Category: Uncategorized

Python using NaN or None as sentinel

Sometimes I was forced to use NaN as a sentinel value, for example with the current version of Numba that can’t handle “is not None”. The summary is that comparing to None instead of NaN is over 100 times faster. This negates the advantage of Numba when you have to compare to sentinel values! Here’s […]

Intel Edison vs. Raspberry Pi: OpenCV2

Using a proprietary algorithm for static image analysis on images, and running the algorithm repeatedly, the Intel Edison is about 2.35 times FASTER than the Raspberry Pi, using only ONE of the TWO Intel Edison cores

Matplotlib: 3-D mesh wiregrid example

Some of the Matplotlib 3-D examples out there are a little out of date. Here is a minimal working example for the current version of Matplotlib 1.4 #!/usr/bin/env python from mpl_toolkits.mplot3d import Axes3D # this line must come before the next line! from matplotlib.pyplot import figure,show from numpy import linspace,meshgrid,pi,sin #for testing ”’ key point: […]

GoToMeeting.com Windows client under Wine / Linux

So far, the webcam doesn’t work, but the send/receive audio does work on a test call. I didn’t test receiving video. NOTE: in an actual conference, I wasn’t able to get sound, and so had to use a telephone. I have also seen problems with this for people using Windows and Mac at a large […]

Quote of the Day

Some think the Earth is spherical, others that it is flat and drum-shaped. For evidence they bring the fact that, as the sun rises and sets, the part concealed by the Earth shows a straight and not a curved edge, whereas if the Earth were spherical the line of section would have to be circular […]

Winetricks “voice had cried out in terror” error resolve

if you get a winetricks error like: wine cmd.exe /c echo ‘%ProgramFiles%’ returned a string containing the word ‘unknown’, as if a voice had cried out in terror, and was suddenly silenced. You can fix it by doing the following 1) backup your existing system.reg file by typing in Terminal: cp ~/.wine/system.reg ~/.wine/system.reg.bak 2) gedit […]

rigctl / hamlib with Kenwood TS-2000

On a modern PC, you may notice intermittent errors with the Kenwood TS-2000 , something like: read_string(): Timed out 0.2 seconds without reading a character. The solution seems to be making rigctl wait for the TS-2000 to catchup by using the hardware handshake–you need a “real” RS232 cable for this to work, with the correct […]

using FITSIO in Octave under Cygwin

Cygwin installs the minimal amount of packages necessary, so to do work with many programs, you must install the prerequisities. This is especially true when trying to read FITS files in Octave using the Octave-FITS package, which depends upon the CFITSIO library. Here are the prerequisities you’ll need (get them using the Cygwin Setup.exe program) […]

GraphicsMagick compilation options (with Octave)

The version of GraphicsMagick you have installed may be limiting you to 8-bit-per-pixel images. Often we have scientific data that is 16-bit-per-pixel images. You can compile GraphicsMagick for your system using the following options: ./configure –with-quantum-depth=32 –enable-shared –disable-static