! Function tao_curve_name (curve, use_region) result (curve_name)
!
! Function to return the curve name in the form:
!   plot_name.graph_name.curve_name
! For example:
!   orbit.x.c1
!
! Input:
!   curve      -- Tao_curve_struct: Curve
!   use_region -- Logical: If present and True then use the region 
!                  name instead of the plot name. Region name is
!                  'NULL_REGION' if there is no assocaited region.
!
! Output:
!   curve_name -- Character(60): Appropriate name.
!-

function tao_curve_name(curve, use_region) result (curve_name)

use tao_struct

implicit none

type (tao_curve_struct) curve
character(60) curve_name
logical, optional :: use_region

!

curve_name = '.' // trim(curve%g%name) // '.' // trim(curve%name)

if (logic_option(.false., use_region)) then
  if (associated(curve%g%p%r)) then
    curve_name = trim(curve%g%p%r%name) // trim(curve_name)
  else
    curve_name = 'NULL_REGION' // trim(curve_name)
  endif
else
    curve_name = trim(curve%g%p%name) // trim(curve_name)
endif

end function tao_curve_name