Combining more than 2 columns by removing NA's in R

Question

At first sight this seems a duplicate of Combine/merge columns while avoiding NA? but in fact it isn\'t. I am dealing sometimes with more than two columns instead of just tw

Answer 1

You can use apply for this. If df is your dataframe`:

df2 <- apply(df,1,function(x) x[!is.na(x)])
df3 <- data.frame(t(df2))
colnames(df3) <- colnames(df)[1:ncol(df3)]

Output:

#      col1 col2
#         1   13
#        10   18
#         7   15
#         4   16