User defined functions

If you have a complex calculation that you reuse frequently, you don't have to
repeatedly enter a long, complex formula. Instead, you can create your own
function to perform the calculation. User-defined functions can be called just
like built-in ones, but it is up to you to define them. Next example shows how
to define function that calculate the volume of the cone :

Volume of Cone = (1/3) × PI × r² × h

This formula can be transformed in user defined function and entered in
CalcSharp in following steps :

Step 1. Formula above can be written as a function with two parameters :

cone_volume( radius, height ) = 1/3 * PI * radius ** 2 * height

Step 2. In order to define this function in CalcSharp, it is necessery to
replace parameter names with ordinal positions prefixed with '@' sign :

cone_volume( @1, @2 ) = 1/3 * PI * @1 **2 * @2

Step 3. To add this function in CalcSharp, right-click any function group in
expression builder and choose "Add function" from context menu. Fill
the form in following way :