Unix-related Resources

Perl Scripts

  • Perl Script for Generating User Lists ( for CSci faculty)
  • Perl Script for Selective File Renaming
    This is a very useful little script. How often have you wanted to rename all of the files in a given directory in some uniform way, such as to add a prefix or suffix to each name, or replace blanks in names of files you got from some Windows system by underscores? What about replacing parts of the names of files? There is no way to do these things with any command in the shell. This script comes to the rescue.

Scientific Visualization

The following links are related to quantum mechanics and physics.

  • Java Visualization of Quantum Tunneling
    This is a Java application, not a Java applet. To run it, you will need Java 1.5 or higher. In Linux, you will need the Java Web Start executable (javaws), and the Java runtime. Tell the browser to open it with javaws. This application displays the wave functions, probability densities and wave packets for various barriers, and is fully configurable.
  • Paul Falstad's Math/Physics/Engineering Java Applets
    A great site containing Java source and executables for visualizing dozens of scientific problems, including, in particular, quantum mechanical problems such as the hydrogen atom, harmonic oscillators in two or three dimensions, rigid rotors, wells and more. It also has links to a large collection of scientific applets.

C & C++ Code

  • Numerov_Harmonic_Oscillator.c
    This is a C program based on an algorithm in Quantum Chemistry, 6th Edition, Ira Levine, Pearson, p. 85. The program uses Numerov's Method to find a solution to the Schrodinger equation for the one-dimensional harmonic oscillator. This problem has an exact solution, and so the Numerov method is not really necessary to solve it. The purpose of this program is to demonstrate how to use the method. Because it is exactly solvable, the results of the program can be validated easily against the analytical solution. This version requires the user to supply successive guesses of the energy eigenvalue. The first step in using it is to read the code, which contains instructions on how to compile it and how to run it. It has built in help, and runs only in command line mode (it does not have a GUI.)It outputs an array of values of the solution to the Schrodinger equation. In other words, if psi(x) is the solution, then the output of the program is a sequence of values, psi(0), psi(1), psi(2), ..., psi(N), one per line, where N is a user input, at points x(0), x(1), ..., x(N), also chosen by the user. This array can be copied into a spreadsheet and plotted.
    The program is easily modified to use a binary search to hone in on the eigenvalue. This version has been tested on Fedora 8 and on Windows XP. It should run on most any platform.



  • IT Hare
    Opinions on all the aspects of software development, from UI to scalability, reliability and security, for all kinds of systems (from large-scale systems to embedded ones), the reasoning behind those opinions, and many practical observations.