Para: Curve parameters of HOF models
Description
One of the advantages using a restricted set of models, is the possibility to derive common shape parameters from the different model types. Function Para calculates a set of parameters (see below) from HOF models.Usage
## S3 method for class 'HOF':
Para(resp, model, newdata = NULL, ...)
## S3 method for class 'HOF.list':
Para(resp, ...)
Value
speciesName or abbreviat of the species.abund sumAbundance sum, i.e. sum of all response values divided by M.rangeRange of x values.modelModel type, if not specified the result of pick.model.paraModel parameters (a to d).MMaximum response value, specified in the HOF function call.miniLocation of the minimum, i.e. the gradient value, where the response is lowest.pessLowest estimated response value.topHighest estimated response value.optLocation of the optimum, i.e. the gradient value, where the species response is highest. NA for model I and an optimum interval for model type III.expectExpectancy value, i.e. average x value under the model curve).max slopeHighest slope, i.e. maximum of the first derivation of the curve.centralBorderFollowing Heegard, the central borders are calculated as the gradient values, where the response reaches "exp(-1/2)" of the top.outerBorderFollowing Heegard, the outer borders of the species niche are calculated as the gradient values, where the response reaches exp(-2) of the top.raw meanAverage of measured x values.References
Heegard, E. (2002) The outer border and central border for species-environmental relationships estimated by non-parametric generalised additive models. Ecological Modelling, 157, 131-139.
Damgaard, C. (2006) Modelling ecological presence-absence data along an environmental gradient: threshold levels of the environment. Environ Ecol Stat 13:229-236.