Hi,
It is better to show the example data using ?dput(). Here, it is not clear
whether the columns are character columns or lists.
##If it is the latter case
dat1 <- data.frame(V1=I(list(1:3, c(1,2,4), c(2,3,4,5))), V2= I(list(c(3,6,5),
c(7,10,9), 2:5)))
dat1$V3 <- mapply(`c`,mapply(`-`, lapply(dat1$V2, `[`,-1),
lapply(dat1$V1,head,-1)), lapply(dat1$V1,tail,1))
dat1
# V1 V2 V3
#1 1, 2, 3 3, 6, 5 5, 3, 3
#2 1, 2, 4 7, 10, 9 9, 7, 4
#3 2, 3, 4, 5 2, 3, 4, 5 1, 1, 1, 5
##If the columns are character vectors.
dat2 <- structure(list(V1 = c("1,2,3", "1,2,4", "2,3,4,5"), V2 = c("3,6,5",
"7,10,9", "2,3,4,5")), .Names = c("V1", "V2"), row.names = c(NA,
-3L), class = "data.frame")
lst1 <- sapply(dat2, function(x) lapply(strsplit(x, split=","),as.numeric))
dat2$V3 <- unlist(lapply(mapply(`c`,mapply(`-`, lapply(lst1[,2],`[`, -1),
lapply(lst1[,1], head,-1)), lapply(lst1[,1], tail,1)), paste, collapse=","))
dat2
# V1 V2 V3
#1 1,2,3 3,6,5 5,3,3
#2 1,2,4 7,10,9 9,7,4
#3 2,3,4,5 2,3,4,5 1,1,1,5
A.K.
Hi,
I have a quick question in R. I have dataframe with two columns with multiple
values separated by comma.
Example:
V1 V2
1 1, 2, 3 3, 6, 5
2 1, 2, 4 7, 10, 9
3 2, 3, 4, 5 2, 3, 4, 5
I want to calculate the difference between both the column.
Expected results (suppose results are stored in V3) - it is basically
subtracting (n-th) value of the column1 from (n-th + 1) value of column2.
V3
1 6-1, 5-2, 3
2 10-1, 9-2, 4
3 3-2, 4-3, 5-4, 5
which gives (Last value doesn't matter)
V3
1 5, 3, 3
2 9, 7, 4
3 1, 1, 1, 5
Would greatly appreciate if anyone can suggest how can I proceed?
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