* Author: Dr. Jörg Michael Müller, Uni Tübingen, 07071-2978353;
* Adress: Friedrichstrasse 21, 72072 Tübingen, Germany
* Email: JMMueller@uni-tuebingen.de
* 1. Website: http://www.JoergMMueller.de/default.htm
* 2. Website: http://www.psychological-tests.de
*
* Content: SAS-Macro to compute the PDTS and PDPP score of a psychological test;
* Additional information about the macro could be retrieved from the following papers:
*
* Reference: PLEASE CITE IF YOU USE THE PROGRAM: 
* Müller, J. M. (2005). SAS MACROS TO COMPUTE THE PROBABILITY OF DISTINCT TEST RESULTS. Applied Psychological Measurement;
* Müller, J. M. (2005). The Probability of Obtaining Two Statistically Different Test Scores as a Basic Test Characteristic. Educational and Psychological Measurement.
* 
* 
* Table of Contents:
* Name of Macro					* Function:
*******************************************************************************************;
* %Log_on	%Log_on 			* Enable/Disable the SAS-Log
* %mac_on	%mac_on				* Enable/Disable SAS-Macro statements in the Log
* %PDTS(FILE, RELI, SCORE);		* Compute the PDTS;

* To have an example for the PDTS macro, please make the permanent 
* SASfile 'sas_test.sas7bdat' actual in your Work-library, e.g. by an libname statement;



*****************Mini Macro Statements to speed up BEGIN    **********************;
%macro log_on;
options source notes date;
%mend log_on;

%macro log_off;
options nosource nonotes nodate;
%mend log_off;

%macro mac_on;
options mprint merror mlogic serror symbolgen;
%mend mac_on;

%macro mac_off;
options  nomlogic nomprint nomerror nosymbolgen nomrecall;
%mend mac_off;

%log_off
%mac_off
*****************Mini Macro Statements to speed up END    **********************;
 

*****************Macro Content   BEGIN    **********************;
%macro content2(datain, charnum);

%global vmax obs;

data d1; set macro.&datain;
call symput('obs',left(_n_)); run;

proc contents data=macro.&datain noprint out=d2;
%if &charnum=1 %then %do; data d3; set d2; where type=1; %end;
%if &charnum=2 %then %do; data d3; set d2; where type=2; %end;
%if &charnum=3 %then %do; data d3; set d2; %end;

call symput('vmax',left(_n_)); run;

data d4; set d3;

%do i= 1 %to &vmax; %global v&i l&i t&i f&i; %end;
call symput('v'||left(_n_), name);
call symput('l'||left(_n_), label);
call symput('t'||left(_n_), type);
call symput('f'||left(_n_), format);
call symput('p'||left(_n_), npos);

run cancel;

%mend content2;
*****************Macro Content   END      **********************;


*****************Macro PDTS   BEGIN      **********************;
%macro PDTS(FILE, reli, score);
data &score; set &FILE (keep=&score);
	title1; title2; title3; if &score=. then delete; run;

data d1; set &score; call symput('frq',left(_n_));

data _null_; set d1; %let TPU=%eval((&frq * (&frq -1))/2); run;
proc means data=&score noprint; var &score; output out=o std= s;

data _null_; set o; call symput("s",s); run;

data d2; set &score;
	reli=&reli/100;
	krit= 1.96 * (&s * (sqrt (2 * (1-(&reli/100)))));

data d3; set d2;
	call symput ('krit', krit); run;
	proc transpose data=&score out=ot prefix=v;  run;

data d4; set ot;
	array a{*} v1-v&frq;
	array b{*} v1-v&frq;
	EPU=0;
	krit=abs(&krit);
	do i= 1 to &frq;
		do j= i+1 to &frq;
		diff=abs(a{i} - b{j});
		if diff > krit then EPU=EPU+1;
		end;
	end;

data fertig; set d4;
	TPU=&TPU; PDTS=(EPU/TPU)*100; reli=&reli/100; Personen=&frq;
	proc print round; var personen krit reli PDTS;
	title1 "Your test &file ";
	title2 "shows a probability to distinguishing"; 
	title3 "two randomly selected person parameter of PDTS(in %)"; run;
	title1; 	title2; 	title3; run;

%mend PDTS;
*****************Macro PDTS   END      **********************;

*****************Macro PDTS   CALL      **********************;
%PDTS(file, 81, perspara)