assoc.catcont: Measures the association between a categorical variable and a...

In GDAtools: A Toolbox for Geometric Data Analysis and More

Measures the association between a categorical variable and a continuous variable

Description

Measures the association between a categorical variable and a continuous variable

Usage

assoc.catcont(x,y,weights=rep(1,length(x)),
              nperm=NULL,distrib="asympt",digits=3)

Arguments

x	the categorical variable (must be a factor)
y	the continuous variable (must be a numeric vector)
weights	an optional numeric vector of weights (by default, a vector of 1 for uniform weights)
nperm	numeric. Number of permutations for the permutation test of independence. If NULL (default), no permutation test is performed.
distrib	the null distribution of permutation test of independence can be approximated by its asymptotic distribution ("asympt", default) or via Monte Carlo resampling ("approx".
digits	integer. The number of digits (default is 3).

Value

A list with the following elements :

eta.squared	eta-squared between the two variables
permutation.pvalue	p-value from a permutation (so non-parametric) test of independence
cor	point biserial correlation between the two variables, for each level of the categorical variable
cor.perm.pval	permutation p-value of the correlation between the two variables, for each level of the categorical variable

Author(s)

Nicolas Robette

References

Rakotomalala R., 'Comprendre la taille d'effet (effect size)', [http://eric.univ-lyon2.fr/~ricco/cours/slides/effect_size.pdf]

See Also

assoc.twocat, assoc.twocont, assoc.yx, condesc, catdesc, darma, ggassoc_boxplot

Examples

## Annette Dobson (1990) "An Introduction to Generalized Linear Models".
## Page 9: Plant Weight Data.
ctl <- c(4.17,5.58,5.18,6.11,4.50,4.61,5.17,4.53,5.33,5.14)
trt <- c(4.81,4.17,4.41,3.59,5.87,3.83,6.03,4.89,4.32,4.69)
group <- gl(2, 10, 20, labels = c("Ctl","Trt"))
weight <- c(ctl, trt)
assoc.catcont(group,weight,nperm=100)

GDAtools documentation built on March 18, 2022, 5:13 p.m.