csevl.f
FUNCTION CSEVL (X, CS, N)
C***BEGIN PROLOGUE CSEVL
C***PURPOSE Evaluate a Chebyshev series.
C***LIBRARY SLATEC (FNLIB)
C***CATEGORY C3A2
C***TYPE SINGLE PRECISION (CSEVL-S, DCSEVL-D)
C***KEYWORDS CHEBYSHEV SERIES, FNLIB, SPECIAL FUNCTIONS
C***AUTHOR Fullerton, W., (LANL)
C***DESCRIPTION
C
C Evaluate the N-term Chebyshev series CS at X. Adapted from
C a method presented in the paper by Broucke referenced below.
C
C Input Arguments --
C X value at which the series is to be evaluated.
C CS array of N terms of a Chebyshev series. In evaluating
C CS, only half the first coefficient is summed.
C N number of terms in array CS.
C
C***REFERENCES R. Broucke, Ten subroutines for the manipulation of
C Chebyshev series, Algorithm 446, Communications of
C the A.C.M. 16, (1973) pp. 254-256.
C L. Fox and I. B. Parker, Chebyshev Polynomials in
C Numerical Analysis, Oxford University Press, 1968,
C page 56.
C***ROUTINES CALLED R1MACH, XERMSG
C***REVISION HISTORY (YYMMDD)
C 770401 DATE WRITTEN
C 890831 Modified array declarations. (WRB)
C 890831 REVISION DATE from Version 3.2
C 891214 Prologue converted to Version 4.0 format. (BAB)
C 900315 CALLs to XERROR changed to CALLs to XERMSG. (THJ)
C 900329 Prologued revised extensively and code rewritten to allow
C X to be slightly outside interval (-1,+1). (WRB)
C 920501 Reformatted the REFERENCES section. (WRB)
C***END PROLOGUE CSEVL