cheddar (version 0.1-639)

NvMConvexHull: NvMConvexHull

Description

Compute the convex hull around log-transformed $N$ versus $M$ data.

Usage

NvMConvexHull(community)

Value

A list containing the values

nodes

The names of the nodes that make up the convex hull.

points

A matrix containing columns `x' and `y' that contain the coordinates of the points that make up the convex hull.

area

The area within the convex hull.

Arguments

community

an object of class Community.

Author

Lawrence Hudson

Details

Returns the points and area of the minimum convex hull (a polygon in log10-transformed numerical abundance versus log10-transformed body mass space) that bounds all the species within the community.

References

Leaper, R. and Raffaelli, D. (1999) Defining the abundance body-size constraint space: data from a real food web. Ecology Letters 2, 3, 191--199.

See Also

Community, PlotNvM, chull

Examples

data(TL84)

# Compute convex hull
convex.hull <- NvMConvexHull(TL84)

# The nodes that form the hull
convex.hull$nodes

# The area of the hull
convex.hull$area

# Plot the hull in red around the nodes
PlotNvM(TL84)
polygon(convex.hull$points, lwd=2, border='red')