QUAD, and most of the other integration functions in MATLAB, is written to evaluate the integrand at more than one point at a time. So it is expects to pass a vector input and get a vector output. You can add this "vectorization" with a loop in your integrand:
function EU = toy(d1,M)
EU = zeros(size(d1));
for k = 1:numel(EU)
test = zeros(size(M,1),size(M,2));
for i=1:size(M,1)
for j=1:size(M,2)
test(i,j) = M(i,j) + d1(k);
end
end
EU(k) = sum(sum(test));
end
Another way to add the outer loop (without modifying the integrand) is to use ARRAYFUN. Finally, QUAD is obsolete. We now recommend INTEGRAL. INTEGRAL expects the same kind of vectorization, but it also has the 'ArrayValued' option. If you set 'ArrayValued' to true, it will assume your function is vector-valued (doesn't matter if the vector only has one element!), so it will only call the integrand with scalar inputs. -- Mike
