The function may be called by the names: d02uzc or nag_ode_bvp_ps_lin_cheb_eval.
d02uzc returns the value, , of the th Chebyshev polynomial evaluated at a point ; that is, .
Trefethen L N (2000) Spectral Methods in MATLAB SIAM
1: – IntegerInput
On entry: the order of the Chebyshev polynomial.
2: – doubleInput
On entry: the point at which to evaluate the polynomial.
3: – double *Output
On exit: the value, , of the Chebyshev polynomial order evaluated at .
4: – NagError *Input/Output
The NAG error argument (see Section 7 in the Introduction to the NAG Library CL Interface).
6Error Indicators and Warnings
Dynamic memory allocation failed.
See Section 3.1.2 in the Introduction to the NAG Library CL Interface for further information.
On entry, argument had an illegal value.
On entry, .
An internal error has occurred in this function. Check the function call and any array sizes. If the call is correct then please contact NAG for assistance.
See Section 7.5 in the Introduction to the NAG Library CL Interface for further information.
Your licence key may have expired or may not have been installed correctly.
See Section 8 in the Introduction to the NAG Library CL Interface for further information.
On entry, .
The accuracy should be close to machine precision.
8Parallelism and Performance
d02uzc is not threaded in any implementation.
A set of Chebyshev coefficients is obtained for the function defined on using d02ucc. At each of a set of new grid points in the domain of the function d02uzc is used to evaluate each Chebshev polynomial in the series representation. The values obtained are multiplied to the Chebyshev coefficients and summed to obtain approximations to the given function at the new grid points.