IDL IDE (idlde) on Ubuntu 14.04 KDE desktop

I had the SIGSEGV error about libgobject-2.0.so.0 when running idlde from Terminal with KDE desktop on Ubuntu 14.04.

Following this procedure, from KDE desktop, I click the lower left “start” button on the desktop toolbar, go to “system settings” (you can start typing it in the start menu and it’ll come up) and make the following changes to get rid of the Oxygen theme.

  1. Style – Applications – Widget Style – Cleanlooks
  2. Icons – Theme – Humanity
  3. GTK – GTK Themes – GTK2 Theme – Ambience (also GTK3 Theme- Ambience).
  4. GTK – Icon Themes – Icon Theme – Humanity (also Fallback Theme – Humanity)

Now idlde ran without crashing for me.

Google Earth on Ubuntu 14.04

Even if your system is 64-bit, you should use 32-bit Google Earth at this time.

On some installs, typing in terminal
google-earth
gives the error
./googleearth-bin: error while loading shared libraries: libfontconfig.so.1: cannot open shared object file: No such file or directory
and libSM.so.6, etc.

This is remedied by typing:

sudo apt-get install libfontconfig1:i386 libX11-6:i386 libxrender1:i386 libxext6:i386 libsm6:i386

If you get errors about libGL.so.1, try:

sudo apt-get install libglu1-mesa:i386 libgl1-mesa-glx:i386

If you still get errors about libGL.so.1, try:

find /usr -name "libGL.so.1"

let’s assume you found it in /usr/lib/i386-linux-gnu/mesa
Then type

ln -s /usr/lib/i386-linux-gnu/mesa/libGL.so.1 /usr/lib

Enabling extra apt-get software/apps on Beaglebone

By default, the Beaglebone Black with Debian as of this writing doesn’t have packages like python-scipy in the repositories. This is simple to fix by enabling the “backports” repo as follows.


sudo nano /etc/apt/sources.list

and uncomment the line

deb http://ftp.debian.org/debian wheezy-backports main contrib non-free

then type

sudo apt-get update

Note: Some of the Python packages might be of versions older than you’d like (e.g. Scipy 0.10). You can try the pip install method in those particular cases.

Fixing Beaglebone Black Rev. C error on apt-get

I experienced an error upon any use of apt-get with a new Rev. C Beaglebone with the factory Debian install.

The error was like:

insserv: Starting led_aging.sh depends on rc.local and therefore on system facility ` $all’ which can not be true!
Here was the fix by replacing /etc/init.d/led_aging.sh with:

#!/bin/sh -e
### BEGIN INIT INFO
# Provides: led_aging.sh
# Required-Start: $local_fs
# Required-Stop: $local_fs
# Default-Start: 2 3 4 5
# Default-Stop: 0 1 6
# Short-Description: Start LED aging
# Description: Starts LED aging (whatever that is)
### END INIT INFO

x=$(/bin/ps -ef | /bin/grep “[l]ed_acc”)
if [ ! -n “$x” -a -x /usr/bin/led_acc ]; then
/usr/bin/led_acc &
fi

installing wine on ubuntu 14.04 after upgrade from ubuntu 12.04

I had the issue a few others had where trying to install WINE on an Ubuntu 14.04 x64 system that had previously been upgraded from Ubuntu x64 wouldn’t work with a message about liblcms2-2 conflicting with liblcms2-2:i386. Even the Wine PPA wouldn’t help.

Then I ran across a fix where you type
sudo apt-get install liblcms2-2=2.5-0ubuntu4
and then you can install wine!

Armchair commentary on Raspberry Pi 2 release

I applaud the Raspberry Pi 2 with ARMv7 quad-core CPU and LPDDR2 RAM release. My opinion on the original Raspberry Pi (non +, model B 256MB and 512MB RAM) boards was fairly sour due to the anemic ARMv6 single core CPU. Generally speaking, the Beaglebone Black and Intel Edison have been substantially better choices for the maker and professional embedded systems designer.

The Beaglebone Black has been a much better choice than the Raspberry Pi due in part to the PRU, DDR3L RAM (faster), and ARMv7 CPU.

The Intel Edison has been a much better choice than the Raspberry Pi and in some applications better than the Beaglebone Black due to the Edison’s dual-core x86 CPU, fast RAM, and extremely favorable energy efficiency. Depending on your application, the Edison may run 10x as long or more on battery than the Raspberry Pi (1 or 2) and Beaglebone Black.

I am awaiting side-by-side comparisions of the new Raspberry Pi 2 on benchmarks with the Phoronix Test Suite next to the Beaglebone Black and Edison to say more. I don’t plan to purchase a Raspberry Pi 2 at this time to do OpenCV benchmarking, but would be glad to hear if someone else does this benchmarking.

Importing old OpenCV modules from OpenCV 2 in Python on Windows

Some of the legacy modules like Horn Schunck Optical Flow in OpenCV 2.4 are located in “cv” instead of “cv2″ .

To be cross-platform compatible, instead of doing


import cv,cv2

I suggest doing

import cv2
from cv2 import cv

—————————————————-

Further, in Windows running Anaconda Python 2.7 (or whatever Python 2.7 you choose), OpenCV is not installable through conda.

To install OpenCV 2.4 for Python on Windows, do the following:

  1. From

    http://opencv.org/downloads.html

    download OpenCV for Windows, version 2.4

  2. Extract to a directory of your choice, let’s say c:\opencv and copy the file
    c:\opencv\build\python\2.7\x64\cv2.pyd
    to
    c:\Anaconda\Lib\site-packages\

If you’re using CPython instead of Anaconda, copy to that directory instead.