I need to compute the eigenvalues of a Matrix. On Stackoverflow, I found that the following lines of Code would work:

Matrix<double> processedData = Matrix<double>.Build.Random(5,5);
Evd<double> eigen = processedData.Evd();
Vector<Complex> eigenvector = eigen.EigenValues;

I tried to include the following and many others: 

using MathNet.Numerics
using MathNet.Numerics.LinearAlgebra
using MathNet.Numerics.LinearAlgebra.Factorization

Still I get the error: 'the type or namespace 'Complex' could not be found...'

Has anyone worked with eigenvalues / Complex Vectors and could help me please? 

Thank you!