corGraph {pcalg}R Documentation

Computing the correlation graph

Description

Computes the correlation graph. This is the graph in which an edge is drawn between node i and node j, if the null hypothesis “Correlation between X_i and X_j is zero” can be rejected on a given significance level alpha.

Usage

corGraph(dm, alpha=0.05, Cmethod="pearson")

Arguments

dm numeric matrix with rows as samples and columns as variables.
alpha significance level for correlation test (numeric)
Cmethod a character string indicating which correlation coefficient is to be used for the test. One of "pearson","kendall", or "spearman", can be abbreviated. (string)

Value

Undirected correlation graph (graph object)

Author(s)

Markus Kalisch (kalisch@stat.math.ethz.ch) and Martin Maechler

Examples

## create correlated samples
x1 <- rnorm(100)
x2 <- rnorm(100)
mat <- cbind(x1,x2, x3 = x1+x2)

## ``analyze the data''
(g <- corGraph(mat)) # a 'graphNEL' graph, undirected
plot(g) # ==> (1) and (2) are each linked to (3)

## use different significance level and different method
(g2 <- corGraph(mat, alpha=0.01, Cmethod="kendall"))
plot(g2) ## same edges as 'g'

[Package pcalg version 0.1-3 Index]