## Sunday, May 25, 2008

### moved to wordpress

I'm in the process of moving this blog to wordpress, which has much better LaTex support. The new URL is wdjoyner.wordpress.com.

## Saturday, April 19, 2008

### latex on blogger test

This is a test following http://wolverinex02.googlepages.com/emoticonsforblogger2.

The latex code
$
\frac{\pi}{4} = \int_{0}^{1} \frac{dx}{1+x^{2}}
$

should display some latex code for pi/4. Cool! (Don't forget to use the compose window, not the "Edit Html" window.) Seems to only work for displayed equations.

Here is another test:

sage: x = var("x")
sage: integral(1/(1+x^2),x,0,1)
pi/4
sage: plot(1/(1+x^2),x,0,1)

The plot is below.

The (Hamming) weight enumerator polynomial \$A_C\$ is defined by

$
A_C(x,y) = \sum_{i=0}^n A_i x^{n-i}y^i = x^n + A_dx^{n-d}y^d+\dots +A_ny^n,
$

where

$
A_i = |\{c\in C\ |\ wt(c)=i\}|
$

denotes the number of codewords of weight \$i\$.
The support of \$C\$ is the set

$
supp(C)=\{i\ |\ A_i\not= 0\}.
$