topic How to get a summary for the top 5%, 10% and other data in SAS Procedures

How to get a summary for the top 5%, 10% and other data

bncoxuk — Tue, 26 Jul 2011 16:55:42 GMT

I have a sample with one dependent dummary variable y (0, 1). The data has been sorted.

Now the question is how I can get easily get a summary (e.g. mean, freq) for the top 5%, 10%, 15%, 20%, 25%, ... 95% sample. I hope there is a way to do this easily, rather than use separate steps to produce the results. Any procedure to do this, PROC UNIVARIATE, PROC FREQ, PROC MEANS?

How to get a summary for the top 5%, 10% and other data

art297 — Tue, 26 Jul 2011 17:00:22 GMT

You have to tell us more. If you really do only have one dv, and it IS binary, I would think that just proc freq would provide everything that you need. If it is more complex, proc rank might be what you are looking for.

How to get a summary for the top 5%, 10% and other data

data_null__ — Tue, 26 Jul 2011 17:27:59 GMT

If the variable only has 2 levels it cannot be divided into 20 groups.

If you have a continuous variable then PROC RANK will divide the data into 20 groups and you can summarize using the GROUP as a class variable..

proc rank data=sashelp.heart out=g groups=20;

var weight;

ranks g;

run;

proc means data=g;

class g;

var weight;

run;

How to get a summary for the top 5%, 10% and other data

bncoxuk — Tue, 26 Jul 2011 17:42:48 GMT

Sorry that I did not explain clearly.

What I want is to get the descriptive statistics for the top 5% data, top10% data, top 15%... Here, the data have been sorted in a proper order. The descriptive statistics are just for a single variable (which is a dummy type y=0 or 1).

How to get a summary for the top 5%, 10% and other data

data_null__ — Tue, 26 Jul 2011 17:48:39 GMT

Just create a grouping variable based on obs number and total obs that makes 20 groups.

How to get a summary for the top 5%, 10% and other data

art297 — Tue, 26 Jul 2011 19:06:07 GMT

and you may want to look into insight. If you license it, you can activate it by either runing the word insight from the command line, or running the command DM "insight";

I have found it to be an invaluable way to see both the statistics, and graphical representations, of one's data.

Re: How to get a summary for the top 5%, 10% and other data

bncoxuk — Tue, 26 Jul 2011 19:21:30 GMT

Thanks art297. I learned

Re: How to get a summary for the top 5%, 10% and other data

Ksharp — Wed, 03 Aug 2011 03:59:42 GMT

data test;
 do index=1 to 100;
  y=int(ranuni(-1)*2);
  output;
 end;
run;
proc sort data=test ;
 by descending index;
run;

%let dsid=%sysfunc(open(test));
%let nobs=%sysfunc(attrn(&dsid,nobs));
%let dsid=%sysfunc(close(&dsid));

%let want_percent=.2;
%let want_top=%sysevalf(&nobs*&want_percent,integer);
%put _user_;

proc means data=test(obs=&want_top) nway noprint;
 var y;
 output out=want mean= sum=/autoname;
run;

Ksharp