Hello,

There appears to have been a change in eigen that makes the following code behave differently in 3.3

Code: Select all

Eigen::SparseMatrix<double> m(3, 3);
m.setIdentity();
assert(m.col(1).innerIndexPtr()[0] == 1);


I would expect the innerIndexPtr() of the second column to start with "1" but it returns "0".
col(i).innerIndexPtr() always returns the m.innerIndexPtr().
Could this be a bug?

Best regards,
João

This is intentional. You're not supposed to use innerIndexPtr without using outerIndexPtr first to find where to look in innerIndexPtr. So the correct code is:

assert(m.col(1).innerIndexPtr()[ m.col(1).outerIndexPtr()[0] ] == 1);

I see!
Thank you!