Statistics Function Implementation

minimum.pro

sum.pro

Overflow Problems

Corrected sum.pro

mean.pro

Integer Problems

Integer Problems

Corrected mean.pro

sum_squares.pro

variance.pro

sd.pro

Shell Programming

UNIX Tip of the Day

UNIX Tip of the Day

UNIX Tip of the Day

UNIX Tip of the Day

UNIX Tip of the Day

IMPORTANT UNIX Concepts

Other IMPORTANT UNIX Concepts

% Environment Variables %

Shell Variables

Environment vs. Shell Variables

Environment vs. Shell Variables

Environment vs. Shell Variables

Environment vs. Shell Variables

Environment & Shell Variables

Useful Shell Variables

What is shell programming?

.login file

.cshrc file

When these files are executed?

Other useful .login and .cshrc entries

User defined shell program

A simple shell program

We would rather see...

Special Shell Variables Set

Another Special
Shell Variables

shell program
swap_bytes

Making swap_bytes
shell script executable

To run swap_bytes

Limitation of swap_bytes

Improvement to swap_bytes

Commad exit status

Informational message from swap_bytes

Interactive swap_bytes

Interactive swap_bytes

Interactive swap_bytes example

UNIX Quotes

A note about quotes in UNIX

A note about shell variables

A more complex shell program

pgmtoraw shell script design

Define input and output files pgmtoraw

Dimensions of input image
( pnmfile)

pgmtoraw (continued)

pgmtoraw (continued)

Resulting pgmtoraw utility

Current Limitations of Resulting pgmtoraw utility

Shell Scripts Wrappers
and IDL

pnmtojpeg.pro

Usage of pnmtojpeg.pro in IDL

Usage of pnmtojpeg.pro in IDL

IDL_PATH
environment variable

pnmtojpeg.csh

Usage of pnmtojpeg.csh

Limitation of pnmtojpeg.csh

Usage cases of pnmtojpeg
(no command line arguments)

Usage cases of pnmtojpeg
(1 command line argument)

Usage cases of pnmtojpeg
(2 command line arguments)

Yet another wrapper
 pnmtojpeg

Code for no argument case

Code for 1 argument case

Code for 2 argument case

pnmtojpeg summary

Summary

Other Shell Constructs
to keep in mind