Skip to content

Category Archives: code

quick MacOS VNC and Subversion fixes

Just a quick couple of notes in this post. Two problems sucked a few hours of time this week, so it seems reasonable that they get pushed somewhere more visible for those with the best of Google-fu... connecting to a Mac VNC server from Linux and a weird "authorization failed" bug/oddity in subversion. Connecting to […]

matrix multiplication in mySQL

Background For a while now, there has been a need in a project of mine to perform a large-scale matrix multiplication. Here, large-scale involves the multiplication of a 2000x2000 square matrix with another matrix containing labels.  A simpler example is projecting a matrix containing a set of class features into a 2-d Cartesian space for […]

normalize flash playback speed using ffmpeg

Video is a great way to demo a new system or option.  As a world, we're moving to the availability of high-speed connections just about everywhere, but we're not there yet.  That means that you probably want to crunch down a 30M high-quality video you just generated into something more tolerable, like 5-7M.  I've found […]

zenphoto movie and ffmpeg tricks

Discussion Recently, I switched from gallery2 to zenphoto for a few reasons, which are of course biased by my experience with these packages. The development tends towards straight-forward and simple approaches; this tends to break apart more as legacy things are carried forward, which I feel might be the problem with gallery Nice set of […]

fast top-k similarity computation in matlab

When pre-computing a similarity matrix, there there is a large cost in both time and memory for computing pairwise similarity between every sample, O(N^2).  There are two main ways to slightly reduce the cost of either one of these demands... Approximate Hashing: Hashing projects a set of features into a lower dimensional representation while simultaneously […]