pic_sorting_sort_index

The generic subroutine implementing the SORT_INDEX algorithm to return an index array whose elements would sort the input array in the desired direction. It is primarily intended to be used to sort a derived type array based on the values of a component of the array. Its use has the syntax:

 call sort_index( array, index[, work, iwork, reverse ] )

with the arguments:

array: the rank 1 array to be sorted. It is an intent(inout) argument of any of the types integer(int8), integer(int16), integer(int32), integer(int64), real(real32), real(real64), real(real128), character(*), type(string_type), type(bitset_64), type(bitset_large). If both the type of array is real and at least one of the elements is a NaN, then the ordering of the array and index results is undefined. Otherwise it is defined to be as specified by reverse.
index: a rank 1 array of sorting indices. It is an intent(out) argument of the type integer(int_index). Its size shall be the same as array. On return, if defined, its elements would sort the input array in the direction specified by reverse.
work (optional): shall be a rank 1 array of the same type as array, and shall have at least size(array)/2 elements. It is an intent(out) argument to be used as “scratch” memory for internal record keeping. If associated with an array in static storage, its use can significantly reduce the stack memory requirements for the code. Its value on return is undefined.
iwork (optional): shall be a rank 1 integer array of kind int_index, and shall have at least size(array)/2 elements. It is an intent(out) argument to be used as “scratch” memory for internal record keeping. If associated with an array in static storage, its use can significantly reduce the stack memory requirements for the code. Its value on return is undefined.
reverse (optional): shall be a scalar of type default logical. It is an intent(in) argument. If present with a value of .true. then index will sort array in order of non-increasing values in stable order. Otherwise index will sort array in order of non-decreasing values in stable order.

Examples

Sorting a related rank one array:

    subroutine sort_related_data( a, b, work, index, iwork )
        ! Sort `b` in terms or its related array `a`
        integer, intent(inout)         :: a(:)
        integer(int32), intent(inout)  :: b(:) ! The same size as a
        integer(int32), intent(out)    :: work(:)
        integer(int_index), intent(out) :: index(:)
        integer(int_index), intent(out) :: iwork(:)
    ! Find the indices to sort a
        call sort_index(a, index(1:size(a)),&
            work(1:size(a)/2), iwork(1:size(a)/2))
    ! Sort b based on the sorting of a
        b(:) = b( index(1:size(a)) )
    end subroutine sort_related_data

Sorting a rank 2 array based on the data in a column

    subroutine sort_related_data( array, column, work, index, iwork )
    ! Sort `a_data` in terms or its component `a`
        integer, intent(inout)         :: a(:,:)
        integer(int32), intent(in)     :: column
        integer(int32), intent(out)    :: work(:)
        integer(int_index), intent(out) :: index(:)
        integer(int_index), intent(out) :: iwork(:)
        integer, allocatable           :: dummy(:)
        integer :: i
        allocate(dummy(size(a, dim=1)))
    ! Extract a component of `a_data`
        dummy(:) = a(:, column)
    ! Find the indices to sort the column
        call sort_index(dummy, index(1:size(dummy)),&
                        work(1:size(dummy)/2), iwork(1:size(dummy)/2))
    ! Sort a based on the sorting of its column
        do i=1, size(a, dim=2)
            a(:, i) = a(index(1:size(a, dim=1)), i)
        end do
    end subroutine sort_related_data

Sorting an array of a derived type based on the dsta in one component

    subroutine sort_a_data( a_data, a, work, index, iwork )
    ! Sort `a_data` in terms or its component `a`
        type(a_type), intent(inout)    :: a_data(:)
        integer(int32), intent(inout)  :: a(:)
        integer(int32), intent(out)    :: work(:)
        integer(int_index), intent(out) :: index(:)
        integer(int_index), intent(out) :: iwork(:)
    ! Extract a component of `a_data`
        a(1:size(a_data)) = a_data(:) % a
    ! Find the indices to sort the component
        call sort_index(a(1:size(a_data)), index(1:size(a_data)),&
                        work(1:size(a_data)/2), iwork(1:size(a_data)/2))
    ! Sort a_data based on the sorting of that component
        a_data(:) = a_data( index(1:size(a_data)) )
    end subroutine sort_a_data

Uses

- Ancestors:
- pic_sorting
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Variables

Type	Visibility	Attributes		Name		Initial
integer,	private,	parameter	::	max_merge_stack	=	int(ceiling(log(2._dp**64)/log(1.6180339887_dp)))

Derived Types

type :: run_type

Used to pass state around in a stack among helper functions for the ORD_SORT and SORT_INDEX algorithms

Components

Type	Visibility	Attributes		Name		Initial
integer(kind=int_index),	public		::	base	=	0
integer(kind=int_index),	public		::	len	=	0

Module Subroutines

module subroutine char_sort_index_default(array, index, work, iwork, reverse)

Arguments

Type	Intent	Optional		Name
character(len=*),	intent(inout)		::	array(0:)
integer(kind=int_index),	intent(out)		::	index(0:)
character(len=len),	intent(out),	optional	::	work(0:)
integer(kind=int_index),	intent(out),	optional	::	iwork(0:)
logical,	intent(in),	optional	::	reverse

module subroutine char_sort_index_low(array, index, work, iwork, reverse)

Arguments

Type	Intent	Optional		Name
character(len=*),	intent(inout)		::	array(0:)
integer(kind=int_index_low),	intent(out)		::	index(0:)
character(len=len),	intent(out),	optional	::	work(0:)
integer(kind=int_index_low),	intent(out),	optional	::	iwork(0:)
logical,	intent(in),	optional	::	reverse

module subroutine dp_sort_index_default(array, index, work, iwork, reverse)

Arguments

Type	Intent	Optional		Name
real(kind=dp),	intent(inout)		::	array(0:)
integer(kind=int_index),	intent(out)		::	index(0:)
real(kind=dp),	intent(out),	optional	::	work(0:)
integer(kind=int_index),	intent(out),	optional	::	iwork(0:)
logical,	intent(in),	optional	::	reverse

module subroutine dp_sort_index_low(array, index, work, iwork, reverse)

Arguments

Type	Intent	Optional		Name
real(kind=dp),	intent(inout)		::	array(0:)
integer(kind=int_index_low),	intent(out)		::	index(0:)
real(kind=dp),	intent(out),	optional	::	work(0:)
integer(kind=int_index_low),	intent(out),	optional	::	iwork(0:)
logical,	intent(in),	optional	::	reverse

module subroutine int32_sort_index_default(array, index, work, iwork, reverse)

Arguments

Type	Intent	Optional		Name
integer(kind=int32),	intent(inout)		::	array(0:)
integer(kind=int_index),	intent(out)		::	index(0:)
integer(kind=int32),	intent(out),	optional	::	work(0:)
integer(kind=int_index),	intent(out),	optional	::	iwork(0:)
logical,	intent(in),	optional	::	reverse

module subroutine int32_sort_index_low(array, index, work, iwork, reverse)

Arguments

Type	Intent	Optional		Name
integer(kind=int32),	intent(inout)		::	array(0:)
integer(kind=int_index_low),	intent(out)		::	index(0:)
integer(kind=int32),	intent(out),	optional	::	work(0:)
integer(kind=int_index_low),	intent(out),	optional	::	iwork(0:)
logical,	intent(in),	optional	::	reverse

module subroutine int64_sort_index_default(array, index, work, iwork, reverse)

Arguments

Type	Intent	Optional		Name
integer(kind=int64),	intent(inout)		::	array(0:)
integer(kind=int_index),	intent(out)		::	index(0:)
integer(kind=int64),	intent(out),	optional	::	work(0:)
integer(kind=int_index),	intent(out),	optional	::	iwork(0:)
logical,	intent(in),	optional	::	reverse

module subroutine int64_sort_index_low(array, index, work, iwork, reverse)

Arguments

Type	Intent	Optional		Name
integer(kind=int64),	intent(inout)		::	array(0:)
integer(kind=int_index_low),	intent(out)		::	index(0:)
integer(kind=int64),	intent(out),	optional	::	work(0:)
integer(kind=int_index_low),	intent(out),	optional	::	iwork(0:)
logical,	intent(in),	optional	::	reverse

module subroutine sp_sort_index_default(array, index, work, iwork, reverse)

Arguments

Type	Intent	Optional		Name
real(kind=sp),	intent(inout)		::	array(0:)
integer(kind=int_index),	intent(out)		::	index(0:)
real(kind=sp),	intent(out),	optional	::	work(0:)
integer(kind=int_index),	intent(out),	optional	::	iwork(0:)
logical,	intent(in),	optional	::	reverse

module subroutine sp_sort_index_low(array, index, work, iwork, reverse)

Arguments

Type	Intent	Optional		Name
real(kind=sp),	intent(inout)		::	array(0:)
integer(kind=int_index_low),	intent(out)		::	index(0:)
real(kind=sp),	intent(out),	optional	::	work(0:)
integer(kind=int_index_low),	intent(out),	optional	::	iwork(0:)
logical,	intent(in),	optional	::	reverse

pic_sorting_sort_index Submodule

Contents

Variables

Derived Types

Module Subroutines

Examples

Uses

Ancestors:

Variables

Derived Types

type :: run_type

Components

Module Subroutines

module subroutine char_sort_index_default(array, index, work, iwork, reverse)

Arguments

module subroutine char_sort_index_low(array, index, work, iwork, reverse)

Arguments

module subroutine dp_sort_index_default(array, index, work, iwork, reverse)

Arguments

module subroutine dp_sort_index_low(array, index, work, iwork, reverse)

Arguments

module subroutine int32_sort_index_default(array, index, work, iwork, reverse)

Arguments

module subroutine int32_sort_index_low(array, index, work, iwork, reverse)

Arguments

module subroutine int64_sort_index_default(array, index, work, iwork, reverse)

Arguments

module subroutine int64_sort_index_low(array, index, work, iwork, reverse)

Arguments

module subroutine sp_sort_index_default(array, index, work, iwork, reverse)

Arguments

module subroutine sp_sort_index_low(array, index, work, iwork, reverse)

Arguments