Archive for January, 2011

Free Continuing Education Video Courses

If you are interested in following free continuing education courses (in topics like math, physics, biology, etc.), these might be interesting:

http://www.khanacademy.org/

http://www.youtube.com/user/nptelhrd

Friday, January 28th, 2011 Uncategorized No Comments

Constraint solving library

If you’re facing a problem concerning optimization of variables adhering to some constraints there are existing constraint programming toolkits.

An interesting library for C++ and python is the Operations Research Toolset by Google.

A python example which shows all combinations of variables a,b,c,d where a==b and c==d could look as follows:

  a = s.IntVar(0, 5, "a")
  b = s.IntVar(0, 2, "b")
  c = s.IntVar(0, 5, "c")
  d = s.IntVar(0, 999999, "d")

  all_vars = [a, b, c, d]

  #Constraints
  s.Add(a == b)
  s.Add(c == d)

  s.NewSearch(
    s.Phase(all_vars,
      s.INT_VAR_DEFAULT,
      s.INT_VALUE_DEFAULT)
  )

  while s.NextSolution():
    print all_vars
  s.EndSearch()

The output would be:

[a(0), b(0), c(0), d(0)]
[a(0), b(0), c(1), d(1)]
[a(0), b(0), c(2), d(2)]
[a(0), b(0), c(3), d(3)]
[a(0), b(0), c(4), d(4)]
...
Monday, January 24th, 2011 Uncategorized No Comments

Free profiling tools for windows

Some interesting free profiling tools for Windows:

Tags: , ,

Monday, January 24th, 2011 Uncategorized No Comments

Changing boot order Windows/Linux in GRUB2

By default, the installation provides a GRUB 2 that is configured to first probe for Linux OSs and then only for other OSs. A simple yet quite robust way of changing the order to Windows first and then Linux is the following:

Open a terminal and issue the following commands:


cd /etc/grub.d

sudo mv 30_os-prober 09_os-prober

sudo update-grub2

These commands will make sure thatr the os-prober script (which probes for other OSs, such as Windows) is executed before the script that probes for Linux OSs when automatically building the grub.cfg file.

Monday, January 10th, 2011 Linux, Ubuntu 10.10 No Comments

Extracting files from executable installers

A tool called Universal Extractor can be used to extract some types of executable installers. It does not  support everything, but a bit more than normal archivers.

This can be particularly useful when you want to run an application that requires administrator rights to install.

Tip: Use the Binary package of Universal Extractor if you do not have administrator rights.

Friday, January 7th, 2011 Uncategorized No Comments