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Highlights from
Chebfun V4

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Chebfun V4



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

Chebyshev polynomials as plotted by Higham and Higham

Chebyshev polynomials as plotted by Higham and Higham

Nick Trefethen, 13th December 2011

(Chebfun example approx/ChebPolysHigham.m)

On p. 259 of their Matlab Guide, 2nd ed. [1], Higham and Higham present an attractive 3D plot of several Chebyshev polynomials. Here is their plot reproduced in Chebfun.

k = [0 2 4 10 20 40 60];
x = chebfun('x'); one = 1 + 0*x;
LW = 'linewidth'; FS = 'fontsize'; fs = 14;
for j = 1:length(k)
  plot3(j*one,x,chebpoly(k(j)),LW,1.6), hold on
box on
set(gca,'dataaspectratio',[1 0.75 4]), view(-72,28)
xlabel('k',FS,fs), ylabel('x',FS,fs), set(gca,FS,fs)
h = get(gca,'xlabel'); set(h,'position',get(h,'position')+[1.5 0.1 0])
h = get(gca,'ylabel'); set(h,'position',get(h,'position')+[0 0.25 0])


[1] D. J. Higham and N. J. Higham, Matlab Guide, 2nd ed., SIAM, 2005.

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