### LON-CAPA Help

With variables, you can store strings or numbers. **Functions** allow
you to manipulate these strings or numbers. Functions work like mathematical
functions: They take some number of arguments in, and return one argument,
usually a number or a string for our purposes. There are a lot of functions
available in LON-CAPA. You can see a complete list in the Script section
and LON-CAPA function section .

For now, let's just look at some simple examples.

$a = -3.0;

$b = &sin($a);

$c = &pow(3.0, &abs($a));

Figure 1: Some Function Calls
In the **Script** block, function names start with **&**. Some
example function calls are shown above.
You can see that functions can take either variables, numbers, or the results
of other function calls as parameters. The `&sin` function returns
the sine of an angle expressed in radians. `&pow` raises the first
parameter to the power of the second parameter. `&abs` returns the
absolute value of the argument.