local_association {zebu} | R Documentation |
Subroutines called by lassie
to compute
local and global association measures from a list of probabilities.
local_association(x, measure, nr) duchers_z(x) pmi(x, normalize = FALSE) npmi(x) chisq(x, nr)
x |
list of probabilities as outputted by |
measure |
name of measure to be used:
|
nr |
number of rows/samples. Only used to estimate chi-squared residuals. |
normalize |
Normalizes pointwise mutual information when calling |
local_association(x, measure = 'z')
is equivalent to
duchers_z(x)
.
local_association(x, measure = 'pmi')
is equivalent to
pmi(x)
.
local_association(x, measure = 'npmi')
is equivalent to
npmi(x)
and pmi(x, normalize = TRUE)
.
List containing the following values:
local: local association array (may contain NA, NaN and Inf values).
global: global association numeric value.
# This is what happens behind the curtains in the 'lassie' function # Here we compute the association between the 'Girth' and 'Height' variables # of the 'trees' dataset # 'select' and 'continuous' take column numbers or names select <- c('Girth', 'Height') # select subset of trees continuous <-c(1, 2) # both 'Girth' and 'Height' are continuous # equal-width discretization with 3 bins breaks <- 3 # Preprocess data: subset, discretize and remove missing data pre <- preprocess(trees, select, continuous, breaks) # Estimates marginal and multivariate probabilities from preprocessed data.frame prob <- estimate_prob(pre$pp) # Computes local and global association using Ducher's Z lam <- local_association(prob, measure = 'z')