C
C PAGE 141-142: NUMERICAL MATHEMATICS AND COMPUTING, CHENEY/KINCAID, 1985
C
C FILE: DERIV.FOR
C
C DERIVATIVE BY CENTER DIFFERENCES AND RICHARDSON EXTRAPOLATION (DERIV,F)
C
PARAMETER (ID=15)
DIMENSION D(ID,ID)
EXTERNAL F
DATA H/1.0/,N/10/
PI3=4.0*ATAN(1.0)/3.0
CALL DERIV(F,PI3,N,H,D,ID)
STOP
END
FUNCTION F(X)
F=SIN(X)
RETURN
END
SUBROUTINE DERIV(F,X,N,H,D,ID)
DIMENSION D(ID,N)
DO 3 I=1,N
D(I,1)=(F(X+H)-F(X-H))/(2.0*H)
Q=4.0
DO 2 J=1,I-1
D(I,J+1)=D(I,J)+(D(I,J)-D(I-1,J))/(Q-1.0)
Q=4.0*Q
2 CONTINUE
PRINT 4,(D(I,J),J=1,I)
H=H/2.0
3 CONTINUE
4 FORMAT(5X,5E22.14)
RETURN
END
.