I just started using the newest version of eigen ("sudo apt-get install libeigen3-dev" on ubuntu). I think the version I was using before was Eigen 2.[something].

Some things appear to have vanished since the version I used before, although they are still in the online documentation. So far I've found a way around it except for the following:

I need to find the log of a determinant, and have done it the following way before in order to avoid very large/small values:

Code: Select all

Eigen::MatrixXcd Mat=setupMat();
Eigen::PartialPivLU<Eigen::MatrixXcd> LU(Mat);
Eigen::MatrixXcd U=LU.matrixLU().triangularView<Eigen::Upper>();
complex<double> log_det=0;
for(int i=0;i<n;i++) det+=log(U(i,i));
det+=log(complex<double>(LU.permutationP().determinant()));


where "setupMat()" is a function I've defined, and "LU.permutationP().determinant()" is necessary to get the sign of the determinant.

This worked fine up until now, where I get the compiler error

Code: Select all

error: ‘const PermutationType’ has no member named ‘determinant’


Although "determinant()" still there in the documentation: http://eigen.tuxfamily.org/dox/classEigen_1_1PermutationBase.html#a021fa8725bf6224f20a8670afabb6bcd

So far I haven't thought of an efficient way to get the sign of the determinant. Using "indices()" seems like it would be slow. Any ideas?

I don't think you were using Eigen2: In Eigen2 there is no PartialPivLU, no PermutationMatrix, etc. You were more likely using the devel branch (3.3). To get the determinant of a permutation matrix, you need latest 3.2 and devel branch.

Oh I see, thanks. Is there a way to get the devel branch through apt-get or do I have to do it the old fashioned way?

debian ships the 3.3-beta1 version which is likely compatible with ubuntu.

Ok. When you say "ships" do you mean through a package manager? Apparently not apt-get?