Double Integral Fail Error. Numerical Integration Fails.

Hi All,

I am trying to solve an equation with double integral but it is giving me error as 'The integration was unsuccessful' , Infinite or Not-a-Number value encountered. However, when i use Mathematica for the same equation, it is giving me answer. My question is, isn't Matlab also supposed to give the answer same as Mathematica?

Here is the equation I am trying to solve and the Matlab code. Could you check where i am doing it wrong?

eta = 0.9;   
psplit = 0.3; 
PsN0dB = 0:5:45;
PsN0 = 10.^(PsN0dB/10);
v1 = 1;
v2 = 0.0625;
v3 = 0.0625;
v4 = 1;
a1 = 0.2; 
a2 = 0.8; 
for p = 1: length(PsN0)
lim1 = a2 ./ a1;
M_2 = @(m,n)((m .* n) ./ ((1 + n) .* ((1 - psplit) .* PsN0(p) .* (a2 - (n .* a1))).^2)) ...
    .* exp(-(v2 - ((v1 .* v3) ./ (v4 .* n))) .* (n ./ ((1 - psplit) .* PsN0(p) .* ...
    (a2 - (n .* a1)))) .* ( m - ((v4 .* (1 - psplit) .* PsN0(p) .* ...
    (a2 - (n .* a1))) ./ (eta .* psplit .* PsN0(p) .* m)))) .* ...
    expint((v1 .* ((n .* v4) + (m .* v3))) ./ (v4 .* (1 - psplit) .* PsN0(p) .* (a2 - (n .* a1)))); 

G(p)= (1 ./ (2 .* log(2))) .* ((v3 .* v2 .* v1)./ v4) .* integral2(M_2,0,lim1,1,Inf);
end

[Ameer Hamza]

What is the correct value of integral? As it is currently written, it is not a simple 2D integral. The 'm' term outside the inner integral will not be integrated, and the final solution will be a function of 'm', not a constant.

[Glorit P.]

Hi Ameer,

Thank you for your reply. The m term can be inside the inner integral. But still i am not able to get the answer. However, Mathematica is able to give answer for the same equation. Do you know what could be possible wrong here? Could you check?

BR,

Glorit P.

[Ameer Hamza]

Can you show the solution given by Mathematica?