Z = SIMP(DX,Y,NPTS) -- This function performs an integration on a set of equally spaced points. If NPTS is odd, Simpson's 1/3 rule is employed, if NPTS is even and greater than 4, Simpson's rule is applied to the first NPTS-1 points and a parabolic correction is added. If NPTS equals 2, a simple trapezodial integration is done; if NPTS equals 4, a cubic if fitted and integrated. FCTR: SI DX - Spacing between points. Y - Array of values. NPTS - Number of points.