dec_pos: Number of individuals for which the decision is positive.
Description
dec_pos is a frequency that describes the
number of individuals in the current population N
for which the decision is positive (i.e., called or predicted cases).
Usage
dec_pos
Arguments
Format
An object of class numeric of length 1.
Details
Key relationships:
to probabilities:
The frequency of dec_pos individuals depends on the population size N and
the decision's proportion of positive decisions ppod and is split further into two subsets of
hi by the positive predictive value PPV and
fa by the false detection rate FDR = 1 - PPV.
Perspectives:
by condition:
The frequency dec_pos is determined by the population size N times
the proportion of positive decisions ppod:
dec_pos = N x ppod
by decision:
a. The frequency hi is determined by dec_pos times the positive predictive value PPV
(aka. precision):
hi = dec_pos x PPV
b. The frequency fa is determined by dec_pos times the false detection rate FDR = (1 - PPV):
fa = dec_pos x FDR = dec_pos x (1 - PPV)
to other frequencies:
In a population of size N the following relationships hold:
N = cond_true + cond_false (by condition)
N = dec_pos + dec_neg (by decision)
N = dec_cor + dec_err (by correspondence of decision to condition)
N = hi + mi + fa + cr (by condition x decision)
Current frequency information is computed by
comp_freq and contained in a list
freq.
is_freq verifies frequencies;
num contains basic numeric parameters;
init_num initializes basic numeric parameters;
freq contains current frequency information;
comp_freq computes current frequency information;
prob contains current probability information;
comp_prob computes current probability information.
Other frequencies:
N,
cond_false,
cond_true,
cr,
dec_cor,
dec_err,
dec_neg,
fa,
hi,
mi
dec_pos <- 1000 * .33# => sets dec_pos to 33% of 1000 = 330 cases.is_freq(dec_pos) # => TRUEis_prob(dec_pos) # => FALSE, as dec_pos is no probability (but ppod and PPV are)