cheddar (version 0.1-626)

NvMConvexHull: NvMConvexHull

Description

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

Usage

NvMConvexHull(community)

Arguments

community

an object of class 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.

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')