DP1VLU(3)

SYNOPSIS
SUBROUTINE DP1VLU (L, NDER, X, YFIT, YP, A)

NAME
dp1vlu - Use the coefficients generated by DPOLFT to evaluate the polynomial fit of degree L, along with the first NDER of its derivatives, at a specified point.

LIBRARY
SLATEC

CATEGORY
K6

TYPE
DOUBLE PRECISION (PVALUE-S, DP1VLU-D)

KEYWORDS
CURVE FITTING, LEAST SQUARES, POLYNOMIAL APPROXIMATION

AUTHOR
Shampine, L. F., (SNLA) Davenport, S. M., (SNLA)

DESCRIPTION
Abstract The subroutine DP1VLU uses the coefficients generated by DPOLFT to evaluate the polynomial fit of degree L , along with the first NDER of its derivatives, at a specified point. Computationally stable recurrence relations are used to perform this task. The parameters for DP1VLU are Input -- ALL TYPE REAL variables are DOUBLE PRECISION L - the degree of polynomial to be evaluated. L may be any non-negative integer which is less than or equal to NDEG , the highest degree polynomial provided by DPOLFT . NDER - the number of derivatives to be evaluated. NDER may be 0 or any positive value. If NDER is less than 0, it will be treated as 0. X - the argument at which the polynomial and its derivatives are to be evaluated. A - work and output array containing values from last call to DPOLFT . Output -- ALL TYPE REAL variables are DOUBLE PRECISION YFIT - value of the fitting polynomial of degree L at X YP - array containing the first through NDER derivatives of the polynomial of degree L . YP must be dimensioned at least NDER in the calling program.

REFERENCES
L. F. Shampine, S. M. Davenport and R. E. Huddleston, Curve fitting by polynomials in one variable, Report SLA-74-0270, Sandia Laboratories, June 1974.

ROUTINES CALLED
XERMSG

REVISION HISTORY (YYMMDD)
740601 DATE WRITTEN
890531 Changed all specific intrinsics to generic. (WRB)
890911 Removed unnecessary intrinsics. (WRB)
891006 Cosmetic changes to prologue. (WRB)
891006 REVISION DATE from Version 3.2
891214 Prologue converted to Version 4.0 format. (BAB)
900315 CALLs to XERROR changed to CALLs to XERMSG. (THJ)
900510 Convert XERRWV calls to XERMSG calls. (RWC)
920501 Reformatted the REFERENCES section. (WRB)