goptions reset=global gunit=in
         ftitle="garamond" ftext="garamond" htitle=.5 htext=.3;

Title1 'T-Tests and Confidence Limits';

PROC IMPORT OUT= WORK.TIMETECH 
            DATAFILE= "F:\Courses\anth588\TimeTech.xls" 
            DBMS=EXCEL2000 REPLACE;
     GETNAMES=YES;
RUN;


data Proj4Data; set timetech;
  if 	(site = 'APPLECRK' and prov='F203') or
  		(site = 'MACOUPIN' and prov='F173') or
		(site = 'BOULDER' and prov='F59') or
		(site = 'BRIDGES' and prov='F70');
logavth=log(avth);

Proc sort data =Proj4DataNew;
	by site;


/* We use Proc Means to compute the summary stats we need to get the CL's -- 
	and while we're at it, have Proc Means compute the CL's , so we can check 
	our work */

proc means data=Proj4Data N mean stderr CLM Alpha=.05  nway;
    class site;
	var logavth;
	output out= sumstats 
		n=n
		mean=mean
		std=std
		stderr=stderr;


/* use a data step to get the CL's -- note the t-inverse function */

data sumstats; set sumstats;
		df= n-1;
		UpperCL= mean + stderr * tinv(.975,df);
		LowerCL= mean + stderr * tinv(.025,df);
		Run;

proc print;
 

/* a data step with a subsetting IF statement to pull out PAIRS
of sites for the t-tests*/

data twosites; set timetech;
  if 	(site = 'APPLECRK' and prov='F203') or
  		(site = 'MACOUPIN' and prov='F173');

proc ttest data=twosites;
	class site;
	var logavth mindiam;

run;

/* Use GLM to do an (unbalanced) ANOVA on all four sites. 
We also ask for t-tests on the site means */

proc glm data= Proj4Data;
  class site;
  model logavth=site / solution alpha=.05 clparm;
  lsmeans site / tdiff pdiff alpha=.05 cl;   *for bonferroni Adjustment use -- adjust=bon;
run;