imageData (version 0.1-61)

rcontrib: Computes a measure of how correlated each variable in a set is with the other variable, conditional on a nominated subset of them

Description

A measure of how correlated a variable is with those in a set is given by the square root of the sum of squares of the correlation coefficients between the variables and the other variables in the set (Cummings, 2007). Here, the partial correlation between the subset of the variables listed in response that are not listed in include is calculated from the partial correlation matrix for the subset, adjusting for those variables in include. This is useful for manually deciding which of the variables not in include should next be added to it.

Usage

rcontrib(responses, data, include = NULL)

Value

A numeric giving the correlation measures.

Arguments

responses

A character giving the names of the columns in data from which the correlation measure is to be calculated.

data

A data.frame containing the columns of variables from which the correlation measure is to be calculated.

include

A character giving the names of the columns in data for the variables for which other variables are to be adjusted.

Author

Chris Brien

References

Cumming, J. A. and D. A. Wood (2007) Dimension reduction via principal variables. Computational Statistics and Data Analysis, 52, 550--565.

See Also

PVA, intervalPVA

Examples

data(exampleData)
responses <- c("Area","Area.SV","Area.TV", "Image.Biomass", "Max.Height","Centre.Mass",
               "Density", "Compactness.TV", "Compactness.SV")
h <-  rcontrib(responses, longi.dat, include = "Area")