convert_to_dense Module Subroutine

  module subroutine convert_to_dense(this)
    !! Convert the graph to a dense representation.
    implicit none

    ! Arguments
    class(graph_type), intent(inout) :: this
    !! Parent. Instance of the graph structure.

    ! Local variables
    integer :: v, e, i, j, idx
    !! Loop indices.

    if(.not.this%is_sparse) return

    this%is_sparse = .false.

    if(allocated(this%vertex_features)) deallocate(this%vertex_features)
    if(allocated(this%edge_features)) deallocate(this%edge_features)
    if(allocated(this%edge_weights)) deallocate(this%edge_weights)

    allocate(this%vertex(this%num_vertices))
    allocate(this%edge(this%num_edges))

    do v = 1, this%num_vertices
       idx = this%vertex(v)%id
       if(idx.eq.-1) idx = v
       this%vertex(v)%feature = this%vertex_features(:,idx)
       this%vertex(v)%id = v
    end do

    do e = 1, this%num_edges
       idx = this%edge(e)%id
       if(idx.eq.-1) idx = e
       this%edge(e)%feature = this%edge_features(:,idx)
       this%edge(e)%weight = this%edge_weights(idx)
       this%edge(e)%id = e
    end do

    if(allocated(this%adjacency)) deallocate(this%adjacency)
    allocate(this%adjacency(this%num_vertices, this%num_vertices))
    this%adjacency = 0
    do i = 1, size(this%adj_ia, dim=1)-1
       do j = this%adj_ia(i), this%adj_ia(i+1)-1
          this%adjacency(i,this%adj_ja(1,j)) = this%adj_ja(2,j)
       end do
    end do

    deallocate(this%vertex_features)
    deallocate(this%edge_features)
    deallocate(this%edge_weights)
    deallocate(this%adj_ia)
    deallocate(this%adj_ja)

  end subroutine convert_to_dense