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 specifiying more than 2 parameters can be a
useful thing to do.