d02uwc interpolates from a set of function values on a supplied grid onto a set of values for a uniform grid on the same range. The interpolation is performed using barycentric Lagrange interpolation. d02uwc is primarily a utility function to map a set of function values specified on a Chebyshev Gauss–Lobatto grid onto a uniform grid.
The function may be called by the names: d02uwc or nag_ode_bvp_ps_lin_grid_vals.
d02uwc interpolates from a set of function values, , on a supplied grid, , for , onto a set of values, , on a uniform grid, , for . The image has the same range as , so that , for . The interpolation is performed using barycentric Lagrange interpolation as described in Berrut and Trefethen (2004).
d02uwc is primarily a utility function to map a set of function values specified on a Chebyshev Gauss–Lobatto grid computed by d02ucc onto an evenly-spaced grid with the same range as the original grid.
Berrut J P and Trefethen L N (2004) Barycentric lagrange interpolation SIAM Rev.46(3) 501–517
1: – IntegerInput
On entry: , where the number of grid points for the input data is .
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.
d02uwc is intended, primarily, for use with Chebyshev Gauss–Lobatto input grids. For such input grids and for well-behaved functions (no discontinuities, peaks or cusps), the accuracy should be a small multiple of machine precision.
8Parallelism and Performance
Background information to multithreading can be found in the Multithreading documentation.
d02uwc is not threaded in any implementation.
This example interpolates the function , as specified on a -point Gauss–Lobatto grid on , onto a coarse uniform grid.