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Pade' Approximant

version 1.0.0.0 (1.57 KB) by Greg von Winckel
Computes coefficients of Pade' Approximants to symbolic functions.

3 Downloads

Updated 20 Jan 2004

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This script will compute the coefficients for the "symmetric" Pade' approximant to a symbolic function expanded at x=0. It also returns poles and zeros to ensure that the expansion does not have undesireable behavior in the region of interest. Users may modify and redistribute this script freely.

Comments and Ratings (6)

Wei Zhao

would be better if it could expand in any point

Johannes

Is it fixable to meet atan(x) ?
And will it hold for all real values in the rage of [-inf +inf]?
I have code in the hand that could also compute unsymmetric pade approximants but I only use it for exp(x). I yet did not have the time to try implementing it for symbolic functions. The expantion point can be defined on input already. I am interested on getting approximants for the arcustangens(x) Function that hold for all real values.

Michael Ktistakis

The code fails in cases the highest order coeffs are zero. (example: f=acos(x))

fser=taylor(f,0,Nc);
% Extract the expansion coefficients
c=sym2poly(fser)';
% Check that c includes the
% high order zero coeffs
if length(c) < Nc
c = [zeros(Nc-length(c),1);c];
end
% Reverse the order (ascending powers)
c=c(Nc:-1:1);

Taekjung Kim

Jörg Kubitz

a usefull thing
the documentation about y is wrong tho

Ymonnet Frederic

I search all data on pade approximant for a personnel work in french universitie

MATLAB Release Compatibility
Created with R12
Compatible with any release
Platform Compatibility
Windows macOS Linux

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