CSEVL
This function evaluates the N‑term Chebyshev series.
Function Return Value
CSEVL — Function value. (Output)
Required Arguments
X — Argument at which the series is to be evaluated. (Input)
CS — Vector of length N containing the terms of a Chebyshev series. (Input)
In evaluating CS, only half of the first coefficient is summed.
Optional Arguments
N — Number of terms in the vector CS. (Input)
Default: N = size(CS, 1)
FORTRAN 90 Interface
Generic: CSEVL (X, CS [, …])
Specific: The specific interface names are S_CSEVL and D_CSEVL.
FORTRAN 77 Interface
Single: CSEVL (X, CS, N)
Double: The double precision function name is DCSEVL.
Description
Function CSEVL evaluates a Chebyshev series whose coefficients are stored in the array s of length n at the point x. The argument x must lie in the interval[–1, +1]. Other finite intervals can be linearly transformed to this canonical interval. Also, the number of terms in the series must be greater than zero but less than 1000. This latter limit is purely arbitrary; it is imposed in order to guard against the possibility of a floating point number being passed as an argument for n.
Comments
Informational error
Type | Code | Description |
|---|
3 | 7 | X is outside the interval (‑1.1, +1.1) |
