subroutine num2str(num,str,error)
      implicit none
      include 'max.inc'
      include 'formats.inc'
c
c     Purpose: to convert an integer to a character string
c
c     Input:
c       + num: integer
c     
c     Output:
c       + str: character string
c       + error: a value of zero means conversion is OK; a value of 1 means "num"
c                was not recognized.
c

c     I/O
      integer num
      character*(Nchar_mx) str
      integer error
c     temp
      integer absnum,sign
      character*(Nchar_mx) f
      integer strlen
      character*(Nchar_mx) label
      label='subroutine num2str'

      if (num.lt.0) then
         sign=-1
      else
         sign=1
      endif
      absnum=abs(num)
      
      error=0
      if ((absnum.ge.0).and.(absnum.lt.10)) then
         write(str,11) absnum
      else if ((absnum.ge.10).and.(absnum.lt.100)) then
         write(str,12) absnum
      else if ((absnum.ge.100).and.(absnum.lt.1000)) then
         write(str,13) absnum
      else if ((absnum.ge.1000).and.(absnum.lt.10000)) then
         write(str,14) absnum
      else if ((absnum.ge.10000).and.(absnum.lt.100000)) then
         write(str,15) absnum
      else if ((absnum.ge.100000).and.(absnum.lt.1000000)) then
         write(str,16) absnum
      else if ((absnum.ge.1000000).and.(absnum.lt.10000000)) then
         write(str,17) absnum
      else if ((absnum.ge.10000000).and.(absnum.lt.100000000)) then
         write(str,18) absnum
      else if ((absnum.ge.100000000).and.(absnum.lt.1000000000)) then
         write(str,19) absnum
      else
         error=1
         goto 666
      endif

      if (sign.eq.-1) then
         str="-"//str(1:strlen(str))
      endif
      
 666  continue
      return
      end



      subroutine num2str3(num,str3)
      implicit none
      include 'max.inc'
c
c     Purpose: to convert an integer to a character string of size 3
c
c     Input:
c       + num: integer
c     
c     Output:
c       + str3: character string
c

c     I/O
      integer num
      character*3 str3
c     temp
      character*(Nchar_mx) str_tmp
      integer err_code
      integer strlen
      character*(Nchar_mx) label
      label='subroutine num2str3'

      call num2str(num,str_tmp,err_code)
      if (err_code.eq.1) then
         call error(label)
         write(*,*) 'Problem converting to character string'
         write(*,*) 'num=',num
         stop
      endif

      if (num.lt.10) then
         str3='00'//
     &        str_tmp(1:strlen(str_tmp))
      else if (num.lt.100) then
         str3='0'//
     &        str_tmp(1:strlen(str_tmp))
      else if (num.lt.1000) then
         str3=str_tmp(1:strlen(str_tmp))
      else
         call error(label)
         write(*,*) 'unable to convert:'
         write(*,*) 'num=',num,' > 1000'
         write(*,*) 'to a string of 3 characters'
         stop
      endif

      return
      end




      subroutine num2str2(num,str2)
      implicit none
      include 'max.inc'
c
c     Purpose: to convert an integer to a character string of size 2
c
c     Input:
c       + num: integer
c     
c     Output:
c       + str2: character string
c

c     I/O
      integer num
      character*2 str2
c     temp
      character*(Nchar_mx) str_tmp
      integer err_code
      integer strlen
      character*(Nchar_mx) label
      label='subroutine num2str2'

      call num2str(num,str_tmp,err_code)
      if (err_code.eq.1) then
         call error(label)
         write(*,*) 'Problem converting to character string'
         write(*,*) 'num=',num
         stop
      endif

      if (num.lt.10) then
         str2='0'//
     &        str_tmp(1:strlen(str_tmp))
      else if (num.lt.100) then
         str2=str_tmp(1:strlen(str_tmp))
      else
         call error(label)
         write(*,*) 'unable to convert:'
         write(*,*) 'num=',num,' > 100'
         write(*,*) 'to a string of 2 characters'
         stop
      endif

      return
      end