I am working with weatherAUS dataset that is avaiable in the R libraries. I am trying to replace "Yes" to 1 and "No" to 0 in the RainTomorrow column.
I wrote this but it doesn't seem to work:
weather4$RainTomorrow[weather4$RainTomorrow=="Yes"]<-1 I just says:
Warning message: In
[<-.factor(*tmp*, weather4$RainTomorrow =="Yes", value = c(NA, : invalid factor level, NA generated
What does it mean and what should I do? I reckon I should use as.numeric or as.factor somewhere but I don't know how really.
Best Answer
You can easily do this with dplyr.
require(dplyr)weather4 <- weather4 %>%mutate(RainToday = ifelse(RainToday == "No",0,1))Hope this helps
library(data.table) weather4[,":="(RainTomorrow=ifelse(RainTomorrow=="no",0,1))]or simply use:
as.numeric(as.factor(weather4$RainTomorrow))This is a fairly common thing when one is testing different models. For instance, decision trees work well with "Yes" and "No". However some Regression models demands 1 and 0. Particular Logistic Regression.
I solved this by using the plyr library. It was extremely easy and convenient. Here is my solution.
Origin of solution is here.
library(plyr)weather5$RainToday <- revalue(weather5$RainToday, c("Yes"=1))weather5$RainToday <- revalue(weather5$RainToday, c("No"=0))head(weather5$RainToday)[1] 0 1 1 1 1 0Levels: 0 1Peace!