 
 R requires the table in this format:
Explanatory variable ⇓  Response variable ⇓ 
−  + 
Reference  800  3 
+  17  1 
 tabodds = matrix(c(800,17,3,1),nc=2) enters the table column by column into the variable 'tabodds'.
 nc = 2 instructs R that there are two columns.
 oddsratio.wald specifies the unconditional maximum likelihood estimate of the odds ratio and the normal approximation (Wald) confidence interval.
 oddsratio.fisher specifies the conditional maximum likelihood estimate of the odds ratio and the exact confidence interval.
 oddsratio.midp specifies the median unbiased estimate of the odds ratio and the midp exact confidence interval.
