File: PDER.FT of Tape: Various/ETH/eth11-1
(Source file text)
C .................................................................. C C SUBROUTINE PDER C C PURPOSE C FIND DERIVATIVE OF A POLYNOMIAL C C USAGE C CALL PDER(Y,IDIMY,X,IDIMX) C C DESCRIPTION OF PARAMETERS C Y - VECTOR OF COEFFICIENTS FOR DERIVATIVE, ORDERED FROM C SMALLEST TO LARGEST POWER C IDIMY - DIMENSION OF Y (EQUAL TO IDIMX-1) C X - VECTOR OF COEFFICIENTS FOR ORIGINAL POLYNOMIAL, C ORDERED FROM SMALLEST TO LARGEST POWER C IDIMX - DIMENSION OF X C C REMARKS C NONE C C SUBROUTINES AND FUNCTION SUBPROGRAMS REQUIRED C NONE C C METHOD C DIMENSION OF Y IS SET AT DIMENSION OF X LESS ONE. DERIVATIVE C IS THEN CALCULATED BY MULTIPLYING COEFFICIENTS BY THEIR C RESPECTIVE EXPONENTS. C C .................................................................. C SUBROUTINE PDER(Y,IDIMY,X,IDIMX) DIMENSION X(1),Y(1) C C TEST OF DIMENSION IF (IDIMX-1) 3,3,1 1 IDIMY=IDIMX-1 EXPT=0. DO 2 I=1,IDIMY EXPT=EXPT+1. 2 Y(I)=X(I+1)*EXPT GO TO 4 3 IDIMY=0 4 RETURN END C