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Chebfun V4

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Chebfun V4

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30 Apr 2009 (Updated )

Numerical computation with functions instead of numbers.

Editor's Notes:

This file was selected as MATLAB Central Pick of the Week

diffexp
function pass = diffexp
% Tests the computation of derivatives using DIFF  
% when the chebfuns are defined on unbounded domains.

tol = chebfunpref('eps');

f = chebfun(@(x) exp(x), [-inf,2]);
pass(1) = norm(f-diff(f),inf) < tol*5000;
pass(2) = norm(f-diff(f,2),inf) < max(1e-10, tol*1000);

f = chebfun(@(x) exp(-x.^2), [-inf,inf]);
df = chebfun(@(x) -2*x.*exp(-x.^2), [-inf,inf]);
pass(3) = norm(df-diff(f),inf) < tol*100;

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