the population size N
the number of cases for which cond_true
the number of cases for which cond_false
the number of cases for which dec_pos
the number of cases for which dec_neg
the number of cases for which dec_cor
the number of cases for which dec_err
the number of true positives, or hits hi
the number of false negatives, or misses mi
the number of false positives, or false alarms fa
the number of true negatives, or correct rejections cr
These frequencies are computed from basic parameters
(contained in num
) and computed by using
comp_freq
.
The list freq
is the frequency counterpart
to the list containing probability information prob
.
Natural frequencies are always expressed in
relation to the current population of
size N
.
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).
Visualizations of current frequency information
are provided by plot_prism
and
plot_icons
.