fart: The false alarm rate (or false positive rate) of a decision process or diagnostic procedure.
Description
fart defines a decision's false alarm rate
(or the rate of false positives): The conditional probability
of the decision being positive if the condition is FALSE.
Usage
fart
Arguments
Format
An object of class numeric of length 1.
Details
Understanding or obtaining the false alarm rate fart:
Definition:
fart is the conditional probability
for an incorrect positive decision given that
the condition is FALSE:
fart = p(decision = positive | condition = FALSE)
or the probability of a false alarm.
Perspective:
fart further classifies
the subset of cond_false individuals
by decision (fart = fa/cond_false).
Alternative names:
false positive rate (FPR),
rate of type-I errors (alpha),
statistical significance level,
fallout
Relationships:
a. fart is the complement of the
specificity spec:
fart = 1 - spec
b. fart is the opposite conditional probability
-- but not the complement --
of the false discovery rate
or false detection rate FDR:
FDR = p(condition = FALSE | decision = positive)
In terms of frequencies,
fart is the ratio of
fa divided by cond_false
(i.e., fa + cr):
fart = fa/cond_false = fa/(fa + cr)
Dependencies:
fart is a feature of a decision process
or diagnostic procedure and a measure of
incorrect decisions (false positives).
However, due to being a conditional probability,
the value of fart is not intrinsic to
the decision process, but also depends on the
condition's prevalence value prev.
comp_fart computes fart as the complement of specprob contains current probability information;
comp_prob computes current probability information;
num contains basic numeric parameters;
init_num initializes basic numeric parameters;
comp_freq computes current frequency information;
is_prob verifies probabilities.
Other probabilities:
FDR,
FOR,
NPV,
PPV,
acc,
err,
mirt,
ppod,
prev,
sens,
spec
fart <- .25 # sets a false alarm rate of 25%fart <- 25/100# (decision = positive) for 25 out of 100 people with (condition = FALSE)is_prob(fart) # TRUE