R help - May 2007 - 3d graph question

Hi, this is simple,

I've generated a bivariate normal distribution with a known correlation. 
  I want to plot the density function with p(y,x) on the vertical axis 
and x, and y on the horizontal axes.  How is that done? Thanks in advance!


library(MASS)
mu <- c(0,1) # mean vector
sigma <- matrix(c(1,.8,.8,1), ncol=2)
tmp <- mvrnorm(1000, mu, sigma)
cor(tmp)
plot(tmp,ylab='achievement', xlab='ses') # plot data

-- 
==========================================================================David
Kaplan, Ph.D.
Professor
Department of Educational Psychology
University of Wisconsin - Madison
Educational Sciences, Room, 1061
1025 W. Johnson Street
Madison, WI 53706

email: dkaplan at education.wisc.edu
homepage: http://www.education.wisc.edu/edpsych/facstaff/kaplan/kaplan.htm
Phone: 608-262-0836

On 5/17/2007 3:42 PM, David Kaplan wrote:
> Hi, this is simple,
> 
> I've generated a bivariate normal distribution with a known
correlation.
>   I want to plot the density function with p(y,x) on the vertical axis 
> and x, and y on the horizontal axes.  How is that done? Thanks in advance!
> 
> 
> library(MASS)
> mu <- c(0,1) # mean vector
> sigma <- matrix(c(1,.8,.8,1), ncol=2)
> tmp <- mvrnorm(1000, mu, sigma)
> cor(tmp)
> plot(tmp,ylab='achievement', xlab='ses') # plot data
You need to calculate the density for each element of an array whose 
rows correspond to x values, and columns to y values.  Then persp or 
contour can plot it (or persp3d in the rgl package).

Duncan Murdoch