Class NLFitPreset

Calculates preset function value in a single point with given parameters.

Parameters:

• x - The point to compute value at. (float)
• params - Preset parameter values. (const-gdouble*)
• fres - Set to True if succeeds, False on failure. (gboolean*)

Returns:

The function value. (float)

Gets function formula of preset (with Pango markup).

Returns:

The preset function formula. (string)

Return the number of parameters of preset.

Returns:

The number of function parameters. (int)

Gets the name of a fitting parameter of a fitter preset.

The name may contain Pango markup.

Parameters:

• param - A parameter number. (int)

Returns:

The name of parameter @param. (string)

Derives the SI unit of a fitting parameter from the units of abscissa and ordinate.

Parameters:

• param - A parameter number. (int)
• siunit_x - SI unit of abscissa. (SIUnit)
• siunit_y - SI unit of ordinate. (SIUnit)

Returns:

A newly created SIUnit with the units of the parameter @param. If the units of @param are not representable as SIUnit, the result is unitless (i.e. it will be presented as a mere number). (SIUnit)

Performs a nonlinear fit with a preset.

See gwy_math_nlfit_fit_full() for details.

Parameters:

• fitter - A Marquardt-Levenberg nonlinear fitter already initialized for preset's function, or None. (MathNLFit*)
• n_dat - The number of data points (number of items in x and y). (int)
• x - Abscissa points. (const-gdouble*)
• y - Ordinate points. (const-gdouble*)
• params - Initial parameter estimate (the number of parameters depends on the fitted preset and it can be obtained with gwy_nlfit_preset_get_nparams()). (gdouble*)
• err - Array to store parameter errros to, may be None. (gdouble*)
• fixed_param - Which parameters should be treated as fixed (set corresponding element to True for them). May be None if all parameters are variable. (const-gboolean*)

Returns:

Either fitter itself, or a newly created fitter if it was None. (MathNLFit*)