Subset dataset to categorical variables only

[dbjosiah]

I'm looking for a way to subset a dataset to only its categorical variables (or only continuous, doesn't matter) without knowing the names of the variables. So far haven't found anything that matches what I need. Thanks for any help.

[PaigeMiller · Accepted solution]

Example:

data cars;
    set sashelp.cars(keep=_character_);
run;

[dbjosiah]

That's so simple it's embarrassing. Thanks.

[Reeza]

It you can assume categorical variables are character.
For example, cylinders in SASHELP.CARS is a categorical categorical variable but numeric.

[dbjosiah]

Thanks Reeza. Once I have the real continuous ones out, I'm subsetting the long character ones by hand.

[Reeza]

If you use SAS Studio, check out the characterize data set task. It does this automatically by looking at the # of distinct values within variables. Anything less than a threshold will be classified as categorical IIRC. 

[dbjosiah]

That would be useful! But I don't use Studio.

[Tom]

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@dbjosiah wrote:
Thanks Reeza. Once I have the real continuous ones out, I'm subsetting the long character ones by hand.

---

You could try NLEVELS output of PROC FREQ to quickly find the number of levels for each variable.

proc freq nlevels data=have;
  tables _all_ / noprint;
run;

[dbjosiah]

I've used nlevels, but never like that! Much better than hand subsetting. Thanks!