Create intervals based on condition for annotate ggplot2

Question

I have a vector called ranks with values from -6 to 6 and I want to create intervals of number of values based on value intervals such as (2, Inf) [2, 1.25) etc that include the number of values in that interval, plus the ones in the previous interval. In other words, for interval of values (2, Inf) I want to obtain the number of values in this interval plus those in the previous one.

To do this I used a very primitive approach:

   xmin <- c(0, sum(ranks>2),
            sum(ranks>2) + sum(ranks>1.25),
            sum(ranks>2) + sum(ranks>1.25) + sum(ranks>0.75),
            sum(ranks>2) + sum(ranks>1.25) + sum(ranks>0.5) + sum(ranks>0.25)) 
   xmax <- c(c(sum(ranks>2),
            sum(ranks>2) + sum(ranks>1.25),
            sum(ranks>2) + sum(ranks>1.25) + sum(ranks>0.75),
            sum(ranks>2) + sum(ranks>1.25) + sum(ranks>0.5) + sum(ranks>0.25))-1,
            length(ranks))

Where xmin is the start of each interval and xmax the end of each interval. But I believe there is a much better straightforward way to do it.

Overall I'd like to find the values separating in this intervals: +Inf, 2, 1, 0.5, 0, -0.5, -1, -2, -Inf

PS: I'll be using these to annotate x axis in ggplot2 as shown below (see the color scale from red to blue, those are rectangles with specific x and y delimiters)

Answer 1

Try this:

c(1, 1, 2, 3, 2, 1, 4, 2, 5, 6, 2, 5, 3) %>% 
  cut(c(0, 2, 4, 6)) %>% 
  table() %>%
  cumsum()

(0,2] (2,4] (4,6] 
    7    10    13 

UPD: just noticed - you're arranging your intervals in reverse. I think the easiest way would be to convert the table to numeric and rev erse it before cumsum ing

Answer 2

I might still have misunderstood, but in the end it's just a matter of counting how many genes are in each interval, correct?

Basically you're re-inventing a stacked bar.

library(ggplot2)

# random data
set.seed(1)
rank <- sample(-6:6, 11000, replace = T)
# vector of your cuts
my_cuts <- c(-Inf, -2, -1, -0.5, 0, 0.5, 1, 2, Inf)
## make a data frame and cut the ranks
genes <-  data.frame(rank)
genes$cuts <- cut(genes$rank, my_cuts)

## just use geom_bar
ggplot(genes) +
  geom_bar(aes(y = 1, fill = cuts)) +
  ## now you can simply use one of the scale functions
  scale_fill_brewer(palette =  "Reds")

^{Created on 2022-05-31 by the reprex package (v2.0.1)}