What is the “pdentrp” function in the “pdepe” function?

I want to know the specific function and code of the “pdentrp ” function. I searched for “help” and some network resources, but there was no gain. Can anyone help me?

Answer 1

[Josh Meyer]

This is an internal, private helper function, so it does not have documentation beyond help text. You can access the file with the command

edit /MATLAB/toolbox/matlab/funfun/private/pdentrp.m

The help text for this function is:

%PDENTRP  Interpolation helper function for PDEPE.
%   [U,UX] = PDENTRP(M,XL,UL,XR,UR,XOUT) uses solution values UL at XL and UR at XR
%   for successive mesh points XL < XR to interpolate the solution values U and
%   the partial derivative with respect to x, UX, at arguments XOUT(i) with
%   XL <= XOUT(i) <= XR.  UL and UR are column vectors. Column i of the output
%   arrays U, UX correspond to XOUT(i).
%
%   See also PDEPE, PDEVAL, PDEODES.

[feynman feynman]

what's the finite difference scheme for the interpolation of UX?