DAY26
Wednesday, 11 July 2012

Today we might talk about:

• A function can call another function: program use_month_length calls function month_length() which calls leap_year().
• A function can call another function whose actual name is an input quantity: euler() can call a function whose "local" name is f(x), but whose actual name is specified by the user.
• Global variables; we've already seen automatic variables ("local, temporary") versus static variables ("local, but sticks around").

Programs and functions we might talk about:

• euler.c, a program which shows how we can write an ODE solver which will accept the name of the right hand side function as just another input quantity.
• leap_year.c, a bool function which determines (TRUE/FALSE) if a given year is a leap year.
• month_length.c, a function which returns the number of days in a month; this function calls leap_year();
• p8.14.c, a program which converts a number to a base between 2 and 16. The program is interesting because it uses three functions, and stores variables in global memory so that the functions can easily share data.
• plotter.c, a program which makes a table of a function using n equally spaced points from a to b. Right now, the function MUST be called "f(x)". We'd like to make it possible for the function to be a "variable", that is, just another input to the program.
• use_month_length.c, a program which calls month_length(), which calls leap_year();