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ci.exact <-
function(x, y, accuracy.measure, z, t, conf.level) {
F1 <- suppressWarnings(qf(1-((1-conf.level)/2), 2*(x+1), 2*y))
F2 <- suppressWarnings(qf(1-((1-conf.level)/2), 2*(y+1), 2*x))
if (accuracy.measure == "Negative Predictive Value" | accuracy.measure == "Positive Predictive Value") {
F3 <- suppressWarnings(qf(1-((1-conf.level)/2), 2*(z+1), 2*t))
F4 <- suppressWarnings(qf(1-((1-conf.level)/2), 2*(t+1), 2*z))
}
if (accuracy.measure == "Sensitivity" | accuracy.measure == "Specificity") {
ll <- y/(((x+1)*F1)+y)
ul <- ((y+1)*F2)/(x+(y+1)*F2)
}
if (accuracy.measure == "Positive Predictive Value") {
ll <- y/(y+(z+1)*F3)
ul <- ((y+1)*F2)/(z+(y+1)*F2)
}
if(accuracy.measure == "Negative Predictive Value") {
ll <- t/(t+(x+1)*F1)
ul <-((t+1)*F4)/(x+(t+1)*F4)
}
if(((accuracy.measure == "Sensitivity" | accuracy.measure == "Specificity") & any(is.nan(F1), is.nan(F2)))
|| (accuracy.measure == "Positive Predictive Value" & any(is.nan(F3), is.nan(F2)))
|| (accuracy.measure == "Negative Predictive Value" & any(is.nan(F1), is.nan(F4)))) {
warning(paste(accuracy.measure, " CI: \"Exact\" method may not be valid for some values (see Help Manual).\n", sep = ""), call. = FALSE, immediate. = TRUE)
}
res <- list (ci = matrix(c(ll,ul), ncol = 2))
}
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