GaussPara: Finds Gaussian Parameters of a Response Model.

In jarioksa/gravy: Gradient Analysis of Vegetation

Description

GaussPara is a generci function to find Gaussian parameters in any response function. In Gaussian function, these will be the real Gaussian paramters, in other models similar parameters for the height at optimum ("top"), location of the optimum ("opt") and the width of the response at height exp(-0.5)*top. For unsymmetric responses, parameter tol gives the width to the left and tol.right the width to the right of opt.

Usage

GaussPara(resp, ...)

Arguments

resp	Response function for a single species or a list of responses from a data frame method.
...	Other parameters. See individual response models for possible other paraemters.

Details

See individual response functions for more details.

Value

Returns an object with (at least) items top for the height at the optimum, opt for the location of the optimum), tol for the width to the left of the optimum, tol.right width to the right of the optimum or text symmetric for symmetric responses. Individual response functions may add some items to these.

Note

Currently implemented only for HOF.

Author(s)

Jari Oksanen

References

Lawesson, J.E. & Oksanen, J. (2002) Niche characteristics of Danish woody species as derived from coenoclines. Journal of Vegetation Science 13: 279-290. (For HOF models.)

See Also

HOF is the only implementation. If the parameters cannot be found in closed form, optimize is used for opt and uniroot for tol and tol.right.

Examples

data(mtf01)
data(mtf.alt)
attach(mtf.alt)
mods <- HOF(mtf01, Altitude, 1)
GaussPara(mods)

jarioksa/gravy documentation built on May 18, 2019, 3:47 p.m.