biv.test: Bivariate Test

In adehabitatHS: Analysis of Habitat Selection by Animals

Bivariate Test

Description

biv.plot displays a bivariate plot. biv.test displays the results of a bivariate randomisation test.

Usage

biv.plot(dfxy, br = 10, points = TRUE, density = TRUE, 
         kernel = TRUE, o.include = FALSE, pch, cex, col, h, sub, 
         side = c("top", "bottom", "none"), ...)
biv.test(dfxy, point, br = 10, points = TRUE, density = TRUE, 
         kernel = TRUE, o.include = FALSE, pch, cex, col, Pcol, h, sub, 
         side = c("top", "bottom", "none"), ...)

Arguments

dfxy	a data frame with N lines (couples of values) and two columns
br	a parameter used to define the numbers of breaks of the histograms. A larger value leads to a larger number of breaks
points	logical. Whether the points should be displayed
density	logical. Whether the kernel density estimation should be displayed for the marginal histograms
kernel	logical. Whether the kernel density estimation should be displayed for the bivariate plot
o.include	logical. If TRUE, the origin is included in the plot
pch	plotting "character", i.e., symbol to use for the points. (see ?points)
cex	character expansion for the points
col	color code or name for the points, see ?par
h	vector of bandwidths for x and y directions, used in the function kde2d of the package MASS. Defaults to normal reference bandwidth (see ?kde2d)
sub	a character string to be inserted in the plot as a title
side	if "top", the x and y scales of the grid are upside, if "bottom" they are downside, if "none" no legend
point	a vector of length 2, representing the observation to be compared with the simulated values of the randomisation test
Pcol	color code or name for the observed point
...	further arguments passed to or from other methods

Details

biv.test is used to display the results of a bivariate randomisation test. An example of use of the function is provided in the function niche.test.

The x-axis of the main window corresponds to the first column of dfxy; the y-axis corresponds to the second column. Kernel density is estimated to indicate the contours of the distribution of randomised values. The two marginal histograms correspond to the univariate tests on each axis, for which the p-values are computed with as.randtest (package ade4, one-sided tests).

Warning

biv.plot and biv.test use the function kde2d of the package MASS.

Author(s)

Mathieu Basille [e-mail]

See Also

as.randtest (package ade4)

Examples

x = rnorm(1000,2)
y = 2*x+rnorm(1000,2)
dfxy = data.frame(x, y)

biv.plot(dfxy)
biv.plot(dfxy, points=FALSE, col="lightblue", br=20)

p = c(3, 4)
biv.test(dfxy, p)
biv.test(dfxy, p, points=FALSE, Pcol="darkred", col="lightblue", br=20)

adehabitatHS documentation built on Sept. 11, 2024, 7:38 p.m.