Why Does math.matrixFromFunction Return A Vanilla Array/Matrix?

[fweth]

I just wonder, looking at the documentation, math.matrixFromFunction should return an Array, so a Math.js object like math.zeros, but it returns a vanilla JS array. For my own usecases, I prefer vanilla JS arrays, so I'm happy with that! I just wonder where the difference comes from...

[josdejong]

In general, the idea is: Array in -> Array out, Matrix in -> Matrix out.

math.matrixFromFunction([3,3], i => i[0] - i[1])              // Array 
math.matrixFromFunction(math.matrix([3,3]), i => i[0] - i[1]) // Matrix