allow BivariatePWLFunction to accept a matrix of values at breakpoint pairs

[chriscoey]

for univariate, you are allowed to pass in a vector of breakpoints and a vector of function values at those points. bivariate forces you to pass in a function, but it should allow the matrix of values analogously to univariate. note that some patterns will be unavailable (BestFit).

[AndreOlds]

I am facing the same issue.
Is there a quick manner to convert a matrix of 2D values into a function to enable using the methods implemented in this package?

Thanks

[joehuchette]

It's not trivial, but also should be doable in a one or two dozen LOC: given input x, compute which domain triangle x lies upon, then compute the value of the affine function that passes through the corresponding breakpoint values.

I'm in the middle of a rewrite of the package which will make this easy to do.