Using BY to Draw Many HISTOGRAMs in PROC UNIVARIATE

[Junyong]

How can I output multiple HISTOGRAM image files with BY in PROC UNIVARIATE? Suppose I have the following panel data set.

data _;
do i=1 to 5;
do t=1 to 5;
x=rannor(1);
output;
end;
end;
run;

I tried the following code, but it just overwrote the destination file five times.

filename _ "!userprofile\desktop\_.png";
goption gsfname=_ device=png gsfmode=replace;
ods results=off;
proc univariate noprint;
var x;
by i;
histogram/normal(noprint);
run;
ods results=on;

Here is the log.

11   filename _ "!userprofile\desktop\_.png";
12   goption gsfname=_ device=png gsfmode=replace;
13   ods results=off;
14   proc univariate noprint;
15   var x;
16   by i;
17   histogram/normal(noprint);
18   run;

NOTE: 11265 bytes written to C:\Users\Junyong\desktop\_.png.
NOTE: The above message was for the following BY group:
      i=1
NOTE: 11665 bytes written to C:\Users\Junyong\desktop\_.png.
NOTE: The above message was for the following BY group:
      i=2
NOTE: 10306 bytes written to C:\Users\Junyong\desktop\_.png.
NOTE: The above message was for the following BY group:
      i=3
NOTE: 11258 bytes written to C:\Users\Junyong\desktop\_.png.
NOTE: The above message was for the following BY group:
      i=4
NOTE: 10640 bytes written to C:\Users\Junyong\desktop\_.png.
NOTE: The above message was for the following BY group:
      i=5
NOTE: PROCEDURE UNIVARIATE used (Total process time):
      real time           0.65 seconds
      cpu time            0.65 seconds


19   ods results=on;

Is there any way to collect the five HISTOGRAMs separately?

[Criptic]

If you need an image per seperate histogram my suggestion would be using a macro like this:

%macro multiple_outputs(i);
	filename _&i. "!userprofile\desktop\_&i..png";
	goption gsfname=_ device=png gsfmode=replace;
	ods results=off;

	data work.temp;
		set _;
		where i = &i.;
	run;

	proc Univariate noprint;
		var x;
		by i;
		histogram/normal(noprint);
	run;

	ods results=on;
%mend multiple_outputs;

data _null_;
	set _;
	by i;

	if first.i then
		do;
			arg1 = '%nrstr(%multiple_outputs('!!i!!'));';
			call execute(arg1);
		end;
run;

But I believe somebody will have a solution without having to fall back on macro code which would be a better solution, but I don't know one. I hope this helps you anyways.

Kind Regards

Criptic

[BrunoMueller · Accepted solution]

Proc UNIVARIATE uses ODS Graphics 

You can achieve this as follows:

data have;
  do i=1 to 5;
    do t=1 to 5;
      x=rannor(1);
      output;
    end;
  end;
run;

ods _all_ close;

ods listing gpath="c:\temp";
ods graphics on;
ods graphics / reset=index imagefmt=png imagename="hist_#byval(i)";
title "Histogram for #byline";

proc univariate data=have noprint;
  var x;
  by i;
  histogram/normal(noprint) odstitle=title;
/*  format i z3.;*/
run;

title;

Some notes on the code.

• Using the ODS LISTING destination you can specify the GPATH option to say where the graphics files are written too.
• Since SAS9.4M5 you can make use of the #BY... substitutions in the IMAGENAME option of ODS GRAHICS like you could in the TITLE statement, but now for the image name, otherwise is just numbers them. 
• To have the TITLE text in your graphics file you use the ODSTITLE=TITLE option on the HISTOGRAM statement