比较r中的两个表

Question

I have a table with reference positions, like x is the start and y is the end.

|---------------------|------------------|
|           x         |        y         |
|---------------------|------------------|
|          10         |         35       |
|---------------------|------------------|
|          58         |         89       |
|---------------------|------------------|

Then I have another table with single positions and my goal is to check if any of the positions in this second table are in the first table, considering that the positions in this second table can be in between the col1 and col2.

|---------------------|
|          12         |     
|---------------------|
|          27         |       
|---------------------|
|          65         |
|---------------------|

How can I check this, since I can't use any of the joins from dplyr , or even the unique .

Answer 1

We can use foverlaps from data.table

library(data.table)
df1 <- data.frame(x = c(10, 58), y = c(35, 89))
df2 <- data.frame(x= c(12, 27, 65), y = c(12, 27, 65))
setDT(df1, key = c('x', 'y'))
setDT(df2, key = c('x', 'y'))
foverlaps(df2, df1, type = "within", which = TRUE)$yid 
#[1] 1 1 2

Answer 2

Version 1.9.8 of data.table (on CRAN 25 Nov 2016) introduced non-equi joins which can be used instead of foverlaps() :

setDT(df1)[setDT(df2), on = .(x <= z, y >= z), which = TRUE]

 [1] 1 1 2 NA 

Note that the second table differs from OP's data as a fourth row has been added which doesn't match any of the intervals.

Data

df1 <- data.frame(x = c(10, 58), y = c(35, 89))
df2 <- data.frame(z = c(12, 27, 65, 90))