End of file
Contents
Index
SUBROUTINE PSPVAL (TV,N,T,AX,BX,CX,DX,AY,BY,CY,DY,SX,SY)
C
C*****************************************************************
C *
C This SUBROUTINE evaluates a parametric cubic spline *
C given by its component functions SX(T), SY(T) in the form: *
C *
C SX := SX(T) = AX(I) + BX(I)(T-T(I)) + CX(I)(T-T(I))**2 + *
C + DX(I)(T-T(I))**3 *
C *
C SY := SY(T) = AY(I) + BY(I)(T-T(I)) + CY(I)(T-T(I))**2 + *
C + DY(I)(T-T(I))**3 *
C *
C for T in the interval [T(I),T(I+1)], I=0,1,...,N-1. *
C *
C The program computes the values of SX(T) and SY(T) at T=TV. *
C *
C *
C INPUT PARAMETERS: *
C ================= *
C TV : value where the component functions SX(T) and SY(T) *
C are to be evaluated *
C N : index of the last node *
C T : vector T(0:N); the nodes T(I), I=0,1,...,N *
C AX : ] N+1-vectors ..(0:N); *
C BX : ] their elements 0, ..., N-1 describe the component *
C CX : ] function SX(T). *
C DX : ] *
C *
C AY : ] N+1-vectors ..(0:N); *
C BY : ] their elements 0, ..., N-1 describe the component *
C CY : ] function SY(T). *
C DY : ] *
C The elements BX(N), CX(N), DX(N), BY(N), CY(N) and *
C DY(N) are used for auxiliary purposes. *
C *
C *
C OUTPUT PARAMETERS: *
C ================== *
C SX : Functional value for SX(T) at T=TV *
C SY : Functional value for SY(T) at T=TV *
C *
C----------------------------------------------------------------*
C *
C Subroutines required: SPVAL *
C *
C*****************************************************************
C *
C Author : Günter Palm *
C Date : 06.01.1991 *
C Source : FORTRAN 77 *
C *
C*****************************************************************
C
C-----Declarations
C
IMPLICIT DOUBLE PRECISION (A-H, O-Z)
DOUBLE PRECISION T(0:N), AX(0:N), BX(0:N), CX(0:N), DX(0:N),
+ AY(0:N), BY(0:N), CY(0:N), DY(0:N)
C
C-----Compute the functional values of the component splines
C SX(T) and SY(T)
C
SX = SPVAL (TV,N,T,AX,BX,CX,DX)
SY = SPVAL (TV,N,T,AY,BY,CY,DY)
C
RETURN
END
Begin of file
Contents
Index