Question

trying to use the following code to evaluate a triple integral which is a function of q,u. getting the error,

Warning: Maximum function count exceeded; singularity likely. 
In quad at 107
In test1>Inner at 12
In test1>@(x)Inner(x) at 5
In quad at 76
In test1 at 5

Does anyone know what’s wrong with this code?

function [r] = test1(q,u)
b = u;
r = zeros(1);
for i = 1 : length(q);
    r(i) = quad(@(x)Inner(x),-2,q);
end;


function [w] = Inner(k)
w = zeros(1);
for i = 1 : length(k);
    w(i) = quad(@(n)InnerIntegral(n).*unifpdf(k(i)-n,-1,1),0,k(i)-1,k(i)+1);
end;



function [y] = InnerIntegral(n)
y = zeros(1);
for i = 1 : length(n);
    y(i) = quad(@(m)unifpdf(n(i)-m, -b, b).*unifpdf(m,-b,b), n(i)-b,n(i)+b);
end;
end
end
end

Answer 1

When you define multiple functions like this, each function’s end statement must precede the next call to function. Currently, it looks like this is one giant function with a subfunction called Inner and that subfunction has yet another subfunction called InnerIntegral. So test1 is trying to call Inner, but `Inner‘s definition doesn’t occur until later inside of the definition of test1.