PROGRAM HEURISTIC5
C This program reads in a 2-column file putting the values into
C arrays A and B.
C The first value from array B is subtracted off all the other values
C of B, then stored in array C. Array C is then written to disk, keeping
C the original array A as the first column.
C ..........................
	PARAMETER (NMAX=2000)
	REAL A(NMAX), B(NMAX), C(NMAX)
	REAL B0
	CHARACTER*50 INPUTFILE, OUTPUTFILE
C ..........................
	WRITE(*,'(A,$)') 'Enter the name of the INPUT file : '
	READ (*,'(A)') INPUTFILE
	WRITE(*,'(A,$)') 'Enter the name of the OUTPUT FILE: '
	READ (*,'(A)') OUTPUTFILE

	IERR = 0
	NDATA = NMAX
	CALL GET_DATA (INPUTFILE, ndata, a, b, ierr)
	
	B0 = B(1)
	DO I=1, NDATA
		C(I) = B(I) - B0
	END DO

	IERR = 0
	CALL WRITE_DATA( OUTPUTFILE, NDATA, A, C, IERR)
C ..........................
	STOP 'HEURISTIC5 finished.'
	END
C-----------------------------------------------------------------
C Notice the format of the write statement. The syntax '(A)' is used
C to read/write a character variable string of unknown length.
C The '(A,$)' contains a special symbol, the '$', to tell the output
C not to carriage-return. It makes for nicer looking I/O.