How to recode variables in table 1 using info from table 2 (in SAS)

Question

The overal goal is to stratify quantitative variables based on their percentile. I would like to break it up into 10 levels (e.g. 10th, 20th, ...100th percentile)

Answer 1

The following should work for you dynamically with no hard-coding -- I edited to compact it into a single macro. Essentially it puts your desired variables into a list, creates a dataset using your output, and then uses the variable contents to put your data steps into long strings. These strings are then put into a macro variable and you can call it in your final data step. Again, no hard-coding involved.

%MACRO stratify(library=,input=,output=);
%local varlist varlist_space data_step_list;

    ** get vars into comma-separated list and space-separated list **;
    proc sql noprint;
        select NAME
        into: varlist separated by ","
        from dictionary.columns
        where libname=upcase("&library.") and memname=upcase("&input.");

        select NAME
        into: varlist_space separated by " "
        from dictionary.columns
        where libname=upcase("&library.") and memname=upcase("&input.");
    quit;

    %percentiles(%bquote(&varlist.)); 

    ** put data into long format **;
    proc transpose data = pcts out=pcts_long;
        by recode percentile;
        var &varlist_space.;
    run;

    ** sort to get if-else order **;
    proc sort data = pcts_long;
        by _NAME_ percentile;
    run;

    ** create your if-then strings using data itself **;
    data str; 
        length STR $100;
        set pcts_long;
        bin = percentile/10;
        by _NAME_;
        if first._NAME_ then do;
            STR = "if "||strip(_NAME_)||" <= "||strip(put(COL1,best.))||" then "||catx("_","recode",_NAME_)||" = "||strip(put(bin,best.))||";";
        end;
        else do;
            STR = "else if "||strip(_NAME_)||" <= "||strip(put(COL1,best.))||" then "||catx("_","recode",_NAME_)||" = "||strip(put(bin,best.))||";";
        end;
    run; 

    ** put strings into a list **;
    proc sql noprint;
        select STR
        into: data_step_list separated by " "
        from STR;
    quit;

    ** call data step list in final data **;
    data &output.; set &input.;
        &data_step_list.;
    run;

    proc print data = &output.(obs=5);
    run;

%MEND;

%stratify(library=work,input=test,output=final);