Monthly Archives: December 2013

Safely ejecting USB flash thumb drives in Linux

In Windows, we use safely remove devices when removing USB drives, as typical inexpensive flash drives write data quite slowly (less than 5MB/sec). This is because by default, Windows “write caches”, that is, Windows uses RAM to temporarily store files — making the copy/write operation appear done faster than it actually is. In Linux, the […]

Compiling Octave 3.8 for Ubuntu 12.04 – 13.10

Note: The octave stable PPA finally (Apr 20 2014) has Octave 3.8.1. https://launchpad.net/~octave/+archive/stable I would recommend the normal user on Ubuntu 12.04 to consider using the PPA above, it will be much easier than the manual process below. ——————————————————————————————————————– Download source: wget -P ~/Downloads http://ftp.gnu.org/pub/gnu/octave/octave-3.8.2.tar.bz2 Extract to directory: tar -C ~/Downloads -xvf ~/Downloads/octave-3.8*.tar.bz2 Prerequisites  (Ubuntu […]

Converting AVI to grayscale PNG for easier analysis/viewing

An example of a large pixel-count AVI is the Dahlgren et al 2013 article on auroral bursts. This was taken with a 2560×2160 Andor Neo sCMOS camera and this video has 351 frames. You can try this process to keep in a more widely-compatible MJPEG motion JPEG AVI format, or alternatively you can convert each […]

Cinepak videos in ImageJ

If someone has sent you an AVI file with Cinepak compression, you may find that ImageJ/FIJI and other contemporary software cannot read the AVI file. There are two plugins that attempt to address this for ImageJ: http://rsb.info.nih.gov/ij/plugins/jmf-player.html http://rsb.info.nih.gov/ij/plugins/jmf.html But I found neither of them to work for me on the particular AVI Cinepak video I […]

hamlib: Stopping/starting rigctld and rotctld via Bash script

Stopping rigctld and rotctld: #!/bin/bash # finds rigctl and rotctl PIDs and SIGTERMs them # Michael Hirsch RigPID=$(pgrep rigctld) RotPID=$(pgrep rotctld) if [[ -n $RigPID ]]; then echo “Stopping rigctld PID $RigPID” kill $RigPID fi if [[ -n $RotPID ]]; then echo “Stopping rotctld PID $RotPID” kill $RotPID fi Starting rigctld and rotctld: for Kenwood […]

Changing serial RS-232 COM port baud rate of Kenwood TS-2000 remotely

To change the baud rate of the Kenwood TS-2000 over the RS-232 serial COM port, you can do this locally or remotely. Locally, you go into menu 56, and select your baud rate. Hamlib/rigctl recommends using the highest possible baud rate i.e. 57600 baud. Then power cycle the radio. Remotely, look at the CAT EX […]

Which format to use for sharing USB flash thumb drives and USB HDD

I have found that EXFAT is the most convenient format for sharing files between Mac/Linux/Windows/Android. EXFAT is supported from Windows XP through Windows 8.1 and beyond. EXFAT is supported on Mac OS X from 10.6.3 and newer [1]. EXFAT is supported on Linux from CentOS 5 and Ubuntu 10.04 and newer. EXFAT is supported from […]

pdflatex error: epstopdf Output filename not allowed in restricted mode.

you may get this error if you include .eps files that are not in the same directory or a subdirectory of your .tex file. E.g. a file that is in a directory above or adjacent to your current level. The “fix” is to include the -shell-escape option in your pdflatex command. E.g. pdflatex -shell-escape myfile.tex […]

WSJT-X on Ubuntu

This is easy to install thanks to John Nogatch’s PPA: 1) sudo apt-add-repository ppa:jnogatch/wsjtx 2) sudo apt-get update && sudo apt-get install wsjtx 3) mkdir ~/.wsjtx && cd ~/.wsjtx 4) wget http://physics.princeton.edu/pulsar/K1JT/kvasd Then just type wsjtx to start WSJT-X program

Stop MATLAB high CPU usage on Idle (Windows/Mac/Linux)

For at least Matlab R2013a and R2013b, you may find that after opening the Matlab Help Browser (and even after closing just the Help Browser while keeping Matlab itself open), that Matlab uses 100% of one CPU core at about 25% duty cycle. You can try pasting this command into Matlab (it will persist, you […]