module m_precision
  ! --------------------------------------------------------------------------------------

  ! --- standard precisions
  integer, parameter, public :: sp = kind(1.0)     ! Single precission
  integer, parameter, public :: dp = kind(1.D0)    ! Double precission
  !
  ! --- define working precision
  integer, parameter, public :: wp = dp   
  !
 
  ! If coded properly, to change the precission of the whole code simply 
  ! menas to redefine the wp parameter from, say, wp=sp to wp=dp!

  ! --------------------------------------------------------------------------------------
end module m_precision