c-----------------------------------------------------------------------
c             --------                               ------
c             function                               source
c             --------                               ------
c-----------------------------------------------------------------------
c
        double precision function source(x,y)
c--------------------------------------------
c
        double precision  x, y, phi
c
        common /constantes/ phi
c
c
c       -------------
c       Fonte externa
c--------------------
        source = ( 2.0d0*phi*phi )*dsin(phi*x)*dcos(phi*y)
c
c
c
        return
        end
c-----------------------------------------------------------------------
c-----------------------------------------------------------------------
c--------------------------------------------------
c       Petronio Pulino
c       Departamento de Matematica Aplicada - D.M.A
c       IMECC - UNICAMP
c       e-mail: pulino@ime.unicamp.br
c         http://www.ime.unicamp.br/~pulino/
c--------------------------------------------------
