1. Functions (subprograms)
Built-in functions (sin, cos, ln, etc.)
User-defined functions
Sin (3.14)
(argument)
Function name

2. User-defined functions
Created as a .m file
1st line is function definition line function [output variables] = function_name(input variables)
function_name same as filename
Function is called from main script by [output variables] = function_name(input variables)

3. Local vs Global Variables
Local variables
Only recognized within function file
Can reuse the same variable names in another function file
Global variables
Name (and values) recognized globally (in all files involved)
Need to be declared as global in all files involved global a x q

4. Data files Data from lab instrumentation
Saved in ASCII as pv_data.m (any extension except .mat)
Data as numbers in columns and rows separated by space
Using your favorite text editor
Change any other delimiters (comma, colon) to space
Remove any headers
Load into Matlab by load pv_data.m
Data is now available as variable(array) pv_data

5. Exporting data files Exporting an array A in Matlab session
>>save my_results.txt A -ASCII
To use other delimiters
>>dlmwrite('my_results.txt',A,';' )
Default delimiter comma
Space as delimiter by ' '
No delimiter by ''