*** empty log message ***

davidson.h

@@ -0,0 +1,9 @@
+
+//Davidson diagonalization of real symmetric matrix
+
+//matrix can be any class which provides nrows(), diagonalof() and operator*(const  NRVec<T>) methods
+//does not even have to be explicitly stored - direct CI
+//n<0 highest eigenvalues, n>0 lowest eigenvalues
+
+template <class T, class matrix>
+extern void davidson(const matrix &a, NRVec<T> *vecs /*input-output*/, T *vals, const int n=1, const double eps=1e-10);