create a function

• functions can be computed by attaching an orignin to an ensemble
• draggin does not work for this (possible bug)
• set the number of output dimensions
• set the function
• default is constant function
• this would behave like a neural approximation of what an input does
• user defined
• define a function using all or some of the input dimensions
• use x0, x1, x2, etc to refer to the dimensions
• input dimensions should be set to the number of dimensions of the ensemble, this is the default, don't change it