odds.ratio {HH} | R Documentation |
Calculate or plot the odds ratio for a 2x2 table of counts. The plot shows the confidence intervals on the probability of row2 for fixed odds ratio and specified probability for row1.
odds.ratio(x, alpha = 0.05) plot.odds.ratio(x, ylab = "prob(col1 | row1)", xlab = "prob(col1 | row2)", alpha = c(0.05, 0.5), legend.x=1.05, oma=c(0,0,0,5), ...)
x |
2 x 2 table of counts |
alpha |
Significance levels of test.
odds.ratio requires a single number in the range [0,1].
plot.odds.ratio accepts more than one number on the range
[0,1] and draws confidence lines at each value. |
xlab,
ylab |
x- and y-labels for the plot. Sensible defaults are generated. |
... |
other arguments, currently ignored. |
legend.x |
x position of left-hand side of legend. |
oma |
outer margin par()$oma , needed to make room for legend. |
plot.odds.ratio
draws a plot and invisibly returns the same
list as odds.ratio
for the first value of alpha
.
odds.ratio
returns the list:
p1, p2 |
proportion of each row total observed in the first column. |
omega1, omega2 |
odds for each row, p/(1-p) |
psihat |
odds ratio, omega2/omega1 |
s.ln.psihat |
standard deviation of ln(psihat) |
ci.ln.psihat |
confidence interval for ln(psihat)
using normal approximation |
ci.psihat |
confidence interval for psihat calculated
ase p(ci.ln.psihat) |
prob1 |
seq(0,1,.05) , set of p1 values for plotting. |
odds1 |
p1/(1-p1) |
odds2 |
odds for the second row needed to retain psihat with
the specified odds1 , calculated as odds1*psihat . |
ci.odds2 |
confidence interval for odds2 |
prob2 |
odds2 / (odds2+1) |
ci.prob2 |
ci.odds2 / (ci.odds2+1) |
Richard M. Heiberger <rmh@temple.edu>
Heiberger, Richard~M. and Holland, Burt (2004b). Statistical Analysis and Data Display: An Intermediate Course with Examples in S-Plus, R, and SAS. Springer Texts in Statistics. Springer. ISBN 0-387-40270-5.
glasses <- read.table(hh("datasets/glasses.dat"), header=FALSE) glasses <- matrix(unlist(glasses), nrow=2, dimnames=list( c("glasses","no.glasses"), c("delinq","non.del"))) ## draw the iso-odds ratio plot with 50% CI and 95% CI, ## invisibly return the 95% CI plot.odds.ratio(glasses)