[R] Help with filled.contour()

[Michael Kubovy]

The following plot is a first approximation to what I need:

***********************************
mu1 <- 0
mu2 <- 5
s <- 1
x <- seq(-2.5, 7.5, length = 41)
y <- seq(-2.5, 2.5, length = 41)
f <- function(x,y){
term1 <- 1/(2*pi*sqrt(s*s))
term2 <- -1/2
term3 <- (x - mu1)^2/s
term4 <- (y - mu1)^2/s
term5 <- (x - mu2)^2/s
term1*(.5 * exp(term2*(term3 + term4)) + .5 * exp(term2*(term5 +  
term4)))
}
z <- outer(x, y, f)
persp(x, y, z)
require(grDevices)
filled.contour(x, y, z, axes = F, frame.plot = F, asp = 1,
     col = palette(gray(seq(0, 0.9, len = 25))), nlevels = 25)
***********************************
It has four drawbacks. I would like:
(1) to remove the white grid;
(2) to remove the white contours;
(3) its appearance to be smooth;
(4) to remove the key.
_____________________________
Professor Michael Kubovy
University of Virginia
Department of Psychology
USPS:     P.O.Box 400400    Charlottesville, VA 22904-4400
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         McCormick Road    Charlottesville, VA 22903
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WWW:    http://www.people.virginia.edu/~mk9y/