*DECK CPEVL
SUBROUTINE CPEVL (N, M, A, Z, C, B, KBD)
C***BEGIN PROLOGUE CPEVL
C***SUBSIDIARY
C***PURPOSE Subsidiary to CPZERO
C***LIBRARY SLATEC
C***TYPE SINGLE PRECISION (CPEVL-S)
C***AUTHOR (UNKNOWN)
C***DESCRIPTION
C
C Evaluate a complex polynomial and its derivatives.
C Optionally compute error bounds for these values.
C
C INPUT...
C N = Degree of the polynomial
C M = Number of derivatives to be calculated,
C M=0 evaluates only the function
C M=1 evaluates the function and first derivative, etc.
C if M .GT. N+1 function and all N derivatives will be
C calculated.
C A = Complex vector containing the N+1 coefficients of polynomial
C A(I)= coefficient of Z**(N+1-I)
C Z = Complex point at which the evaluation is to take place.
C C = Array of 2(M+1) words into which values are placed.
C B = Array of 2(M+1) words only needed if bounds are to be
C calculated. It is not used otherwise.
C KBD = A logical variable, e.g. .TRUE. or .FALSE. which is
C to be set .TRUE. if bounds are to be computed.
C
C OUTPUT...
C C = C(I+1) contains the complex value of the I-th
C derivative at Z, I=0,...,M
C B = B(I) contains the bounds on the real and imaginary parts
C of C(I) if they were requested.
C
C***SEE ALSO CPZERO
C***ROUTINES CALLED I1MACH
C***REVISION HISTORY (YYMMDD)
C 810223 DATE WRITTEN
C 890531 Changed all specific intrinsics to generic. (WRB)
C 890831 Modified array declarations. (WRB)
C 891214 Prologue converted to Version 4.0 format. (BAB)
C 900402 Added TYPE section. (WRB)
C***END PROLOGUE CPEVL
C
COMPLEX A(*),C(*),Z,CI,CIM1,B(*),BI,BIM1,T,ZA,Q
LOGICAL KBD
SAVE D1
DATA D1 /0.0/
ZA(Q)=CMPLX(ABS(REAL(Q)),ABS(AIMAG(Q)))
C***FIRST EXECUTABLE STATEMENT CPEVL
IF (D1 .EQ. 0.0) D1 = REAL(I1MACH(10))**(1-I1MACH(11))
NP1=N+1
DO 1 J=1,NP1
CI=0.0
CIM1=A(J)
BI=0.0
BIM1=0.0
MINI=MIN(M+1,N+2-J)
DO 1 I=1,MINI
IF(J .NE. 1) CI=C(I)
IF(I .NE. 1) CIM1=C(I-1)
C(I)=CIM1+Z*CI
IF(.NOT. KBD) GO TO 1
IF(J .NE. 1) BI=B(I)
IF(I .NE. 1) BIM1=B(I-1)
T=BI+(3.*D1+4.*D1*D1)*ZA(CI)
R=REAL(ZA(Z)*CMPLX(REAL(T),-AIMAG(T)))
S=AIMAG(ZA(Z)*T)
B(I)=(1.+8.*D1)*(BIM1+D1*ZA(CIM1)+CMPLX(R,S))
IF(J .EQ. 1) B(I)=0.0
1 CONTINUE
RETURN
END