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Basilisk II

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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

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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.

MoinMoin

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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

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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>
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