将所有列与tidyr一起使用

Question

I want to unite all the columns in a tibble into one for later processing. Whenever I attempt to do this, I get the error

Error in if (!after) c(values, x) else if (after >= lengx) c(x, values) else c(x[1L:after], : missing value where TRUE/FALSE needed

The tidyr:unite documentation says you can do this by not specifying any columns. Here's a toy example:

ex <- as_tibble(matrix(rnorm(20), ncol = 4))
ex
unite(ex, 'new')

Am I just missing some tidyverse subtlety or...?

Answer 1

How about

df <- ex %>%
unite(ex,1:ncol(ex),sep=" ") 

Answer 2

So, I believe you need to specify the columns even if you want to combine all of them.

To do this, you can just use 1:x where x is the last column number, you don't need to write them all out. For example, in your code you would put:

unite(ex, new, 1:4, sep="")

Remember to put the sep= argument in as well - sep="" means they'll be joined together with no gaps, but sep="." means there will be a dot in between.

Hope that is still of use!

edit: to make it easier to use the column numbers instead of names, you can use ncol() to find the number of columns to specify, eg ncol(ex) returns 4 in your example.