问题
in eigen, the construct:
(R.array() < s).select(P,Q);
works when either one or both of P,Q are vectors (of the same length as R). But as soon as both of them are scalars, I get a compilation error.
My question is; is the behavior of select in the presence
of two scalars a way for eigen to warn me that
there are more efficient constructs? If so, what are they?
回答1:
You can workaround by using VectorXd::Constant(size,value) for one argument.
来源：https://stackoverflow.com/questions/21440511/strange-behavior-of-eigenselect