SAS Time Series Transformation

SAS Code to transform multiple time series with one line per date et per id, in time series with one lien per id.

data a;
input id t v vv;
cards;
1 1 13 51
1 2 16 654
1 3 23 21
2 1 345 3212
2 2 42 22
2 3 34 254
run;

%macro f(v);
proc transpose data = a out = b (drop= _NAME_) prefix = &v;
    var &v;
    id t;
    by id;
run;
%if %sysfunc(exist(res)) %then %do;
    data res;
        merge res b;
        by id;
    run;
%end;
%else %do;
    data res;
        set b;
    run;
%end;
%mend;
%f(v);
%f(vv);
proc print data = res;
run;