Fitting one or multi-demensional arrays

CALL HFITV (N,NDIM,NVAR,X,Y,EY,FUN,CHOPT,NP,*PAR*,STEP,PMIN,PMAX,SIGPAR*, CHI2*)

Action: Fits a given parametric function to a number of value pairs with associated errors.

Input parameters:

N

Number of points to be fitted.

NDIM

Declared first dimension of array X.

NVAR

Dimension of the distribution.

X

Array of dimension N containing the X-coordinates of the points to be fitted.

Y

Array of dimension N containing the Y-coordinates of the points to be fitted.

EY

Array of dimension N containing the errors on the Y-coordinates of the points to be fitted.

FUN

Parametric function (to be declared EXTERNAL)

CHOPT

Character variable specifying the desired options.

'B'

Some or all parameters are bounded. The arrays STEP, PMIN and PMAX must be specified. By default all parameters vary freely.

'D'

The user provides the derivatives of the function analytically with the user routine HDERIV. By default derivatives are computed numerically.

'E'

Perform a detailed error analysis using the MINUIT routines

'L'

Use the logaritnic Likelihood fitting method. By default the chisquared method is used.

'M'

Invoke interactive MINUIT.

'Q'

Quiet mode. No printing.

'U'

User function value is taken from /HCFITD/FITPAD(24),FITFUN,   see section . All calculations are performed in double precision.

'V'

Verbose mode. Results are printed after each iteration. By default only final results are printed.

'W'

Set the event weights equal to one. By default weights are taken according to statistical errors. HESSE and MINOS

NP

Number of parameters (NP$\leq$25).

PAR

Array of dimension NP with initial values for the parameters.

STEP

Array of dimension NP with initial step sizes for the parameters ('B' option only).

PMIN

Array of dimension NP with the lower bounds for the parameters ('B' option only).

PMAX

Array of dimension NP with the upper bounds for the parameters ('B' option only).

Output parameters:

PAR

Array of dimension NP with the final fitted values of the parameters.

SIGPAR

Array of dimension NP with the standard deviations on the final fitted values of the parameters.

CHI2

Chisquared of the fit.