Replacing values in a column with dplyr using logical statements
- 1 minIf I have a dataframe (dat) with two columns, and there are NA values in one column (col1) that I want to specifically replace into zeroes (or whatever other value) but only in rows with specific values in the second column (col2) I can use mutate, replace and which in the following way.
library(dplyr)
#Example dataframe
dat <- data.frame(col1 = c(1, 2, 3, NA, NA, NA, 3, 2, 1, 0), col2 = c("Tom", "Dick", "Harry", "Dick", "Tom", "Harry", "Harry", "Dick", "Tom", "Harry"))
print(dat)## col1 col2
## 1 1 Tom
## 2 2 Dick
## 3 3 Harry
## 4 NA Dick
## 5 NA Tom
## 6 NA Harry
## 7 3 Harry
## 8 2 Dick
## 9 1 Tom
## 10 0 Harrydat <- dat %>% mutate(col1 = replace(col1, which(is.na(col1) & col2 == "Tom"), 0))
print(dat)## col1 col2
## 1 1 Tom
## 2 2 Dick
## 3 3 Harry
## 4 NA Dick
## 5 0 Tom
## 6 NA Harry
## 7 3 Harry
## 8 2 Dick
## 9 1 Tom
## 10 0 Harry
Danny Wong
Anaesthetist & Health Services Researcher