values in between

To start with, pardon my mistake regarding  "two vectors"

Yes I want all values (to two decimal digits if I can) between each of 
the values given in the vector.
meaning I'm really try to do something like this:
y<- c(0.4 : 0.0 : 0.2 : -0.2 : 0.6 : 0.2 : 0.0 : 0.0 : 0.4 : 0.4 : 0.2)
which of course does not work. (But on this point, something like m<- 
c(0.2:-0.6) doesn't work either.

Hi Eric,

Okay, what you probably want is:

seq(0.4,0.0,by=0.01*sign(0.0-0.4))
...

This can be worked into the function that I posted, but it's getting a 
bit tricky to make it general. What you want to do is to "walk" through 
the values creating a sequence between each one with the above call.

in.betweens<-function(x,increment) {
  lenx<-length(x)
  newx<-x[1]
  for(i in 1:(lenx-1))
   newx<-c(newx,seq(x[i],x[i+1],by=increment*sign(x[i+1]-x[i]))[-1])
  return(zapsmall(newx))
}

Jim