Module DBS3DR in IMSLMEvaluate the derivative of a three-dimensional tensor-product spline, given its tensor-product B-spline representation.
R = DBS3DR(IXDER, IYDER, IZDER, X, Y, Z, KXORD, KYORD, KZORD, XKNOT, YKNOT, ZKNOT, NXCOEF, NYCOEF, NZCOEF, BSCOEF)| E3a2 | Evaluation of derivatives of fitted functions |