>>>>> "Edwin" == Edwin Woollett <woollett at charter.net> writes:
Edwin> I am assuming quad_qags will return a noun
Edwin> form when the integrand has an interior singularity. The expected
Edwin> behavior occurs
Edwin> if the upper limit is 1, but not when the upper limit is 0.999999999999
Your assumption isn't quite right. It returns a noun form if the
integrand is evaluated at a bad point. When the upper limit is 1,
quad_qags evaluates the integrand at exactly 0.5. When the upper
limit is not 1, it's evaluated at a slightly different place.
quad_qags is pretty good, but it's no substitute for some analysis.
Ray