问题
I want to recode some numeric values into different numeric values and have had a go using the following code:
survey$KY27PHYc <- revalue(survey$KY27PHY1, c(5=3, 4=2,3=2,2=1,1=1))
I get the following error:
## Error: unexpected '=' in "survey$KY27PHYc <- revalue(survey$KY27PHY1, c(5="
Where am I going wrong?
回答1:
This function does not work on numeric vector. If you want to use it, you can do as follows:
x <- 1:10 # your numeric vector
as.numeric(revalue(as.character(x), c("2" = "33", "4" = "88")))
# [1] 1 33 3 88 5 6 7 8 9 10
回答2:
We can recode numeric values by using recode or case_when on dplyr 0.7.0.
library(dplyr)
packageVersion("dplyr")
# [1] ‘0.7.0’
x <- 1:10
# With recode function using backquotes as arguments
dplyr::recode(x, `2` = 20L, `4` = 40L)
# [1] 1 20 3 40 5 6 7 8 9 10
# Note: it is necessary to add "L" a numerical value.
dplyr::recode(x, `2` = 20, `4` = 40)
# [1] NA 20 NA 40 NA NA NA NA NA NA
# Warning message:
# Unreplaced values treated as NA as .x is not compatible. Please specify replacements exhaustively or supply .default
# With recode function using characters as arguments
as.numeric(dplyr::recode(as.character(x), "2" = "20", "4" = "40"))
# [1] 1 20 3 40 5 6 7 8 9 10
# With case_when function
dplyr::case_when(
x %in% 2 ~ 20,
x %in% 4 ~ 40,
TRUE ~ as.numeric(x)
)
# [1] 1 20 3 40 5 6 7 8 9 10
回答3:
Try this:
#sample data
set.seed(123); x <- sample(1:5, size = 10, replace = TRUE)
x
# [1] 2 4 3 5 5 1 3 5 3 3
#recode
x <- c(1, 1, 2, 2, 3)[ x ]
x
# [1] 1 2 2 3 3 1 2 3 2 2
来源：https://stackoverflow.com/questions/24011836/recode-numeric-values-in-r