# local_association: Local Association Measures In oliviermfmartin/zebu: Local Association Measures

 local_association R Documentation

## Local Association Measures

### Description

Subroutines called by `lassie` to compute local and global association measures from a list of probabilities.

### Usage

``````local_association(x, measure = "chisq", nr = 1)

lewontin_d(x)

duchers_z(x)

pmi(x, normalize)

chisq(x, nr)
``````

### Arguments

 `x` list of probabilities as outputted by `estimate_prob`. `measure` name of measure to be used: 'chisq': Chi-squared residuals. 'd': Lewontin's D. 'z': Ducher's 'z'. 'pmi': Pointwise mutual information (in bits). 'npmi': Normalized pointwise mutual information (Bouma). 'npmi2': Normalized pointwise mutual information (Multivariate). `nr` number of rows/samples. Only used to estimate chi-squared residuals. `normalize` 0 for pmi, 1 for npmi, 2 for npmi2

### Value

List containing the following values:

• local: local association array (may contain NA, NaN and Inf values).

• global: global association numeric value.

`lassie`

### Examples

``````# 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')
``````

oliviermfmartin/zebu documentation built on Sept. 1, 2023, 9:12 p.m.