User defined function

A user defined function is a functioned defined by an algebraic expression. Support for this feature is courtesy of the wonderful exprtk library developed by Arash Partow.

A user defined function has a name, parameters and an expression. Example expressions are things like x+y or sin(x). More details of the sorts of expressions possible can be found in the User Defined Functions section of the manual.

The parameters are specified as part of the name, so a user defined function adding x and y would be called useradd(a,y) and the sin example might be called mysin(x). Functions with up to two arguments can be wired on the canvas. User defined functions can call other user defined functions, so specifying more than 2 parameters can be a useful thing to do.