Cleve Moler- Computing pi

Hi guys,

I tried the chud_pi function in Cleve Moler's Computing Pi webpage ( http://www.mathworks.com/company/newsletters/articles/clevescorner-computing-pi.html?s_v1=37969458_1-EEGYAZ). Function reproduced below:

function P = chud_pi(d)
% CHUD_PI Chudnovsky algorithm for pi.
% chud_pi(d) produces d decimal digits.

k = sym(0);
s = sym(0);
sig = sym(1);
n = ceil(d/14);
for j = 1:n
    s = s + sig * prod(3*k+1:6*k)/prod(1:k)^3 * ...
    (13591409+545140134*k) / 640320^(3*k+3/2);
    k = k+1;
    sig = -sig;
end
S = 1/(12*s);
P = vpa(S,d);

However, I got back the error messages:

??? Error using ==> maple
Error, (in linsolve) 1st argument fails to evaluate to a matrix

Error in ==> sym.mldivide at 28
   X = maple('linsolve',char(A),char(B),'''_rank''');

Error in ==> sym.mrdivide at 27
   X = (A.'\B.').';

Error in ==> chud_pi at 10
    s = s + sig * prod(3*k+1:6*k)/prod(1:k)^3 * ...

Any ideas?

Thanks!

-Rick

[per isakson]

Matlab release? Mathworks ceased using Maple a few years ago.

[John D'Errico]

It works fine for me, using the current release of MATLAB.

[bym]

errors on mine (R2008b using Mupad)

chud_pi(50)

??? Index exceeds matrix dimensions.

Error in ==> sym.mldivide at 45

X = fullshape(out(1));

Error in ==> sym.mrdivide at 34

X = (A.'\B.').';

Error in ==> chud_pi at 15

s = s + sig * prod(3*k+1:6*k)/prod(1:k)^3 * ...