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When merging datasets, be sure the same variable names are not used

Whe merging data A and B and if A and B has variables that happen to have the same variable name, one of them will be deleted. For example, if A has "GPA" meaning individual-level GPA and if B has GPA meaning school-level GPA, one of them will be deleted after the merge.

data A;
gpa=1.2;
run;

data B;
gpa=999;
run;

data both;
merge A B;
run;

proc print;
run;

RESULT:
Obs gpa
1 999

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Time function MDY( )

data x;
/*first=download_date=MDY(&x_month,&x_day,&x_year);*/
first=mdy(9,2,2012);
last=mdy(5,15,2013);
count=last-first;
run;
proc print;run;

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Factor analysis of Dichotomous Items

/*
http://support.sas.com/onlinedoc/913/getDoc/en/statug.hlp/factor_sect22.htm
http://support.sas.com/ctx/samples/index.jsp?sid=512
*/
/*place a SAS macro somewhere in your PC*/

%let dataname=amy;
%let name_of_doc=xxxxx\tetra_result.txt;

%include "xxxxxxxxxxxxx\sample00512_1_polychor.sas";

data raschdata;
set &dataname;
run;

data raschdata2;
set raschdata;
xxx=.;
keep
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

;
run;

%let abc=&syslast;
data _null_;set &abc end=end;
array test (*) _numeric_; array allmiss (3000) $ (3000*'true');
length list $ 5000; do i=1 to dim(test); if test(i) ne . then allmiss(i)='false';
end; if end=1 then do i= 1 to dim(test);
if allmiss(i) ='true' then list=trim(list)||' '||trim(vname(test(i)));
end; call symput('mlist',list);
run;
data &abc ; set &abc ; drop &mlist;run;
PROC SQL NOPRINT;
SELECT TRIM(NAME)
INTO :VARLIST SEPARATED BY ' '
FROM DICTIONARY.COLUMNS
WHERE LIBNAME EQ "WORK" AND MEMNAME EQ "RASCHDATA2"
ORDER BY VARNUM;
QUIT;

proc means data=raschdata2 ;
output out=meanresult;
var &varlist;
run;

data meanresult2;
set meanresult;
if _stat_="STD";
array kazu _numeric_ ;
do over kazu;
if kazu=0 then kazu=.;
end;
xxx=.;
run;
%let abc=&syslast;
data _null_;set &abc end=end;
array test (*) _numeric_; array allmiss (3000) $ (3000*'true');
length list $ 5000; do i=1 to dim(test); if test(i) ne . then allmiss(i)='false';
end; if end=1 then do i= 1 to dim(test);
if allmiss(i) ='true' then list=trim(list)||' '||trim(vname(test(i)));
end; call symput('mlist',list);
run;
data &abc ; set &abc ; drop &mlist _freq_ _stat_;run;

PROC SQL NOPRINT;
SELECT TRIM(NAME)
INTO :VARLIST SEPARATED BY ' '
FROM DICTIONARY.COLUMNS
WHERE LIBNAME EQ "WORK" AND MEMNAME EQ "MEANRESULT2"
ORDER BY VARNUM;
QUIT;

%polychor(data=raschdata,var=&varlist,maxiter=200,out=result);

/*just to get the name first*/
data result2;
retain _name_;
set result;
run;

PROC EXPORT DATA= result2 OUTFILE= "C:\temp\matrix.xls"
DBMS=EXCEL2000 REPLACE;
RUN;

option NOCENTER;
PROC PRINTTO PRINT="&name_of_doc" new;
RUN;
options formdlim=' ';

data one (type=corr);
set result2;
run;

proc factor data=one
method=prinit
n = 2
rotate = v
scree;
*where _type_="CORR";
var &varlist
;
run;

proc factor data=one
method=prin priors=smc
n = 2
rotate = v
scree;
var
&varlist
;
run;

PROC PRINTTO PRINT=PRINT;
run;
quit;

x "notepad &name_of_doc";

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HLM equation and PROC MIXED/GLIMMIX syntax

level1 : y= b0 + b1*X + error1
level2: b0=g00 + g01*group+error2
level2: b1=g10 + g11*group + error3

I insert level2 equations into level 1.

level1 : y= g00 + g01*group+error 1+ (g10 + g11*group + error2)*X + error3

level1 : y= g00 + g01*group+error 1+ g10*X + g11*group *X + error2*X + error3

This translates into PROC MIXED syntax in this way.  Independent variables that are right next to the error (error2*X) goes into the random statement.

proc mixed ;
class sub group ;
model y=x group x*group;
random intercept x;
run;