28.1.30 DoubleBoltzmann

Function

y=y_0+A\left[\frac{p}{1+e^{\frac{x-x_{01}}{k_1}}}+\frac{1-p}{1+e^{\frac{x-x_{02}}{k_2}}}\right]

Brief Description

Double Boltzmann Function, sum of two Boltzmann functions.

Sample Curve

DoubleBoltzmann.png

Parameters

Number: 7

Names: y0, A, frac, x01, x02, k1, k2

Meanings: y0 = Offset, A = Span, frac = Fraction, x01 = Center, x02 = Center, k1 = Slope factor, k2 = Slope factor

Lower Bounds: frac > 0

Upper Bounds: frac < 1

Derived Parameters

Bottom asymptote:

A1=A*frac

Top asymptote:

A2=A*(1-frac)

The concentration at half response:

EC50_1=exp(x01)

EC50_2=exp(x02)

Script Access

nlf_DoubleBoltzmann(x,y0,A,frac,x01,x02,k1,k2)

Function File

FITFUNC\DOUBLEBOLTZMANN.FDF

Category

Growth/Sigmoidal