c     Copyright (C) 2008-2014 Vincent Eymet
c
c     KDISTRIBUTION is free software; you can redistribute it and/or modify
c     it under the terms of the GNU General Public License as published by
c     the Free Software Foundation; either version 3, or (at your option)
c     any later version.

c     KDISTRIBUTION is distributed in the hope that it will be useful,
c     but WITHOUT ANY WARRANTY; without even the implied warranty of
c     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
c     GNU General Public License for more details.

c     You should have received a copy of the GNU General Public License
c     along with KDISTRIBUTION; if not, see <http://www.gnu.org/licenses/>
c
      subroutine idx2str(idx,idx_str)
      implicit none
      include 'max.inc'
c
c     Purpose: to convert the provided integer into a character string
c     
c     Inputs:
c       + idx: value of the integer that has to be converted; allowed values
c         are 0-999
c     
c     Outputs:
c       + idx_str: value of "idx" that has been converted into a character string
c         (size of 3)
c
      integer idx
      character*1 zero_ch,idx_str1
      character*2 idx_str2
      character*3 idx_str
c     label
      integer strlen
      character*(Nchar_mx) label
      label='subroutine idx2str'

 11   format(I1)
 12   format(I2)
 13   format(I3)
      
      write(zero_ch,11) 0
      if (idx.lt.10) then
         write(idx_str1,11) idx
         idx_str=zero_ch(1:strlen(zero_ch))//
     &        zero_ch(1:strlen(zero_ch))//
     &        idx_str1(1:strlen(idx_str1))
      else if (idx.lt.100) then
         write(idx_str2,12) idx
         idx_str=zero_ch(1:strlen(zero_ch))//
     &        idx_str2(1:strlen(idx_str2))
      else if (idx.lt.1000) then
         write(idx_str,13) idx
      else
         write(*,*) 'Error from routine ',label(1:strlen(label)),' :'
         write(*,*) 'idx=',idx
         stop
      endif
      
      return
      end