how to pick variable names

[rykwong]

Dear SAS community:

I have a large dataset with several thousand variables. 

I need to pick variables using specific texts in their variable names. 

I use this simple code to pick them:

data two; set one;

keep mi:;

run;

this picks up the variables that starts with the name "mi", such as mi_date, mi_size, and mi_treat, but cannot pick up hx_mi, time_mi, and chronic_mi_treat.  is there something simple I can use to pick out variables using "mi" in the variable names regardless of position?

thanks

[Astounding · Accepted solution]

Something simple?  No.  But the complexities are manageable.  Old-style program:

proc contents data=have out=_contents_ (keep=name where=(index(upcase(name), 'MI') > 0));

run;

That gives you a list of all the variable names.  Note that you can use dictionary.columns instead of PROC CONTENTS if that's something y ou are mildly familiar with.

Then get the list into a macro variable (again you have choices at this point, CALL EXECUTE being one alternative):

proc sql;

select strip(name) into : varlist separated by ' ' from _contents_;

quit;

Finally, use the macro variable:

data want;

set have (keep=&varlist);

run;

Note that you can add to the list of variables, such as:

set have (keep=id &varlist);

Finally, consider whether it would be safer (but still accurate) to search for "mi_" instead of "mi".

[rykwong]

many thanks Astounding,

fantastic, this is simple enough

thanks