plot question

hi all:
 
xlim and ylim are used to define the interval limits of a plot. I'm interested in the scale of values between this limits.
 
suppose xlim=c(0,10)
we can have e.g.
0  5  10
0  2  4  6  8  10
0  1  2  3  4  5  6  7  8  9  10
 
which is the parameter that allows me to modify this?
 
thanks in advance
alexandre