Find overlapping ranges by factor level using R

Question

I need to find overlapping ranges within a single data set but need to find them for each ID or factor level. Any assistance would be appreciated!

    library(dplyr)

df_foo = read.table(
  textConnection("Class    Min  Max
A    500  630
A    100  200
B    100  200
A    210  310
A    200  210
B    210  310
A    510  530
B    200  210
A    705  800
B    500  630
B    510  530
B    705  800"), header = TRUE
)

c = outer(df_foo$Max, df_foo$Min, ">")
d = outer(df_foo$Min, df_foo$Max, "<")

df_foo %>% 
  mutate(Overlap = apply(c & d, 1, sum) > 1 
  )

The result I am getting is as follows:

   Class Min Max Overlap
1      A 500 630    TRUE
2      A 100 200    TRUE
3      B 100 200    TRUE
4      A 210 310    TRUE
5      A 200 210    TRUE
6      B 210 310    TRUE
7      A 510 530    TRUE
8      B 200 210    TRUE
9      A 705 800    TRUE
10     B 500 630    TRUE
11     B 510 530    TRUE
12     B 705 800    TRUE

But I want to find the overlaps between each level of A and B like this:

   Class Min Max Overlap
1      A 500 630    TRUE
2      A 100 200    FALSE
3      B 100 200    FALSE
4      A 210 310    FALSE
5      A 200 210    FALSE
6      B 210 310    FALSE
7      A 510 530    TRUE
8      B 200 210    FALSE
9      A 705 800    FALSE
10     B 500 630    TRUE
11     B 510 530    TRUE
12     B 705 800    FALSE

Answer 1

I have the answer in data.table, the translation into dplyr should be straigtworfard. The idea is to create a vector of the previous cumulated maximum , per class :

df_foo <- setDT(df_foo)
df_foo[, shiftedmaxmax := c(NA,cummax(Max)[1:(.N-1)]),by = Class  ]


    Class Min Max shiftedmaxmax
 1:     A 100 200            NA
 2:     A 200 210           200
 3:     A 210 310           210
 4:     A 500 630           310
 5:     A 510 530           630
 6:     A 705 800           630
 7:     B 100 200            NA
 8:     B 200 210           200
 9:     B 210 310           210
10:     B 500 630           310
11:     B 510 530           630
12:     B 705 800           630

And to compare the minimum with the previous maximum of Maximum (so if it is inferior to this value, the current line is in the range of one previous line)

df_foo[,superposed := Min < shiftedmaxmax]

    Class Min Max shiftedmaxmax superposed
 1:     A 100 200            NA         NA
 2:     A 200 210           200      FALSE
 3:     A 210 310           210      FALSE
 4:     A 500 630           310      FALSE
 5:     A 510 530           630       TRUE
 6:     A 705 800           630      FALSE
 7:     B 100 200            NA         NA
 8:     B 200 210           200      FALSE
 9:     B 210 310           210      FALSE
10:     B 500 630           310      FALSE
11:     B 510 530           630       TRUE
12:     B 705 800           630      FALSE

The first superposed is missing, and you can get it this way:

df_foo[,superposedsource :=  Max %in% shiftedmaxmax[superposed],by = Class]
df_foo[,superposedtot := ifelse((superposed | superposedsource) &,T,F)]

    Class Min Max shiftedmaxmax superposed superposedsource superposedtot
 1:     A 100 200            NA         NA            FALSE            NA
 2:     A 200 210           200      FALSE            FALSE         FALSE
 3:     A 210 310           210      FALSE            FALSE         FALSE
 4:     A 500 630           310      FALSE             TRUE          TRUE
 5:     A 510 530           630       TRUE            FALSE          TRUE
 6:     A 705 800           630      FALSE            FALSE         FALSE
 7:     B 100 200            NA         NA            FALSE            NA
 8:     B 200 210           200      FALSE            FALSE         FALSE
 9:     B 210 310           210      FALSE            FALSE         FALSE
10:     B 500 630           310      FALSE             TRUE          TRUE
11:     B 510 530           630       TRUE            FALSE          TRUE
12:     B 705 800           630      FALSE            FALSE         FALSE

Answer 2

An other data.table approach.
The order of the sample data / ranges is irrelevant in this answer... foverlaps() does all the hard work for you.

sample data

library( data.table )
dt <- as.data.table( df_foo )

code

#set key for the data.table
setkey(dt, Min, Max)
#perform overlap join, keep only joined ranges where the class is the same, and Min and Max are not the same.
result <- foverlaps( dt, dt )[ Class == i.Class & !(Min == i.Min | Max == i.Max | Min == i.Max | Max == i.Min), ]
#create a logical vector (i.e. Overlap) by checking if the (pasted) combination of
#Class, Min and Max exists in both 'dt' and 'result'
dt[ , Overlap := paste0( Class, Min, Max ) %in% paste0( result$Class, result$Min, result$Max) ][]

#     Class Min Max Overlap
#  1:     A 100 200   FALSE
#  2:     B 100 200   FALSE
#  3:     A 200 210   FALSE
#  4:     B 200 210   FALSE
#  5:     A 210 310   FALSE
#  6:     B 210 310   FALSE
#  7:     A 500 630    TRUE
#  8:     B 500 630    TRUE
#  9:     A 510 530    TRUE
# 10:     B 510 530    TRUE
# 11:     A 705 800   FALSE
# 12:     B 705 800   FALSE