Here is my request that Calculate allow direct function access without requiring me to convert my numbers to strings and build a string formula, only to have Calculate spend the time to parse it back to what I could have given it directly.
i.e. Something like: Calculate.Function.Average(double args), and also overloaded for variable number of arguments.
Your request is noted.
Using a single string as an argument does simplify the code. You do not have to have delegates for any number of possible argument combinations. It puts the burden of understanding/interpreting the argument on the functions itself. This makes extending the library quite simple.
Of course, this comes at the price you mentioned. We will discuss extending our single delegate model to handle a few common cases like a double argument.