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diff --git a/pkg/xtools/inlfit/README b/pkg/xtools/inlfit/README new file mode 100644 index 00000000..56d72836 --- /dev/null +++ b/pkg/xtools/inlfit/README @@ -0,0 +1,165 @@ + THE INLFIT PACKAGE + +This subdirectory contains the routines of the interactive non-linear +least squares fitting package INLFIT. This package is layered on the NLFIT +package in MATH. NLFIT uses the Levenberg-Marquardt method to solve for +the parameters of a user specified non-linear equation. The user must supply +two routines. The first routine evaluates the function in terms of its +parameters. The second routine evaluates the function and its derivatives +in terms of its parameters. The user must also supply initial guesses for +the parameters and parameter increments, the list of parameters to be +varied during the fitting process, a fitting tolerance, and the maximum +number of iterations. + +The entry points into the INLFIT package are listed below. + + ininit - Initialize the fitting routines + inget - Get the value of an INLFIT parameter + input - Store the value of an INLFIT parameter + ingkey - Get the value of an INLFIT graphics/axis parameter + inpkey - Store the value of an INLFIT graphics/axis parameter + infit - Fit the function non-interactively + ingfit - Fit the function interactively + inerrors - Compute the errors of the fit + infree - Free memory allocated by ininit + +The calling sequences for the above routines are listed below. The [iprd] +stand for integer, pointer, real and double precision versions of each +routine respectively. [str] stands for string. + + in_init[rd] (in, address(func), address(dfunc), param, dparam, + nparams, plist, nfparams) + [irdp]val = in_get[irdp] (in, param) + in_gstr (in, params, str, maxch) + in_put[irdp] (in, param, val) + in_pstr (in, param, str) + in_gkey (in, key, axis, type, varnum) + in_pkey (in, key, axis, type, varnum) + in_fit[rd] (in, nl, x, y, wts, npts, nvars, wtflag, stat) + ing_fit[rd] (in, gp, cursor, gt, nl, x, y, wts, names, npts, + nvars, len_names, wtflag, stat) + in_errors[rd] (in, nl, x, y, wts, npts, nvars, variance, + chisqr, scatter, rms, errors) + in_free[rd] (in) + + +The user supplied functions fnc and dfnc have the following calling +sequences. + + fnc (x, nvars, nparams, nparams, zfit) + dfnc (x, nvars, params, dparams, nparams, zfit, derivs) + +The addresses of the user supplied functions can be obtained with a call +to locpr as follows. + + address = locpr (fnc) + +The user definition for the INLFIT package can be found in the file +lib$pkg/inlfit.h and can be made available to user applications programs +with the statement "include <pkg/inlfit.h>". + +The permitted values for the param argument are the following. + +# Integer valued parameters (in_geti, in_puti) + +define INLFUNCTION # Fitting function +define INLDERIVATIVE # Fitting function derivatives +define INLNPARAMS # Total number of parameters +define INLNFPARAMS # Number of fitting parameters +define INLNVARS # Number of variables +define INLNPTS # Number of variables +define INLMAXITER # Max. number of iterations +define INLNREJECT # Number of rejection iterations +define INLNREJPTS # Number of rejected points +define INLUAXES # User plot function +define INLUCOLON # User colon function +define INLUFIT # User fit function +define INLOVERPLOT # Overplot next plot ? +define INLPLOTFIT # Overplot fit ? +define INLFITERROR # Error fit code +define INLGKEY # Graph key + + +# Real/double valued parameters (in_get[rd], in_put[rd]) + +define INLTOLERANCE # Tolerance of convergence +define INLLOW # Low rejection value +define INLHIGH # High rejection value +define INLGROW # Rejection growing radius + + +# Pointer valued parameters (in_getp, in_getp) + +define INLNL # NLFIT descriptor +define INLPARAM # Parameter vector +define INLDPARAM # Parameter change vector +define INLPLIST # Parameter list +define INLREJPTS # Rejected points +define INLXMIN # Minimum value for curve +define INLXMAX # Maximum value for curve +define INLSFLOAT # Floating point substructure +define INLSGAXES # Graphics substructure + + +# String valued parameters (in_gstr, in_pstr) + +define INLLABELS # standard axis labels +define INLUNITS # standard axis units +define INLFLABELS # Function labels +define INLFUNITS # Function units +define INLPLABELS # Parameter labels +define INLPUNITS # Parameter units +define INLVLABELS # Variable labels +define INLVUNITS # Variable units +define INLUSERLABELS # User plot labels +define INLUSERUNITS # User plot units +define INLHELP # Help file name +define INLPROMPT # Help prompt + + +The permitted values for the key argument are the following. + +# in_gkey, in_pkey + +define KEY_FUNCTION # Function +define KEY_FIT # Fit +define KEY_RESIDUALS # Residuals +define KEY_RATIO # Ratio +define KEY_NONLINEAR # Non-linear part +define KEY_VARIABLE # Variable (user or default) +define KEY_UAXIS # User plot function +define KEY_MIN # Min. key type +define KEY_MAX # Max. key type + +The permitted values for the axis argument are the following. + +# in_gkey, in_pkey + +define INLXAXIS # X axis +define INLYAXIS # Y axis + + +The permitted values of the weights flag argument wtflag input to +in_fit[rd] or in_gfit[rd], and the stat argument returned by in_fit[rd] +or in_gfit[rd] are defined in lib$math/nlfit.h. They can be included in +the user's application with the statement "include <math/nlfit.h>". +The values are listed below. + +# Permitted values for wtflag + +define WTS_USER # User supplied weights +define WTS_UNIFORM # Uniform weighting +define WTS_CHISQ # Chi-squared weighting +define WTS_SCATTER # Weights include computed scatter term + +# Permitted values for stat + +define DONE # Solution converged +define SINGULAR # Singular solution +define NO_DEG_FREEDOM # Too few points +define NOT_DONE # Solution did not converge. + +Note the pointer to the NLFIT structure nl is returned by the in_fit[rd] +and in_gfit[rd] routines and input to the in_errors[rd] routine. This +pointer must be freed separately with a call to nl_free when the fitting +process terminates. |