Matlab Equation

Discussion in 'Programmer's Corner' started by Cerkit, Jan 13, 2010.

  1. Cerkit

    Thread Starter Senior Member

    Jan 4, 2009
    Hi. How is it possible to write an equation for example f=X^2 so that anywhere in my code I can get the value of f for a given X by typing


    for some X value?

  2. steveb

    Senior Member

    Jul 3, 2008
    Simply create a function and put it in an m-file with the same name as your function. For example, for your squaring function chose a name like "Xsquared" for your function and store the function in a file called Xsquared.m. The function code in this m-file would look as follows in this case.

    Code ( (Unknown Language)):
    2. [FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]function[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Courier New][SIZE=2][FONT=Courier New][SIZE=2] [output_value] = Xsquared(x)[/SIZE][/FONT]
    3. [SIZE=2][FONT=Courier New]output_value = x^2;[/FONT][/SIZE]
    4. [/SIZE][/FONT][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff][FONT=Courier New][SIZE=2][COLOR=#0000ff]end[/COLOR][/SIZE][/FONT]
    To call the function, simply do the following Y=Xsquared(2) and Y will be set equal to 4 (or the square of whatever value you plug in). Make sure the function file in in your working directory, or keep it in a directory that Matlab can access for functions.
    Last edited: Jan 13, 2010