You are here


Basilisk II

My old 68030 based Macintosh LC III in its bodily form is gathering dust upstairs, but its spirit lives on through an extraordinary emulator called Basilisk II. I just got around to porting the LC III's partition images from my old dell box to the new core 2 box and am pleased at how well it runs. Despite the LC III application software being totally obsolete, it is still quite functional and fast --- very very very fast.

Using a Wysiwyg Input

This is my first post using a wysiwyg editor through drupal.  All my previous attempts to use wysiwyg have been horrible so I have never tried it on this blog, but the new wysiwyg API fro drupal is a very good first step to getting things working better.


I am quite happy with the MoinMoin site I set up last week, but naturally not a sole is using it. I wonder why I bother to do this. It wasn't very hard to do, if a little time-consuming up-front trying to wade through the documentation for the half-dozen or so wiki's I was evaluating. I set up the dirt simple cgi script which is needlessly wasteful of cpu cycles but much easier on brain cycles.

A Dirt Simple Algorithm for a Reflexive Generalized Inverse


let A be a m by n matrix considered as a list of columns
construct B, an n by m matrix (considered as a list of rows), by elimination
such that BAB = B, ABA = A and AB an orthogonal projection onto the image of A

in exact artihmetic and pythonesque psuedo-code:

B = array(A)
for k,a in enumerate(A):
    v = B[k] # pivot row
    va = inner(v,a)
    if va: # note that v nonzero if and only if va positive
        v *= 1/va # scale on <a>
        for j,b in enumerate(B):
            if j == k: continue
            b = b - inner(b,a)*v # elimination on <a>
Subscribe to RSS - computing