CODE Subroutine

code(3f) - [M_datapac:VECTOR_OPERATIONS] code the elements of a vector
(1 for the minimum, 2 for the next larger value, and so on)

   SUBROUTINE CODE(X,N,Y)

    REAL(kind=wp),intent(in)  :: X(:)
    INTEGER,intent(in)        :: N
    REAL(kind=wp),intent(out) :: Y(:)

CODE(3f) codes the elements of the input vector X and puts the coded
values into the output vector Y. This essentially ranks the array
elements so they can be accessed in ascending order like RANK(3f),
but allowing duplicate ranks.

The coding is as follows--

 *  the minimum is coded as 1.0.
 *  the next larger value as 2.0,
 *  the next larger value as 3.0,
 *  etc.

X   The vector of observations to be coded. The input vector X
    remains unaltered.

N   The integer number of observations in the vector X. The maximum
    allowable value of N for this subroutine is 15000.

Y   The vector Y which will contain the coded values corresponding
    to the observations in the vector X. It must be at least as large
    as X.

      o All occurrances of the minimum are coded as 1.0;
      o All occurances of the next larger value are coded as 2.0;
      o All occurances of the next larger value are coded as 3.0, etc.

program demo_code
use M_datapac, only : code
implicit none
integer,parameter            :: isz=20
real                         :: vals(isz)
real                         :: rndx(isz)
integer                      :: i
   write(*,*)' initializing array with ',isz,' random numbers'
   call random_seed()
   CALL RANDOM_NUMBER(vals)
   vals=vals*450000.0
   ! make sure some duplicates
   vals(3)=vals(6)
   vals(4)=vals(15)

   call code(vals,isz,rndx) ! code data
   ! check order
   write(*,*)
   write(*,'(2(5x,g0.10,1x))')'Values','Code',(vals(i),nint(rndx(i)),i=1,isz)

end program demo_code

 > initializing array with           20  random numbers
 >
 > Output from the code subroutine
 > Number of distinct code values =       18
 >
 >         Value     Coded Value
 >    3137.9548340          1.
 >   39334.0585938          2.
 >   58048.1054688          3.
 >   60169.2890625          4.
 >   61479.1015625          5.
 >   92335.1250000          6.
 >  101141.3671875          7.
 >  107306.5859375          8.
 >  135199.7343750          9.
 >  185223.0625000         10.
 >  214747.2656250         11.
 >  251820.6718750         12.
 >  267047.5000000         13.
 >  277210.9062500         14.
 >  296296.5625000         15.
 >  382931.3437500         16.
 >  414374.2187500         17.
 >  427620.9375000         18.
 >
 >    Values      Code
 >    277210.9062      14
 >    60169.28906      4
 >    101141.3672      7
 >    382931.3438      16
 >    61479.10156      5
 >    101141.3672      7
 >    296296.5625      15
 >    214747.2656      11
 >    3137.954834      1
 >    267047.5000      13
 >    107306.5859      8
 >    427620.9375      18
 >    414374.2188      17
 >    251820.6719      12
 >    382931.3438      16
 >    58048.10547      3
 >    39334.05859      2
 >    135199.7344      9
 >    185223.0625      10
 >    92335.12500      6

The original DATAPAC library was written by James Filliben of the
Statistical Engineering Division, National Institute of Standards
and Technology.

John Urban, 2022.05.31

CC0-1.0