Surface fitting and a new direct method for solving block band linear system

Empirical values loaded by accidental errors of normal law are given in the grid points of a rectangular domain. The most probable true values are determined by minimizing the sum of the rth divided differences and the differences between the empirical and the smoothed values simultaneously. Choosing appropriate weights the quality of smoothing can be controlled. The coefficients of the linear algebraic equation system (L.E.S.) to be solved can be arranged in a block band matrix. A new direct method for solving the L.E.S. is presented needing comparatively small storing capacity and number of operations. © 1999 Elsevier Science Ltd. All rights reserved.