splitting a data into several parts - r

Question

My data is below which I want to split it based on IDs into several parts
df1<- structure(list(Ids1 = 1:7, string1 = structure(c(3L, 2L, 4L,
1L, 1L, 1L, 1L), .Label = c("gdyijq,udyhfs,gqdtr", "hdydg", "hishsgd,gugddf",
"ydis"), class = "factor"), Ids2 = c(1L, 3L, 4L, 9L, 10L, NA,
NA), string2 = structure(c(4L, 6L, 2L, 3L, 5L, 1L, 1L), .Label = c("",
"gdyijq,udyhfs", "gqdtr", "hishsgd,gugddf", "nlrshf", "ydis"), class = "factor")), .Names = c("Ids1",
"string1", "Ids2", "string2"), class = "data.frame", row.names = c(NA,
-7L))
The first I want to make df.1 when I keep only those that have similar Ids and count how many of string1 is similar to string2 (they are separated by a comma).
Ids1 string1 ids2 string2 Similar
1 hishsgd,gugddf 1 hishsgd,gugddf 2
3 ydis 3 ydis 1
4 gdyijq,udyhfs,gqdtr 4 gdyijq,udyhfs 2
I do this
df.1 <- df1[which(df1$Ids1 == df1$Ids2), ]
which only gives me the first row and nothing else
Then I want to have those that there are only ids 1 which dont exist in ids2
Ids1 string1
2 hdydg
5 gdyijq,udyhfs,gqdtr
6 gdyijq,udyhfs,gqdtr
7 gdyijq,udyhfs,gqdtr
I do this but also does not work
df.2<- df1[which(df1$Ids1 != df1$Ids2), ]
and the last I want to keep those that are only in ids2 and not ids1
Ids1 string1
9 gqdtr
10 nlrshf
which I do this but also does not work
df.3<- df1[which(df1$Ids2 != df1$Ids1), ]

Answer 1

Here is one solution I could come up with based on joins using dplyr package:
library(dplyr)
df.1 <- inner_join(select(df1, Ids1, string1), select(df1, Ids2, string2), by = c('Ids1' = 'Ids2'))
df.1$Similar <- apply(df.1[, -1], 1, function(x) sum(unlist(strsplit(x[1], ',')) %in% unlist(strsplit(x[2], ','))))
df.2 <- anti_join(select(df1, Ids1, string1), select(df1, Ids2, string2), by = c('Ids1' = 'Ids2'))
df.3 <- anti_join(select(df1, Ids2, string2), select(df1, Ids1, string1), by = c('Ids2' = 'Ids1'))
df.3 <- df.3[complete.cases(df.3), ]
You can also do something different for df.2 and df.3 as follows:
df.2 <- df1[!df1$Ids1 %in% df1$Ids2, c('Ids1', 'string1')]
df.3 <- df1[!df1$Ids2 %in% df1$Ids1, c('Ids2', 'string2')]
df.3 <- df.3[complete.cases(df.3), ]