The x,y values form a relativly linear surface that twists in the z direction.
The data is taken from a valve calibration. The pressure is measured for each position of the valve. However there is a 3rd variable in the system. This means that the pressure required is dependent on valve position and the 3rd variable. This third variable causes small changes in the other two. What I am trying to do is calculate my valve position for a known pressure and 3rd variable. The data doesn't need to be smoothed.
