Comments and Ratings

Hi all

I am using the function in Matlab R2008a
I entered the command besselzero(1/2,1,2)
and the result is different than the value from
Mathematica s BesselYZero[1/2,1]
I also tried some other combinations which seemed fine.
I just wonder if this is a special case or I should check
the numbers given by this Matlab function with some other online sources. Thanks

example needed

Good luck

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.

I want to know some simple methods of solving integration

Very simple and straight forward. Great program and time saver

why doesn't this work for derivatives, when I use the standard iterative scheme to get the modes of the differentiated function?

good job I just need them thx

very accurate, easily implemented. thank you

Does not integrate correctly

Works pretty well - thanx

For production use, this function is superseded by x=A\b in MATLAB, which now includes a test for banded matrices (and uses LAPACK). I compared it in MATLAB 7.5 with A=spdiags(rand(n,5),-2:2,n,n); A=A+A'+10*speye(n) which is symmetric and positive definite. This pentsolve function was from 20x to 230x slower than x=A\b, as n increased from 100 to 10,000. The slowdown is linear; that is, this function seems to behave like O(n^2) time (which is surprising since the code doesn't have an O(n^2) behavior in it). The same thing occurs with unsymmetric banded matrices.

The accuracy of this function is fine. Its purpose now on the File Exchange is now no longer the need for speed; it's only for illustrating an algorithm (for which it's still useful).

Thus, if you're looking just to solve Ax=b for your pentadiagonal system, just use x=A\b. If you want to read the code to understand an algorithm, then this code is still useful.

I would like Tabulated Gauss points

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);

It works just fine

j'ai male a trouver la solution de l'equation dde la gaine fini et infini de la fibre vouler vous m'aider svp.

Nice work. You've saved me a lot of time.

works great