| comp_prob_freq {riskyr} | R Documentation |
Compute probabilities from (4 essential) frequencies.
Description
comp_prob_freq computes current probability information
from 4 essential frequencies
(hi, mi, fa, cr).
It returns a list of 11 frequencies freq
for a population of N individuals
as its output.
Usage
comp_prob_freq(hi = freq$hi, mi = freq$mi, fa = freq$fa, cr = freq$cr)
Arguments
hi |
The number of hits |
mi |
The number of misses |
fa |
The number of false alarms |
cr |
The number of correct rejections |
Details
Key relationships between frequencies and probabilities
(see documentation of comp_freq or comp_prob for details):
Three perspectives on a population:
by condition / by decision / by accuracy.
Defining probabilities in terms of frequencies:
Probabilities can be computed as ratios between frequencies, but beware of rounding issues.
Functions translating between representational formats:
comp_prob_prob, comp_prob_freq,
comp_freq_prob, comp_freq_freq
(see documentation of comp_prob_prob for details).
See Also
comp_freq_freq computes current frequency information from (4 essential) frequencies;
comp_freq_prob computes current frequency information from (3 essential) probabilities;
comp_prob_prob computes current probability information from (3 essential) probabilities;
num contains basic numeric parameters;
init_num initializes basic numeric parameters;
prob contains current probability information;
comp_prob computes current probability information;
freq contains current frequency information;
comp_freq computes current frequency information;
is_prob verifies probability inputs;
is_freq verifies frequency inputs.
Other functions computing probabilities:
comp_FDR(),
comp_FOR(),
comp_NPV(),
comp_PPV(),
comp_accu_freq(),
comp_accu_prob(),
comp_acc(),
comp_comp_pair(),
comp_complement(),
comp_complete_prob_set(),
comp_err(),
comp_fart(),
comp_mirt(),
comp_ppod(),
comp_prob(),
comp_sens(),
comp_spec()
Other format conversion functions:
comp_freq_freq(),
comp_freq_prob(),
comp_prob_prob()
Examples
## Basics:
comp_prob_freq() # => computes prob from current freq
## Beware of rounding:
all.equal(prob, comp_prob_freq()) # => would be TRUE (IF freq were NOT rounded)!
fe <- comp_freq(round = FALSE) # compute exact freq (not rounded)
all.equal(prob, comp_prob_freq(fe$hi, fe$mi, fe$fa, fe$cr)) # is TRUE (qed).
## Explain by circular chain (compute prob 1. from num and 2. from freq)
# 0. Inspect current numeric parameters:
num
# 1. Compute currently 11 probabilities in prob (from essential probabilities):
prob <- comp_prob()
prob
# 2. Compute currently 11 frequencies in freq (from essential probabilities):
freq <- comp_freq(round = FALSE) # no rounding (to obtain same probabilities later)
freq
# 3. Compute currently 11 probabilities again (but now from frequencies):
prob_freq <- comp_prob_freq()
prob_freq
# 4. Check equality of probabilities (in steps 1. and 3.):
all.equal(prob, prob_freq) # => should be TRUE!