Pasture Regrowth after Grazing

Keywords: nonlinear regression, growth curve

Description

The yield of pasture regrowth was measured together with the number of days since last grazing. The measurements were done on different experimental units so it is reasonable to assume the errors independent.


	Variable		Description

	Days		Days since last grazing
	Yield		Yield of pasture

Download

Data File (tab-delimited text)

Source

Ratkowsky, D. A. (1983). Nonlinear Regression Modelling. Marcel Dekker, New York.

Huet, S., Bouvier, A., Gruet, M.-A., and Jolivet, E. (1996). Statistical Tools for Nonlinear Regression. A Practical Guide with S-PLUS Examples. Springer, New York. Example 1.1.1.

Analysis

The data are well fitted by a Weibull growth curve: Yield = a - b exp[ -exp{ c + d log(Days) }].