/* Homework 2: Factor Analysis on Seishu data     			 		 */
/* WITH SELECTED OUTPUT												 */

OPTIONS PS=52;
OPTIONS LS=78;
OPTIONS NODATE;
OPTIONS PAGENO=1;

DATA WINE;
   INFILE 'A:/SEISHU.PRN';
   INPUT Y1 Y2 X1-X8;
   LABEL Y1 = 'Taste';
   LABEL Y2 = 'Odor';
   LABEL X1 = 'pH';
   LABEL X2 = 'Acidity 1';
   LABEL X3 = 'Acidity 2';
   LABEL X4 = 'Sake Meter';
   LABEL X5 = 'Direct Reducing Sugar';
   LABEL X6 = 'Total Sugar';
   LABEL X7 = 'Alcohol';
   LABEL X8 = 'Formyl-Nitrogen';
RUN;

/* We will first print out the data									 */

PROC PRINT DATA=Wine;
   TITLE 'Data for 30 brands of Japanese Seishu wines';
RUN;

/* Initially we will consider all the X variables          			 */
 
PROC CORR;
   TITLE 'Correlations Of All Eight Explanatory Variables';
   VAR X1-X8;
RUN;

PROC FACTOR CORR MSA SCREE ROTATE = VARIMAX;
   TITLE 'Factor Analysis On All Eight Explanatory Variables';
   VAR X1-X8;
RUN;

/* Once we have decided to exclude X7 from the Factor Analysis, we
   will now just consider X1-X6 and X8. I added MINEIGEN = .9 because,
   having already ran the program once, I wanted to extract a third
   factor															 */

PROC CORR;
   TITLE 'Correlations On Remaining Seven Explantory Variables';
   VAR X1-X6 X8;
RUN;

PROC FACTOR CORR MSA SCREE MINEIGEN = .9 ROTATE = VARIMAX;
   TITLE 'Factor Analysis On Remaining Seven Explantory Variables';
   VAR X1-X6 X8;
RUN;

/* Now trying an oblique PROMAX rotation to compare results			 */

PROC FACTOR CORR MSA SCREE MINEIGEN = .9 ROTATE = PROMAX;
   TITLE 'Factor Analysis On Remaining Seven Explantory Variables With Oblique Rotation';
   VAR X1-X6 X8;
RUN;