# Finite Difference Frequency Domain

Hello everybody!
I am trying to construct the FDFD method for 3D structures. I have already constructed the general formulation and specifically I have set the complete matrix form. Due to the fact that the matrices are too sparse, and my system is out of memory, I am trying to set the problem in a dense mode.
To be more specific I want to transform the sparse matrices into dense form and to solve the problem efficiently. I have developed the problem in fortran, so I would like to ask you if anybody knows any library, which I can use in order to achieve this transformation. I know for example that in matlab using the sparse() routine I can achieve this goal. Is there any similar routine in fortran?