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diff --git a/math/nlfit/doc/nlinit.hlp b/math/nlfit/doc/nlinit.hlp new file mode 100644 index 00000000..94e5e5a9 --- /dev/null +++ b/math/nlfit/doc/nlinit.hlp @@ -0,0 +1,86 @@ +.help nlinit Feb91 "Nlfit Package" +.ih +NAME +nlinit -- initialise curve descriptor +.ih +SYNOPSIS +include <math/nlfit.h> + +nlinit[rd] (nl, fnc, dfnc, params, dparams, nparams, plist, nfparams, + tol, itmax) + +.nf +pointer nl # curve descriptor +int fnc # address of first user-supplied function +int dfnc # address of second user-supplied function +real/double params[nparams] # list of initial parameter values +real/double dparams[nparams]# list of parameter increments +int nparams # number of parameters +int plist[nparams] # list of parameters to be fit +int nfparams # number of parameters to be fit +real/double tol # fitting tolerance +int itmax # maximum number of iterations +.fi +.ih +ARGUMENTS +.ls nl +Pointer to the curve descriptor structure. +.le +.ls fnc +The address of the user-supplied subroutine fncname for evaluating the function +to be fit. The calling sequence of fncname is the following. + +.nf +fncname (x, nvars, params, nparams, zfit) +.fi +.le +.ls dfnc +The address of the user-supplied subroutine dfncname for evaluating the +function to be fit and its derivatives with respect to the parameters. +The calling sequence of dfncname is the following. + +.nf +dfncname (x, nvars, params, dparams, nparams, zfit, derivs) +.fi +.le +.ls params +An array containing initial values of all the parameters, including both +those to be fit and those that are to be held constant. +.le +.ls dparams +An array parameter increment values over which the derivatives are to be +computed empirically. If equations are supplied for the derivatives +inside dfnc, the dparams array is not used. +.le +.ls nparams +The total number of parameters in the user-supplied function. +.le +.ls plist +The list of parameters to be fit. Plist is an integer array containing +the indices of those parameters in params to be fit. +.le +.ls nfparams +The total number of parameters to be fit. +.le +.ls tol +The fitting tolerance. If the difference in the chi-squared +from one iteration to the next is less than the fitting tolerance +times the current chi-squared, the fit has converged. +.le +.ls itmax +The maximum number of fitting iterations. Itmax must be greater than +or equal to 3. +.le +.ih +DESCRIPTION +Allocate space for the curve descriptor structure and the arrays and +vectors used by the numerical routines. Initialize all arrays and vectors +to zero. Return the curve descriptor to the calling routine. +.ih +NOTES +NLINIT must be the first NLFIT routine called. NLINIT returns a NULL pointer +if it encounters an illegal parameter list. +.ih +SEE ALSO +nlfree +.endhelp |