I have a data frame, I want to get the matrix with row 1 paste with row 2, row 3 paste with row 4, if the data frame have odd row, leave the last row the same, instead of paste row, paste column 1 and column2, column 3 and column 4, Matrix will be:
data <- data.frame(name = c(1:4), plate=c("A","B","C","D"), value1=c(4:7), value2 = c(100, 200, 300, 400))
data
name plate value1 value2
1 A 4 100
2 B 5 200
3 C 6 300
4 D 7 400
The result for matrix paste by rows:
name plate value1 value2
1-2 A-B 4-5 100-200
3-4 C-D 6-7 300-400
The result for matrix paste by columns:
name-plate value1-value2
1-A 4-100
2-B 5-200
3-C 6-300
4-D 7-400
I know how to paste all of them together, but I don't know how to do separately
> apply( data[,1:4] , 1, paste , collapse = "-" )
[1] "1-A-4-100" "2-B-5-200" "3-C-6-300" "4-D-7-400"
Appreciate for your helps.
答案 0 :(得分:3)
You can probably start from something like the following, where you extract the odd (data[c(T, F), ])
and even (data[c(F, T), ])
rows separately and use the mapply
function to loop through them simultaneously and paste them together. Similar logic goes with the columns.
mapply(paste, sep = "-", data[c(T,F),], data[c(F,T),])
# - <NA> <NA> <NA>
# [1,] "1-2" "A-B" "4-5" "100-200"
# [2,] "3-4" "C-D" "6-7" "300-400"
mapply(paste, sep = "-", dat[,c(T,F)], dat[,c(F,T)])
# - <NA>
# [1,] "1-A" "4-100"
# [2,] "2-B" "5-200"
# [3,] "3-C" "6-300"
If you need to set up the column names at the same time:
setNames(as.data.frame(mapply(paste, sep = "-", data[c(T,F),], data[c(F,T),])),
names(data))
# name plate value1 value2
# 1 1-2 A-B 4-5 100-200
# 2 3-4 C-D 6-7 300-400
setNames(as.data.frame(mapply(paste, sep = "-", data[,c(T,F)], data[,c(F,T)])),
paste(names(data)[c(T,F)], names(data)[c(F,T)], sep = "-"))
# name-plate value1-value2
# 1 1-A 4-100
# 2 2-B 5-200
# 3 3-C 6-300
# 4 4-D 7-400
Note: This doesn't take care of the odd row or column cases, so you will need some effort to handle that.
答案 1 :(得分:1)
我们可以使用lapply
as.data.frame(t(sapply(seq(1, nrow(data), by = 2), function(i)
apply(data[i:(i+1),], 2, paste, collapse="-"))))
# name plate value1 value2
#1 1-2 A-B 4-5 100-200
#2 3-4 C-D 6-7 300-400
setNames(as.data.frame(sapply(seq(1, nrow(data), by = 2), function(i)
apply(data[,i:(i+1)], 1, paste, collapse="-"))), c("name-plate", "value1-value2"))
# name-plate value1-value2
#1 1-A 4-100
#2 2-B 5-200
#3 3-C 6-300
#4 4-D 7-400
答案 2 :(得分:0)
另一种方法是使用tidyr包中的unite函数。
library(tidyr)
data <- data.frame(name = c(1:4),
plate=c("A","B","C","D"),
value1=c(4:7),
value2 = c(100, 200, 300, 400))
data %>%
unite("name-plate", name, plate, remove = T, sep = "-") %>%
unite("value1-value2", value1, value2, remove = T, sep = "-")
# outputs the following data.frame
name-plate value1-value2
1 1-A 4-100
2 2-B 5-200
3 3-C 6-300
4 4-D 7-400