sn (version 0.33)

dsn2.plot: Plot of Bivariate Skew-normal Density Function

Description

Produces a contour plot of the density function of a bivariate skew-normal variate.

Usage

dsn2.plot(x, y, xi, Omega, alpha,  ...)

Arguments

x

vector of values of the first component.

y

vector of values of the second component.

xi

a vector of length 2 containing the location parameter.

Omega

a 2 by 2 matrix containing a covariance matrix.

alpha

a vector of length 2 containing the shape parameter.

...

additional parameters to be passed to contour.

Value

• A list containing the original input parameters plus a matrix containing the density function evaluated at the grid formed by the x and y values.

Side effects

A contour plot is produced on the graphical window.

Background

The multivariate skew-normal distribution is discussed by Azzalini and Dalla Valle (1996); the (Omega,alpha) parametrization adopted here is the one of Azzalini and Capitanio (1999).

Details

dsn2.plot makes use of function dmsn.

References

Azzalini, A. and Dalla Valle, A. (1996). The multivariate skew-normal distribution. Biometrika 83, 715--726.

Azzalini, A. and Capitanio, A. (1999). Statistical applications of the multivariate skew-normal distribution. J.Roy.Statist.Soc. B 61, 579--602.

See Also

dmsn, link{dsn2.plot}

Examples

x <- y <- seq(-5, 5, length=35)
dsn2.plot(x, y, c(-1,2), diag(c(1,2.5)), c(2,-3))