using subset but old variables still left
- by user2520852
I am working with a data set, which is basically daily usage data (let's just say variable X and Y) by different cities (about 150 cities). I have created a subset of data for only specific cities, choosing just 3 of the 150 cities.
Then when I do tapply by cities, I get means for 3 cities but also get NA for all other 147 cities that was in the data set. I am using the below coding
df<-read.csv(...)
df_sub<-subset(df,df$City==1|df$City==3|df$City==19)
X_Breakdown<-tapply(X,df_sub$City, mean, na.rm=TRUE)
Print(X_Breakdown)
City 1 City 2
15 NA
City 3 City 4
12 NA
City 5 City 6
NA NA
Hope you get the idea. I would like to get a dataset that only contains the 3 cities that I'm interested in.
It seems that the set of variables is encoded in R, is there a way to fix this? Kindly advise. Thanks
