5 * Revision 1.1.1.1 1996/04/01 15:02:27 mclareni
10 SUBROUTINE SPLAS2(N,NC,NCX,NCY,NX,NY,MX,MY,KX,KY,NDIMC,NDIMZ,
11 + XI,YI,ZI,KNOT,TX,TY,A,S,VT,W1,W2,LW,C,NERR)
13 #include "gen/imp64.inc"
14 DIMENSION XI(*),YI(*),ZI(NDIMZ,*),TX(*),TY(*)
15 DIMENSION A(N,*),S(*),VT(NC,*),W1(*),W2(*),C(NDIMC,*)
17 ************************************************************************
18 * NORBAS, VERSION: 15.03.1993
19 ************************************************************************
21 * THE SUBROUTINE SPLAS2 IS USED BY DSPAP2 FOR COMPUTING THE
23 * C(I,J) (I=1,...,NCX , J=1,...,NCY)
24 * OF A TWO-DIMENSIONAL POLYNOMIAL APPROXIMATION SPLINE Z = S(X,Y) IN
25 * REPRESENTATION OF NORMALIZED TWO-DIMENSIONAL B-SPLINES B(I,J)(X,Y).
27 ************************************************************************
29 PARAMETER (Z0 = 0 , Z1 = 1 , Z2 = 2 , Z10 = 10 , HALF = Z1/Z2)
31 * COMPUTE AN APPROXIMATION EPS0 TO THE RELATIVE MACHINE PRECISION
35 IF(Z1+EPS0 .NE. Z1) GO TO 10
38 * COMPUTE KNOTS BY MEANS OF GIVEN DATA POINTS (IF KNOT = 1 OR 2)
41 CALL DSPKN2(KX,KY,MX,MY,XI(1),XI(NX),YI(1),YI(NY),TX,TY,NERR)
42 ELSEIF(KNOT .EQ. 2) THEN
47 30 TX(I)=HALF*(XI(NX*(I-KX-2)/NCX+1)+XI(NX*I/NCX))
52 50 TY(J)=HALF*(YI(NY*(J-KY-2)/NCY+1)+YI(NY*J/NCY))
55 * COMPUTE MATRIX A AND SOLVE LINEAR LEAST SQUARES PROBLEM USING SVD
63 A((I-1)*NY+J,(IC-1)*NCY+JC)=
64 + DSPNB2(KX,KY,MX,MY,IC,JC,0,0,X,Y,TX,TY,NERR)
66 CALL DGESVD('O','A',N,NC,A,N,S,W1,1,VT,NC,W2,LW,INFO)
69 70 W1((I-1)*NY+J)=ZI(I,J)
70 CALL DMMPY(NC,N,A(1,1),A(2,1),A(1,2),W1(1),W1(2),W2(1),W2(2))
72 IF(S(J) .GT. EPS0*S(1)) THEN
78 CALL DMMPY(NC,NC,VT(1,1),VT(2,1),VT(1,2),W1(1),W1(2),W2(1),W2(2))
81 90 C(I,J)=W2((I-1)*NCY+J)