Double Integration error using /

Hi,

I am trying to do double integration. But I am getting following error.

inte = @(y,x) (cos(x).^2)/(1 + alpha/(cos(x)*sqrt(1 - 1/y.^2))).^2*(1/y.^3 - 1/y.^5);

integral2(inte,1,Inf,0,pi/2)

Error: Error using /

Matrix dimensions must agree

Answer 1

[Chunru]

Keep in mind that the function should be defined for vector arguments x and y. Therefore some * and / should be changed to .* and ./.

alpha = 1;
inte = @(y,x)  (cos(x).^2)./(1 + alpha./(cos(x).*sqrt(1 - 1./y.^2))).^2 .*(1./y.^3 - 1./y.^5);
integral2(inte,1,Inf,0,pi/2)

ans = 0.0319

[Shanmakha Mangadahalli Siddaramu]

thanks :)

Answer 2

[Mike Croucher]

You need to vectorise your equation

alpha = 1.0;
inte = @(y,x)  (cos(x).^2)./(1 + alpha./(cos(x).*sqrt(1 - 1./y.^2))).^2.*(1./y.^3 - 1./y.^5);
integral2(inte,1,Inf,0,pi/2)

ans =
    0.0319

You didn't define alpha so I took a guess.

Hope this helps,

Mike

[Shanmakha Mangadahalli Siddaramu]

Thanks :)