How to change discrete ratio data into ordinal data in R?

Question

Here is an example:

   height
1  1.5
2  1.3 
3  1.9 
4  1.5
5  1.6 

There are 1000 of them with height ranging from 0 to 1.9. And I want to cut them into 3 levels: low, medium and high. Then they are ordinal data.

result should look like this:

   height
1  medium
2  low
3  high
4  medium
5  medium

And the summary should look like:

        height
low:    203
medium: 723
high:   74

I tried to use the loop but then "low, medium and high" are characters, not levels. Here is how I did the low part:

height_cuts = c(1.5,1.9)
for(i in 1:nrow(health.sample)){
  if(is.na(health.sample$height[i])==FALSE){
    if(health.sample$height[i] < height_cuts[1]){
      health.sample$height[i] = low_h
    }
  }
}

Answer 1

cut(height, quantile(height, prob=c(203, 723, 74)/1000 ), labels=c("low", "medium", "high") )

Answer 2

cut will, conveniently enough, cut your data.

# cut needs all endpoints explicitly specified, including outside bounds
height_cuts <- c(-Inf, 1.5, 1.9, Inf)

hcut <- cut(height, height_cuts, labels=c("low", "medium", "high"))

ETA: this will make intervals based on <=1.5, <=1.9. If you want the intervals to be <1.5, <1.9, specify right=FALSE:

hcut <- cut(height, height_cuts, right=FALSE, ...)