program pwinput
	character	cFile*80
	character	cPTN*3		/'PTN'/
	character	cPTR*3		/'PTR'/
	character	cPWN*3		/'PWN'/
	character	cPWR*3		/'PWR'/
	character	cValPTN*2
	character	cValPTR*2
	character	cValPWN*2
	character	cValPWR*2
	character	cSay*6		/'pwloop'/

	logical		bOpen
	logical		bOpenFile

	include		'dirspec.h'
	include		'openfile.h'

	!-------	Start values for parameters

	PWR0 = -1.
	PWN0 = 0.

	!-------	Increments for parameters

	dPWR = .1
	dPWN = .1

	!-------
	! The maximum loop index for each parameter is stored in the symbols
	! cPTN and cPTR. These symbols are defined in the bash script 'pwscript'.
	! If they are not defined, exit with status code 2 (ERROR).

	if (iGetSymbol(cPTN,cValPTN) .eq. 0) call Say(cSay,'E','PTN','not defined') 

	if (iGetSymbol(cPTR,cValPTR) .eq. 0) call Say(cSay,'E','PTR','not defined') 

	!-------
	! Read the maximum loop index from string into integer variables
	! The loop index runs from 0 to iValPTN and 0 to iValPTR respectively.

	read (cValPTN,'(I2.2)') iValPTN
	read (cValPTR,'(I2.2)') iValPTR

	!-------
	! The current value of the loop index is stored in symbols cPWN and cPWR
	! If these symbols exist then read them. If any one of the symbols does not
	! exist then initialize the loop variables.
	! Note that iValPWN corresponds to the inner loop and iValPWR to the outer loop.

	if (iGetSymbol(cPWN,cValPWN) .eq. 0 .or.
     &      iGetSymbol(cPWR,cValPWR) .eq. 0) then

	    !-------
	    ! Initialize all loop indices to their maximum value.

	    iValPWN = iValPTN
	    iValPWR = iValPTR
	else
	    read (cValPWN,'(I2)') iValPWN
	    read (cValPWR,'(I2)') iValPWR
	end if

	iValPWN = iValPWN+1			! Increase inner loop index
	if (iValPWN .gt. iValPTN) then		! If out of range
	    iValPWN = 0				! .. reset to zero
	    iValPWR = iValPWR+1			! .. increment outer loop index
	end if

	if (iValPWR .gt. iValPTR) then
	    iValPWR = 0
	end if

	!-------
	! Calculate the values of all parameters.

	PWN = PWN0+iValPWN*dPWN
	PWR = PWR0+iValPWR*dPWR

	i = iFilePath(cEnvi//'temp',0,' ','ipsg2.input',cFile)

	i = OPN__TEXT+OPN__REOPEN+OPN__UNKNOWN
	bOpen = bOpenFile(i,iU,cFile,iRec)
	if (bOpen) then
	    write (iU,'(A)') 'NO'
	    write (iU,'(A)') '18'
	    write (iU,'(A)') '-2.5'
	    write (iU,'(A)') 'velocity'
	    write (iU,'(A)') 'Nagoya'
	    write (iU,'(A)') 'NO'
	    if (PWN .lt. 0) then
		write (iU,'(F5.2)') PWN
	    else
		write (iU,'(F4.2)') PWN
	    end if
	    if (PWR .lt. 0) then
		write (iU,'(F5.2)') PWR
	    else
		write (iU,'(F4.2)') PWR
	    end if
	    write (iU,'(A)') 'NO'
	    write (iU,'(A)') '4'
	    write (iU,'(A)') '9'
	    write (iU,'(A)') 'all'
	    write (iU,'(A)') '5'
	    write (iU,'(A)') '180'
	    write (iU,'(A)') '90'
	    write (iU,'(A)') '1895'
	    write (iU,'(A)') '3'
	    write (iU,'(A)') 'UL'
	    write (iU,'(A)') 'NO'
	    write (iU,'(A)') '2449780.5'
	    write (iU,'(A)') '320'
	    iU = iFreeLun(iU)
	end if

	write (cValPWN,'(I2.2)') iValPWN
	write (cValPWR,'(I2.2)') iValPWR

	i = iSetSymbol(cPWN,cValPWN,1)
	i = iSetSymbol(cPWR,cValPWR,1)

	if (bOpen) then
	    call Say(cSay,'S','STOP',' ') 	! Exit code 1
	else
	    call Say(cSay,'W','STOP',' ') ! Exit code 0
	end if

	end