C CSPS 10
C ..................................................................CSPS 20
C CSPS 30
C SUBROUTINE CSPS CSPS 40
C CSPS 50
C PURPOSE CSPS 60
C COMPUTES THE VALUE OF AN N-TERM EXPANSION IN SHIFTED CSPS 70
C CHEBYSHEV POLYNOMIALS WITH COEFFICIENT VECTOR C CSPS 80
C FOR ARGUMENT VALUE X. CSPS 90
C CSPS 100
C USAGE CSPS 110
C CALL CSPS(Y,X,C,N) CSPS 120
C CSPS 130
C DESCRIPTION OF PARAMETERS CSPS 140
C Y - RESULT VALUE CSPS 150
C X - ARGUMENT VALUE CSPS 160
C C - COEFFICIENT VECTOR OF GIVEN EXPANSION CSPS 170
C COEFFICIENTS ARE ORDERED FROM LOW TO HIGH CSPS 180
C N - DIMENSION OF COEFFICIENT VECTOR C CSPS 190
C CSPS 200
C REMARKS CSPS 210
C OPERATION IS BYPASSED IN CASE N LESS THAN 1 CSPS 220
C CSPS 230
C SUBROUTINES AND FUNCTION SUBPROGRAMS REQUIRED CSPS 240
C NONE CSPS 250
C CSPS 260
C METHOD CSPS 270
C DEFINITION CSPS 280
C Y=SUM(C(I)*TS(I-1,X), SUMMED OVER I FROM 1 TO N). CSPS 290
C EVALUATION IS DONE BY MEANS OF BACKWARD RECURSION CSPS 300
C USING THE RECURRENCE EQUATION FOR SHIFTED CSPS 310
C CHEBYSHEV POLYNOMIALS CSPS 320
C TS(N+1,X)=(4*X-2)*TS(N,X)-TS(N-1,X). CSPS 330
C CSPS 340
C ..................................................................CSPS 350
C CSPS 360
SUBROUTINE CSPS(Y,X,C,N) CSPS 370
C CSPS 380
DIMENSION C(1) CSPS 390
C CSPS 400
C TEST OF DIMENSION CSPS 410
IF(N)1,1,2 CSPS 420
1 RETURN CSPS 430
C CSPS 440
2 IF(N-2)3,4,4 CSPS 450
3 Y=C(1) CSPS 460
RETURN CSPS 470
C CSPS 480
C INITIALIZATION CSPS 490
4 ARG=X+X-1. CSPS 500
ARG=ARG+ARG CSPS 510
H1=0. CSPS 520
H0=0. CSPS 530
C CSPS 540
DO 5 I=1,N CSPS 550
K=N-I CSPS 560
H2=H1 CSPS 570
H1=H0 CSPS 580
5 H0=ARG*H1-H2+C(K+1) CSPS 590
Y=0.5*(C(1)-H2+H0) CSPS 600
RETURN CSPS 610
END CSPS 620