5 * Revision 1.1.1.1 1996/04/01 15:02:26 mclareni
10 SUBROUTINE SPLAS1(N,NC,M,K,XI,YI,KNOT,T,A,S,VT,W,LW,C,NERR)
12 #include "gen/imp64.inc"
13 DIMENSION XI(*),YI(*),T(*),A(N,*),S(*),VT(NC,*),W(*),C(*)
15 ************************************************************************
16 * NORBAS, VERSION: 15.03.1993
17 ************************************************************************
19 * THE SUBROUTINE SPLAS1 IS USED BY DSPAP1 FOR COMPUTING THE
20 * COEFFICIENTS C(1),...,C(NC) OF A POLYNOMIAL APPROXIMATION SPLINE
21 * S(X) IN B-SPLINE REPRESENTATION
23 ************************************************************************
25 PARAMETER (Z0 = 0 , Z1 = 1 , Z2 = 2 , Z10 = 10 , HALF = Z1/Z2)
27 * COMPUTE AN APPROXIMATION EPS0 TO THE RELATIVE MACHINE PRECISION
31 IF (Z1+EPS0 .NE. Z1) GO TO 10
34 * COMPUTE KNOTS BY MEANS OF GIVEN DATA POINTS (IF KNOT = 1 OR 2)
37 CALL DSPKN1(K,M,XI(1),XI(N),T,NERR)
38 ELSEIF (KNOT .EQ. 2) THEN
43 30 T(I)=HALF*(XI(N*(I-K-2)/NC+1)+XI(N*I/NC))
46 * COMPUTE MATRIX A AND SOLVE LINEAR LEAST SQUARES PROBLEM USING SVD
50 40 A(I,J)=DSPNB1(K,M,J,0,XI(I),T,NERR)
51 CALL DGESVD('O','A',N,NC,A,N,S,W,1,VT,NC,W,LW,INFO)
52 CALL DMMPY(NC,N,A(1,1),A(2,1),A(1,2),YI(1),YI(2),W(1),W(2))
54 IF (S(J) .GT. EPS0*S(1)) THEN
60 CALL DMMPY(NC,NC,VT(1,1),VT(2,1),VT(1,2),W(1),W(2),C(1),C(2))