TITLE "HOMEWORK 6";
OPTIONS nodate PAGENO=1;

libname labdata "c:\temp\labdata";
title "Problem 1";
proc freq data=labdata.afifi;
  tables shoktype inshock shockdum2-shockdum7;
run;
proc means data=labdata.afifi;
  class shoktype;
  var sbp2;
run;
proc means data=labdata.afifi;
  class inshock;
  var sbp2;
run;

/*Question 2: Box Plots*/
title "Question 2";
proc sort data=labdata.afifi;
  by shoktype;
run;
proc boxplot data=labdata.afifi;
  plot sbp2 * shoktype / boxstyle=schematic;
run;
proc sort data=labdata.afifi;
  by inshock;
run;
proc boxplot data=labdata.afifi;
  plot sbp2 * inshock / boxstyle=schematic;
run;

/*Question 3: Regression with Dummy Variables.
              Level 2 of Shoktype is reference.*/
title "Question 3";
proc reg data=labdata.afifi;
  model sbp2 = shockdum3 shockdum4 shockdum5 shockdum6 shockdum7;
  plot residual.*predicted.;
  output out=outreg1 p=predict r=resid;
run;
proc univariate data=outreg1 plot normal;
  var resid;
  histogram;
  qqplot / normal(mu=est sigma=est);
run;quit;

/*Question 4: Regression with Dummy Variables.
              Level 7 of Shoktype is reference.*/
title "Question 4";
proc reg data=labdata.afifi;
  model sbp2 = shockdum2 shockdum3 shockdum4 shockdum5 shockdum6;
  plot residual.*predicted.;
  output out=outreg1 p=predict r=resid;
run;


/*Question 5: Regression with Dummy Variables.
              Non-shock is reference.*/
title "Question 5";
proc reg data=labdata.afifi;
  model sbp2 = shockdum3 shockdum4
               shockdum5 shockdum6 shockdum7
               age sbp1 cardiac1;
  shockdum: test shockdum3=0, shockdum4=0,
                 shockdum5=0, shockdum6=0, shockdum7=0; 
run;

/*Question 6: Regression with INSHOCK, plus continuous
              covariates as predictors.
              Non-Shock is reference.*/
title "Question 6";
proc reg data=labdata.afifi;
  model sbp2 = inshock
               age sbp1 cardiac1; 
run;quit;


"	Age
"	Sex 
"	Systolic blood pressure at time 1
"	Diastolic blood pressure at time 1
"	Urinary output at time1
"	Heart rate at time1
"	Central venous pressure at time 1
"	Cardiac output at time 1
"	Appearance time at time 1
"	Circulation time at time 1
"	Plasma level at time 1
"	Red cell level at time 1
"	Hemoglobin level at time 1
"	Hematocrit at time 1

title "Question 7";
proc reg data=labdata.afifi;
  model map2 = age sex sbp1 dbp1 urine1
               heart1 cvp1 cardiac1 apptime1
               circ1 plasma1 redcell1 hgb1 hct1
               / selection = stepwise; 
run;quit;

title "Question 7";
proc reg data=labdata.afifi;
  model map2 = age sex sbp1 dbp1 urine1
               heart1 cvp1 cardiac1 apptime1
               circ1 plasma1 redcell1 hgb1 hct1
               / selection = backward; 
run;quit;

proc reg data=labdata.afifi;
  model map2 = age sex sbp1 dbp1 urine1
               heart1 cvp1 cardiac1 apptime1
               circ1 plasma1 redcell1 hgb1 hct1
               / selection = rsquare best=5 ; 
run;quit;