* 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
* %PDPP(FILE, PERSPARA, SEM);		* Compute the PDPP;



* 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;

%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

*****************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 PDPP   BEGIN       **********************;
%macro PDPP(file, PERSPARA, SEM);

* The data file is reduced to the person parameter pp and transposed;
data macro.p1; set &file(keep=&PERSPARA ); run;

* the number of observations = number subject is read;
%content2(p1,3)

proc transpose data=macro.p1 out=macro.pg1 prefix=p;  run;

data macro.pg2; set macro.pg1(drop=_NAME_);

* next the data file is reduced to the standard error of the person parameter and also transposed;
data macro.e1; set &file(keep=&SEM ); 

	proc transpose data=macro.e1 out=macro.eg1 prefix=e;  run;

data macro.eg2; set macro.eg1(drop=_NAME_);

* both files are next connected;
* and the arrays are defined to allow a very quick computing;
data macro.pe; merge macro.pg2 macro.eg2;

	array a{*} p1-p&obs;
	array b{*} p1-p&obs;
	array c{*} e1-e&obs;
	array d{*} e1-e&obs;

* EPU is the number of statistical distinct pairs;
* TPU is the number of all pairs;
	EPU=0;
	TPU=0;

* the distance between a pair is next compared to the LSD least signficant differences in a very long file;
do i= 1   to &obs;
	do j= i+1 to &obs;
	ppk=1.96*sqrt(c{i} + d{j});
	ppd=      abs(a{i} - b{j});

	* Counting significant pairs;
	if ppd > ppk then EPU=EPU+1;
					  TPU=TPU+1;
	end;
end;

data raus; set macro.pe(drop=p1-p&obs e1-e&obs);
	call symput('EPU', EPU);
	call symput('TPU', TPU);

data IRTPDR; set macro.pe;
	Scale="&file";
	PDPP=( &EPU/ &TPU )*100;
	Personen=&obs;

	proc print round; var scale personen PDPP;
	title1 "Your test &file ";
	title2 "shows a probability to distinguishing two randomly"; 
	title3 "selected person parameter of ... (see PDPP in %)"; run;
	title1; 	title2; 	title3; 	run;

%mend PDPP;
*****************Macro PDPP   END      **********************;

*****************Macro PDPP   CALL      **********************;
%PDPP(file, PERSPARA, SEM)