问题
Please help me with the following matter
I have a wide data frame that I need to reshape.
This is the df I have
mydf <- data.frame(date=1983:1985,January=c(5,7,8),February=c(12,18,19))
mydf
this is the output I need
output <- data.frame(date=rep(c(1983,1984,1985),each=2),Month=rep(c("January","February"),3),Value=c(5,12,7,18,8,19))
output
回答1:
We can use pivot_longer
library(tidyr)
library(dplyr)
mydf %>%
pivot_longer(cols = -date, names_to = 'Month', values_to = 'Value')
# date Month Value
#1 1983 January 5
#2 1983 February 12
#3 1984 January 7
#4 1984 February 18
#5 1985 January 8
#6 1985 February 19
回答2:
Using melt from reshape2:
reshape2::melt(mydf, id.vars = "date", measure.vars = c("January", "February"), variable.name = "Month", value.name = "Value")
# date Month Value
#1 1983 January 5
#2 1984 January 7
#3 1985 January 8
#4 1983 February 12
#5 1984 February 18
#6 1985 February 19
来源：https://stackoverflow.com/questions/59847219/reshaping-the-data-from-wide-to-long