Predefined Fit Curves Equations

All predefined Fit Curves are listed in this table. You also can specify custom fit equation. Unlike custom fit equations these curves can be adjusted with mouse on Fit Plot.

Name	Formula	Parameters Meaning	Additional Properties
Line	a --- linear b --- constant
Parabola	a --- quadratic b --- linear c --- constant	Vertex:
Spline	Natural cubic spline, on each i-th piece:	xN --- anchor point x-coordinates yN --- anchor point y-coordinates
Gaussian	a --- amplitude dx --- half width at half maximum (HWHM) x0 --- maximum position	Area (integral): Standard deviation:
Gaussian-A (area-normalized)	a --- area (integral) dx --- half width at half maximum (HWHM) x0 --- maximum position	Amplitude: Standard deviation:
Lorentzian	a --- amplitude dx --- half width at half maximum (HWHM) x0 --- maximum position	Area (integral):
Lorentzian-A (area-normalized)	a --- area (integral) dx --- half width at half maximum (HWHM) x0 --- maximum position	Amplitude:
Gauss Derivative	Parameters are the same as for original Gaussian: a --- amplitude dx --- half width at half maximum (HWHM) x0 --- center position	Area of original Gaussian (second integral): Standard deviation: Peak-to-peak horizontal: Peak-to-peak vertical:
Lorentz Derivative	Parameters are the same as for original Lorentzian: a --- amplitude dx --- half width at half maximum (HWHM) x0 --- center position	Area of original Lorentzian (second integral): Peak-to-peak horizontal: Peak-to-peak vertical:

See Also

Nonlinear Curve Fitting: Fit Plot

Using Spline for Baseline Subtraction

Guessing Peaks