[R] Plot point patterns

[Vanesa Maria Santos Sanchez]

Hello!
I want to plot a multitype point pattern called "new" in package 
spatstat. When I write plot(new) in the graphic window I can see a 
strech rectangle with a point inside, not the point pattern.If I 
write plot(new$x,new$y) the point pattern is plot ok.The problem 
is that I want do the density plots, quadrat count, etc and in 
these cases I can´t write density(new$x,new$y), I must do it only 
whith the name of the point pattern.
What is the problem?
Thanks.