Quote Originally Posted by VBAhack View Post
Aeroengie,

You need to include both x & y in the matrix of p's. It will be two columns. Should work.
Hi. Thanks for replying. But, if the P matrices are two columns, then the final answer will be a 1 X 2, that is, one row two columns

( 1x4 * 4X4 * 4X2 ), where 1X4 is the matrix of the interpolant (cubed, squared, raised to one and constant), 4X4 is the 'M' matrix and the 4X2 is the matrix you are proposong).

Thus, if I have a 1 X 2, this doesn not sound right since the answer I seek is a single value (the value of y, given an x).

Holla.