zwietering_gamma {biogrowth}

Zwietering gamma model

Description

Gamma model as defined by Zwietering et al. (1992). To avoid unreasonable predictions, it has been modified setting gamma=0 for values of x outside (xmin, xopt)

Usage

zwietering_gamma(x, xmin, xopt, n)

Arguments

x

Value of the environmental factor.

xmin

Minimum value of the environmental factor for growth.

xopt

Maximum value for growth

n

Exponent of the secondary model

Value

The corresponding gamma factor.