[R] Help with filled.contour()

[Dieter Menne]

Michael Kubovy <kubovy <at> virginia.edu> writes:

> 
> The following plot is a first approximation to what I need:
.. see below 

> ***********************************
> 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.


In partial fulfillment of your requirements, increasing the levels gives a nice
smooth plot.

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 = 500))), nlevels = 500)

I thought that lattice would be more flexible, and getting rid of the keys was
easy, only I could not get the smooth plot. Deepayan, are we missing something?

library(lattice)
dt <- expand.grid(x=x,y=y)
dt$z <- apply(dt, 1,function(xy)  f(xy[1],xy[2]))
col.regions = palette(gray(seq(0, 0.9, len = 500)))
contourplot(z~x*y,data=dt,cuts=20,col.regions=col.regions,colorkey=FALSE,
  contour=TRUE,region=TRUE)


Dieter