C Library Functions - rank_decreasing (3)
NAME
Rank_Decreasing(3f) - [M_orderpack:RANK:UNIQUE] ranks an array in decreasing order, with duplicate entries assigned the same rank(Merge-Sort)
CONTENTS
Synopsis
Description
Options
Examples
Author
Maintainer
License
SYNOPSIS
Subroutine Rank_Decreasing (INVALS, IGOEST)
${TYPE} (kind=${KIND}), Intent (In) :: INVALS(:) Integer, Intent (Out) :: IGOEST(:)Where ${TYPE}(kind=${KIND}) may be
o Real(kind=real32) o Real(kind=real64) o Integer(kind=int8) o Integer(kind=int16) o Integer(kind=int32) o Integer(kind=int64) o Character(kind=selected_char_kind("DEFAULT"),len=*)
DESCRIPTION
RANK_DECREASING(3f) generates an inverse ranking of an array, but with duplicate entries assigned the same rank.
Internally, the routine is similar to pure merge-sort ranking, but on the last pass, it sets indices in IGOEST to the rank of the original value in an ordered set with duplicates removed. For performance reasons, the first two passes are taken out of the standard loop, and use dedicated coding.
OPTIONS
INVALS array to rank IGOEST returned rank array
EXAMPLES
Sample program:
program demo_rank_decreasing ! rank input array ranking duplicates the same use M_orderpack, only : rank_decreasing implicit none character(len=*),parameter :: fmt=’(a,*(g3.3,1x))’ integer,allocatable,dimension(:) :: INVALS, igoest, distinct, count integer :: imx, i ! create an input array INVALS=[11, 11, 22, 11, 33, 33, 22, 33, 33] ! make an index array of the same size if(allocated(igoest))deallocate(igoest) allocate(igoest(size(INVALS))) print fmt, ’Original: ’,INVALS print fmt, ’Number of indices to sort:’,size(INVALS) ! rank input array ranking duplicates the same call rank_decreasing(INVALS,igoest) print fmt, ’Returned Indices: ’,igoest(:) ! ! interrogate the results ! imx=maxval(igoest) print fmt, ’Number of unique indices :’,imx ! squeeze it down to just IMX unique values count=[(0,i=1,imx)] ! count how many times a value occurs distinct=count ! array to set of unique values do i=1,size(INVALS) distinct(igoest(i))=INVALS(i) count(igoest(i))= count(igoest(i))+1 enddo print fmt, ’Sorted unique values: ’,distinct print fmt, ’count of occurrences: ’,count end program demo_rank_decreasingResults:
Original: 11 11 22 11 33 33 22 33 33 Number of indices to sort: 9 Returned Indices: 1 1 2 1 3 3 2 3 3 Number of unique indices : 3 Sorted unique values: 11 22 33 count of occurrences: 3 2 4
AUTHOR
Michel Olagnon, 2000-2012
MAINTAINER
John Urban, 2022.04.16
LICENSE
CC0-1.0
| Nemo Release 3.1 | rank_decreasing (3) | February 23, 2025 |
