The same example in Fortran-callable mode.

The program below takes the place of the data in the above example.

The User's main program and subroutine

      PROGRAM DSDQ
C             Minuit test case.  Fortran-callable.
C             Fit randomly-generated leptonic K0 decays to the
C       time distribution expected for interfering K1 and K2,
C       with free parameters Re(X), Im(X), DeltaM, and GammaS.
      IMPLICIT DOUBLE PRECISION (A-H,O-Z)
      EXTERNAL FCNK0
CC    OPEN (UNIT=6,FILE='DSDQ.OUT',STATUS='NEW',FORM='FORMATTED')
      DIMENSION NPRM(5),VSTRT(5),STP(5),ARGLIS(10)
      CHARACTER*10 PNAM(5)
      DATA NPRM /   1   ,    2   ,     5    ,   10     ,  11    /
      DATA PNAM /'Re(X)', 'Im(X)', 'Delta M','T Kshort','T Klong'/
      DATA VSTRT/   0.  ,    0.  ,    .535  ,   .892   ,  518.3 /
      DATA STP  /   0.1 ,    0.1 ,     0.1  ,     0.   ,   0.   /
C        Initialize Minuit, define I/O unit numbers
      CALL MNINIT(5,6,7)
C        Define parameters, set initial values
      ZERO = 0.
      DO 11  I= 1, 5
       CALL MNPARM(NPRM(I),PNAM(I),VSTRT(I),STP(I),ZERO,ZERO,IERFLG)
       IF (IERFLG .NE. 0)  THEN
          WRITE (6,'(A,I)')  ' UNABLE TO DEFINE PARAMETER NO.',I
          STOP
       ENDIF
   11 CONTINUE
C
      CALL MNSETI('Time Distribution of Leptonic K0 Decays')
C       Request FCN to read in (or generate random) data (IFLAG=1)
           ARGLIS(1) = 1.
      CALL MNEXCM(FCNK0, 'CALL FCN', ARGLIS ,1,IERFLG)
C
         ARGLIS(1) = 5.
      CALL MNEXCM(FCNK0,'FIX', ARGLIS ,1,IERFLG)
         ARGLIS(1) = 0.
      CALL MNEXCM(FCNK0,'SET PRINT', ARGLIS ,1,IERFLG)
      CALL MNEXCM(FCNK0,'MIGRAD', ARGLIS ,0,IERFLG)
      CALL MNEXCM(FCNK0,'MINOS', ARGLIS ,0,IERFLG)
         CALL PRTERR
         ARGLIS(1) = 5.
      CALL MNEXCM(FCNK0,'RELEASE', ARGLIS ,1,IERFLG)
      CALL MNEXCM(FCNK0,'MIGRAD', ARGLIS ,0,IERFLG)
      CALL MNEXCM(FCNK0,'MINOS', ARGLIS ,0,IERFLG)
         ARGLIS(1) = 3.
      CALL MNEXCM(FCNK0,'CALL FCN', ARGLIS , 1,IERFLG)
         CALL PRTERR
      CALL MNEXCM(FCNK0,'STOP ', 0,0,IERFLG)
      STOP
      END
 
      SUBROUTINE PRTERR
C   a little hand-made routine to print out parameter errors
      IMPLICIT DOUBLE PRECISION (A-H,O-Z)
C  find out how many variable parameters there are
      CALL MNSTAT(FMIN,FEDM,ERRDEF,NPARI,NPARX,ISTAT)
C   and their errors
      DO 50 I= 1, NPARI
      CALL MNERRS(-I,EPLUS,EMINUS,EPARAB,GLOBCC)
      WRITE (6,45) I,EPLUS,EMINUS,EPARAB,GLOBCC
   45 FORMAT (5X,I5,4F12.6)
   50 CONTINUE
      RETURN
      END

The FCN is exactly the same in Fortran-callable mode as in data-driven mode.