options ls=90;

filename foo2 url "http://www.uvm.edu/~abh/stat295/datasets/trees2002.dat";
filename foo4 url "http://www.uvm.edu/~abh/stat295/datasets/trees2004.dat";
filename foo6 url "http://www.uvm.edu/~abh/stat295/datasets/trees2006.dat";

data trees02;
     infile foo2;
	 input plot tree treatment $  dbh02;
run;

data trees04;
     infile foo4;
	 input plot tree treatment $  dbh04;
run;

data trees06;
     infile foo6;
	 input plot tree treatment $  dbh06;
run;

proc sort data=trees02;
     by plot tree;
run;

proc sort data=trees04;
     by plot tree;
run;

proc sort data=trees06;
     by plot tree;
run;

data trees020406;
     merge trees02 trees04 trees06;
	 by plot tree;
run;

proc print data=trees020406;
title "Tree diameters in 2002, 2004, and 2006";
run;

data treesuni1;
	set trees020406;

	year = 2002;
	dbh = dbh02;
	output;

	year = 2004;
	dbh = dbh04;
	output;

	year = 2006;
	dbh = dbh06;
	output;

drop dbh02 -- dbh06;
run;

proc print data=treesuni1;
title "Rearranged in univariate form by long method";
run;

data treesuni2;
	set	trees020406;
	array d {3}	dbh02 -- dbh06;

	do i = 1 TO 3;
		dbh = d{i};
		year = 2000 + 2*i;
		output;
	end;

drop dbh02 -- dbh06 i;
run;

proc print data=treesuni2;
title "Rearranged in univariate form using ARRAY statement";
run;

proc compare base=treesuni1 compare=treesuni2;
run;

proc transpose data=trees020406 out=treesuni3;
	by plot tree treatment;
	var	dbh02 -- dbh06;
RUN;

data treesuni3;
	set treesuni3;
	year = 2000 + substr(_NAME_,4);
	rename col1 = dbh;
	drop _NAME_;
run;

proc print data = treesuni3;
title "Rearranged in univariate form using PROC TRANSPOSE";
run;

proc compare base=treesuni2 compare=treesuni3;
run;