dsn2.plot {sn} | R Documentation |
Produces a contour plot of the density function of a bivariate skew-normal variate.
dsn2.plot(x, y, xi, Omega, alpha, ...) dsn2.plot(x, y, dp=, ...)
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. |
dp |
a list with components named xi, Omega, alpha , containing
quantities as described above. If this parameter is set, then the
individual parameters must not be.
|
... |
additional parameters to be passed to contour .
|
The density function is evalutate at the grid of points whose
coordinates are given by vectors x
and y
.
The actual computation is done by the function dmsn
.
A contour level plot is produced on the graphical window.
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.
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).
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.
x <- y <- seq(-5, 5, length=35) dsn2.plot(x, y, c(-1,2), diag(c(1,2.5)), c(2,-3))