_INCREMENT=1234

That was easy. Someone posted the command in the comments for the Using Auto Increment page in the MySQL manual. I often find that the comments are more helpful than the manual.

Labels:

posted by Jacob Fenwick at 6:36 PM | 0 Comments

Fedora conquered

I finally ended up installing Fedora using the text based installer and it worked. It's also possible that the problem with the computer in the optics lab was due to errors in the install discs I was using since it said there were errors, but I find that unlikely since the second set of discs reported errors as well. I think that more likely the media tester and the graphical anaconda installer both have some serious issues.

In retrospect, I should have just used Ubuntu. I only chose Fedora because that's what the the people in the lab were accustomed to.

Labels: ,

posted by Jacob Fenwick at 6:33 PM | 0 Comments

Monday, September 29, 2008

Fedora is driving me insane

I've been trying to install Fedora Core 9 on an ancient computer in the Optics Lab at school and I'm experiencing all sorts of craziness. When the graphical installer gets to the end it says:

No kernel packages were installed on your system. Your boot loader configuration will not be changed.

What on earth could cause a linux distro to NOT install the kernel? It boggles the mind.

I've had this problem since last week and even posted on the Fedora Forums, so far to no avail.

Today I got the smart idea to run the media test on the cds I was using to install Fedora. The very first disc got registered as bad by 12% in. When I saw Fedora complaining about the disc I thought that it could either the ISO or the cd itself. I downloaded JSummer and ran it against all the ISOs and as far as I could tell they were all good. At this point I figured it had to be the cd and not the ISO so I tried burning it again, but the second cd failed in exactly the same place, so I started downloading a new copy of the 600+ meg ISO. By then I had to leave, tomorrow I'll burn the new download of the ISO and try it again.

Tonight when I got home I downloaded all the ISOs off bittorrent. I burned the discs and started an install on an old box that's been collecting dust in the corner. Before I started the installation I ran an SHA1SUM on the ISOs and they all checked out. When I ran the media check on the first disc it got all the way to 100% and then it said the disc had errors! I decided I didn't care and went ahead with installing anyways, but at some point during the installation of libraries from disc2 it bombed out on me.

So, either I downloaded bad ISOs both at work and at home and yet they still managed to get past SHA1SUM and burn the discs correctly, or, all the cds I'm using are bad. I find either of these possibilities unlikely. I think it's more like that the Fedora Core 9 graphical installer is just bad for anything but the latest and greatest computer.

Labels: , ,

posted by Jacob Fenwick at 10:39 PM | 0 Comments

Bug in colgroup tag in Firefox

I was working on a webpage where I needed to have an HTML table with an invisible column that I could make visible at will. To do this, I created a colgroup for the table that contained col tags, and I set the style of the col to display:none, which could be changed to display:visible with javascript.

When I tested the code, I found it worked correctly in IE7, but it didn't work in Firefox 3 at all!

Here is some code showing the problem:

<html>
<head><title>Bug in the COL tag</title></head>
<body>
<table border="1">
<colgroup span="3">
<col style="background:red"><col style="display:none"><col style="background:blue">
</colgroup>
<tbody>
<tr><td>hello</td><td>hi</td><td>goodbye</td></tr>

<tr><td>hello</td><td>hi</td><td>goodbye</td></tr>
<tr><td>hello</td><td>hi</td><td>goodbye</td></tr>
<tr><td>hello</td><td>hi</td><td>goodbye</td></tr>
<tr><td>hello</td><td>hi</td><td>goodbye</td></tr>

</tbody>
</table>
</body>
<html>

I submitted the bug to Mozilla, so hopefully someone takes a look at it.

Labels: , ,

posted by Jacob Fenwick at 12:31 PM | 1 Comments