I have x, y, and z data sets. for example, x, y and z data are 1000 from one measurment. From five measurment, I have 5000 data points for each x, y and z. By using these points, I create the 3d surface. We know new x1 and y1, but dont know z1. to predict the z1 according to 3d surface, we use interpolation. this interpolation is thin-plate spline interpolation. I need help this mathematic concept to change Matlab code.