topic Re: Suggestion for new automatic macro variable SYSNVAR in SAS Programming

Suggestion for new automatic macro variable SYSNVAR

HuggyBob — Wed, 04 Nov 2015 14:30:31 GMT

I am aware of the automatic macro variables SYSNOBS and SQLOBS, which tell me how many observations in a new table, but we do not seem to have one for number of variables. DICTIONARY.TABLES gives me NVAR, which tells me what I want, but I am surprised that we do not have a corresponding macro variable such as SYSNVAR.

Re: Suggestion for new automatic macro variable SYSNVAR

RW9 — Wed, 04 Nov 2015 15:18:04 GMT

Well, wasn't aware of these ones, I have always queried the metadata tables. I suppose its because you should know the structure of your data, as knowing how many variables doesn't help much, I mean you can't really use that info. However I like the idea, and it is part of the wider discussion on how to access the metadata of the system. Personally I don't like the macro variable way of doing things. In my way of thinking metadata should be accessible via a function, which can then be used directly in code explicitly on any dataset not just the last one, maybe something like:

metadata(library=work,member=,property=[,where=]);

So you could use it:

number_of_observations=metadata(library=sashelp,member=cars,property=nobs);

number_of_variables=metadata(library=sashelp,member=cars,property=nvar);

Maybe you want to create an array for all col variables:

array list_col{*} metadata(library=sashelp,member=cars,property=vars,where=%str(substr(varname,1,3)="COL"));

So a function that can return any of the metadata, not just obs, vars, but any property from table or columns.

Re: Suggestion for new automatic macro variable SYSNVAR

Reeza — Wed, 04 Nov 2015 17:53:25 GMT

SAS has a semiformal method for making suggestions, you can post a new idea in the SAS ballotware section so others can vote on the idea.

https://communities.sas.com/t5/SASware-Ballot-Ideas/idb-p/sas_ideas

Re: Suggestion for new automatic macro variable SYSNVAR

JoshB — Fri, 06 Nov 2015 19:06:58 GMT

Something you are probably aware of, but maybe others are not.

I've always used sysfunc/qsysfunc with attrn or attrc functions to get to these metadata entries if I want to use functions or store things into macro variables. i.e., for the task at hand for number of variables.

%let rc = %sysfunc(open(WORK.HAVE));
%let nvars = %sysfunc(attrn(&rc.,nvars));
%let rc = %sysfunc(close(WORK.HAVE));

%put &nvars.;

The nice thing about these is they can be used in open code or in macros (in my experience).

Other available attributes are viewable here

Re: Suggestion for new automatic macro variable SYSNVAR

RW9 — Thu, 05 Nov 2015 09:33:38 GMT

Yes, I quite agree. The only thing I would say is that the need to do an close(open(function)) syntax is not ideal. We should be able to pull metadata items using one simple function, which doesn't require opening/closing files, but just returns a query of the metdata tables.

Re: Suggestion for new automatic macro variable SYSNVAR

JoshB — Fri, 06 Nov 2015 19:05:50 GMT

Definitely true. Speaking of, I should probably add that to the end in case someone uses it and doesn't know to close.