I have a long list of very large SAS files. I want to import them using read_sas. To increase speed and reduce memory usage I want to only import the columns I am interested in using cols_only.
The trouble is, I have a long list of possible column names - but not every column is in my dataset. If I pass the full list to cols_only, I get the error:
Evaluation error: Column 2 must be named.
Is there a way to suppress this error, and encourage read_sas to do its best to import whatever variables it can from the list I have passed?
As @Andrew mentions in their comment, with haven >= 2.2.0 you can use the new col_select argument for this. To select columns that may not exist, use the helper one_of():
library(haven)
library(tidyselect)
f <- tempfile()
write_sas(mtcars, f)
my_cols <- c("mpg", "i-don't-exist")
read_sas(f, col_select = one_of(my_cols))
#> Warning: Unknown columns: `i-don't-exist`
#> # A tibble: 32 x 1
#> mpg
#> <dbl>
#> 1 21
#> 2 21
#> 3 22.8
#> 4 21.4
#> 5 18.7
#> 6 18.1
#> 7 14.3
#> 8 24.4
#> 9 22.8
#> 10 19.2
#> # ... with 22 more rows