In general when A is dependend on B then A is component and B is argument
Some examples of different functions and how they map to DelftShell.Functions.
A function with one argument (year) and one component (dija)
A function with one argument (portofolio weight) 3 components (most-,least- and medium risk aversion). Or you could
model this as three separate functions with one argument and one component each.
Functions above are all 1D since they all have one argument.
2D functions: 
F(x,y) is dependend of x and y. Two arguments (x and y) and one component f(x,y)
A function with two arguments (horizontal and vertical position) and three components (R,G,B)