28.1.55 ExpDecay3

Function

y=y_0+A_1e^{-(x-x_0)/t_1}+A_2e^{-(x-x_0)/t_2}+A_3e^{-(x-x_0)/t_3}

Brief Description

Three-phase exponential decay function with time offset, x0 should be fixed.

Sample Curve

CFF Image168.jpg

Parameters

Number: 8

Names: y0, x0, A1, t1, A2, t2, A3, t3

Meanings: y0 = offset, x0 = center, A1 = amplitude, t1 = time constant, A2 = amplitude, t2 = time constant, A3 = amplitude, t3 = time constant

Lower Bounds: none

Upper Bounds: none

Note: different initial parameters are used for t1, t2 and t3 so as to make sure t3 > t2 > t1 in the fitting results.

Script Access

nlf_expdecay3(x,y0,x0,A1,t1,A2,t2,A3,t3)

Function File

FITFUNC\EXPDECY3.FDF

Category

Exponential