isMatrixArray = function isMatrixArray(x) {
            return x instanceof Array;
          }
Sets the x, y, and z component of the vector using two or three separate
variables, the data from a p5.Matrix, or the values from a float array.

@method set
@param {p5.Matrix|Float32Array|Number[]} [inMatrix] the input p5.Matrix or
                                    an Array of length 16
@chainable