score {LogitBoost}R Documentation

Computes the score function of gene expression vectors

Description

The score function measures how well an explanatory variable discriminates a given binary response. It can be interpreted as counting for each observation having response zero, the number of individuals of response class one that have smaller expression values, and summing up these quantities and is equivalent to the test statistic of the Wilcoxon test.

Usage

score(x, resp)

Arguments

x A numerical vector, containing the value of the explanatory variable for all instances.
resp Vector, containing the class labels of the instances which have to coded by 0 and 1.

Value

An integer, the score of that particular explanatory variable.

Author(s)

Marcel Dettling

References

See "Boosting for Tumor Classification with Gene Expression Data", Dettling and Buhlmann (2002), available on the web page http://stat.ethz.ch/~dettling/boosting.html

Examples

data(leukemia)

plot(leukemia.x[,69],leukemia.y)
title(paste("Score = ", score(leukemia.x[,69], leukemia.y)))

[Package LogitBoost version 1.1-9 Index]