I am unable to use numerical_integral (GSL C library) with a complex integrand. I haven't found anything about this issue in the documentation. Is this correct? nintegral works correctly.
e.g.
f(x) = (exp(i*x) + exp(-i*x))/2
f(x).nintegral(x,0,1)
numerical_integral(f,0,1)
the above code outputs
(0.8414709848078965, 9.34220461887732e-15, 21, 0)
Error in lines 3-3
...
TypeError: unable to coerce to a real number
Tested with SageMath version 7.5.1 and Cocalc.
Cordially
