what that is mean n, into Shanks acceleration

what that is mean n, into Shanks acceleration

clc
clear all
S=@(x) (x(1:end-2).*x(3:end)-x(2:end-1).^2)...
  ./(x(3:end)-2*x(2:end-1)+x(1:end-2));
tic
*n=25*;
x=cumsum(-1./(1:2:2*n).*(-1).^(1:n));
x1=S(x);
x2=S(x1);
x3=S(x2)
4*[x(end);x1(end);x2(end);x3(end)]
toc

Please I need you're help please!!!

Answer 1

[Star Strider]

The value of ‘n’ is the limit of the length of the vector in the ‘x’ calculation.

[Star Strider]

The value is given there as 25. My impression from the Wikipedia article on Shanks transformation is that the choice of ‘n’ is arbitrary, and depends on the sequence.

In the example you cited, ‘x’ is the sequence. (It is likely the same sequence as in the Wikipedia article, and calculates the value of π.)