Need help in evaluating integral with quad
Afficher commentaires plus anciens
Hi,I need to numerically evaluate an integral,for different values of a parameter,and store these in a vector.The integral is:
f(theta)=integral of(exp(-2x)*sin(2xsin(theta/2))dx, x running from 0 to 2 I am trying to attempt this with quad using the anonymous function approach.I coded it thus,
theta=0.01:0.1:2*pi-0.01;
f=@(x,th)(exp(-0.5*x)*sin(x*2*sin((th)/2)));
for i=1:length(theta)
th=theta(i);
born(i)=quad(@(x)f(x,th),0,2);
end;
I cannot understand why I get the error
??? Error using ==> mtimes
Inner matrix dimensions must agree.
Error in ==> @(x,th)(exp(-0.5*x)*sin(x*2*sin((th)/2)))
Error in ==> @(x)f(x,th)
Error in ==> quad at 77
y = f(x, varargin{:});
Error in ==> born_integral at 8
born(i)=quad(@(x)f(x,th),0,2);
Is there a way to make it work with quad or a similiar function ? (I'll try numerical integration algorithms as a last resort) Thanks in advance.
1 commentaire
John D'Errico
le 10 Mar 2011
Quad IS a numerical integration algorithm!!!!!
Réponse acceptée
Plus de réponses (1)
Matt Fig
le 10 Mar 2011
Or, you can do it in one shot with QUADV:
th = 0.01:0.1:2*pi-0.01;
f = @(x)(exp(-0.5*x).*sin(x*2*sin((th)/2)));
born = quadv(f,0,2);
Catégories
En savoir plus sur MATLAB dans Centre d'aide et File Exchange
Produits
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!