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 two.

My dataframe looks like this:

     col1 col2 col3 col4 col5
[1,]    1   NA   NA   13   NA
[2,]   NA   NA   10   NA   18
[3,]   NA    7   NA   15   NA
[4,]    4   NA   NA   16   NA

Now I want to "collapse" this dataframe into a dataframe with less columns and with removed NA's. In fact I am looking for and "excel way of doing": removing one cell and the whole row will move one cell to the left.

The result in this example case would be:

     col1 col2 
[1,]    1   13   
[2,]   10   18   
[3,]    7   15   
[4,]    4   16   

has anyone an idea about how to do this in R? Many thanks in advance!

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