anchor.diff:  !      region based
   !      depth based
   !      constant value from geoclaw_module
  -!    
  +!
   ! ==============================================================================
   
   module friction_module
   
       implicit none
       save
  -
  -    logical, private :: module_setup = .false.
   
       ! Parameters
       integer, public, parameter :: friction_index = 4
  
positive.code: 
      end subroutine set_friction_field
  
  
      ! ==========================================================================
      !  read_friction_file - Reads an input file containing info on friction
      !    coefficients.
      ! ==========================================================================
      type(friction_file_type) function read_friction_file(path, file_type) result(file)
          
          implicit none
  
          ! Path to file to be read in
  
negative.code:             ! Assumes a uniform rectangular grid of data values.
              case(1)
                  stop "Unimplemented file type for friction files."
  
              ! ================================================================
              ! ASCII file with header followed by z data
              ! (progressing from upper left corner across rows, then down)
  