dsort Subroutine

private subroutine dsort(n, Kflag, Dx, Dy)

Sort an array and optionally make the same interchanges in an auxiliary array. The array may be sorted in increasing or decreasing order.

History

  • 29-dec-2022 : Replaced original routines. Now just a wraper for sort_ascending recursive quicksort (JW)

Arguments

Type IntentOptional Attributes Name
integer, intent(in) :: n

number of values in array DX to be sorted
integer, intent(in) :: Kflag

control parameter: * Kflag < 0 : sort DX in decreasing order and optionally carry DY along. * Kflag > 0 : sort DX in increasing order and optionally carry DY along.
real(kind=wp), intent(inout), dimension(*) :: Dx

array of values to be sorted (usually abscissas)
real(kind=wp), intent(inout), optional, dimension(*) :: Dy

array to be (optionally) carried along

Calls

proc~~dsort~~CallsGraph proc~dsort dsort proc~sort_ascending sort_ascending proc~dsort->proc~sort_ascending

Called by

proc~~dsort~~CalledByGraph proc~dsort dsort proc~defcmn defcmn proc~defcmn->proc~dsort proc~dfcmn dfcmn proc~dfcmn->proc~dsort proc~defc defc proc~defc->proc~defcmn proc~dfc dfc proc~dfc->proc~dfcmn

Source Code

   subroutine dsort(n, Kflag, Dx, Dy)
      implicit none

      integer, intent(in) :: n !! number of values in array DX to be sorted
      integer, intent(in) :: Kflag !! control parameter:
                                   !!  * Kflag < 0 : sort DX in decreasing order and optionally carry DY along.
                                   !!  * Kflag > 0 : sort DX in increasing order and optionally carry DY along.
      real(wp), dimension(*), intent(inout) :: Dx !! array of values to be sorted   (usually abscissas)
      real(wp), dimension(*), intent(inout), optional :: Dy !! array to be (optionally) carried along

      if (n < 1) then
         write (*, *) 'The number of values to be sorted is not positive.'
         return
      end if

      if (abs(Kflag) == 0) then
         write (*, *) 'The sort control parameter, K, cannot be 0.'
         return
      end if

      ! Alter array DX to get decreasing order if needed
      if (Kflag < 0) Dx(1:n) = -Dx(1:n)
      call sort_ascending(n, Dx, Dy)
      if (Kflag < 0) Dx(1:n) = -Dx(1:n)

   end subroutine dsort