Question

I have the following:

#include <vector>
#include <complex>    

using namespace std;

vector<vector<complex> > matrix;

which is meant to be a 2D vector with complex values. The size of the structure is not known at compile time so I think a vector is a reasonable choice?

I’m using Qt.. a search didn’t reveal any matrix classes. Is there an alternative I should use? Assuming a 2D vector is a good choice. How come this happens on build:

I get the following error:

error: type/value mismatch at argument 1 in template parameter list for 
       'template<class _Tp, class _Alloc> class std::vector'
error:   expected a type, got 'complex'

Many thanks.

Answer 1

complex is a templated class, so you need to specialize it. I guess that you want either float or double:

vector<vector<complex<double> > > matrix;