birchObj {birch}R Documentation

A birch object for demonstration purposes

Description

A birch object created from simulated data for the purposes of demonstration

Usage

data(birchObj)

Format

A birch object with 318 subclusters. The object contains a list of

sumXi
a numeric matrix containing the column sum of the observations in each subcluster.
sumXisq
a numeric array containing the sum-of-squares of the observations in each subcluster.
N
a numeric vector containing the number of observations in each subcluster.
members
a list, each element of which contains a vector of the observations numbers present in that subcluster.

Details

This birch object was created from a simulated data set of two multivariate normals. Its primary use is for demonstrating functions in the help files. The sequence of commands for creating the object was as follows:

    library(MASS) ## for mvrnorm
    library(birch)

    ## Create data set
    set.seed(1234) 
    x <- mvrnorm(1.5e5, mu=rep(0,5), Sigma=diag(1,5))
    x <- rbind(x, mvrnorm(1e5, mu=rep(10,5),
                          Sigma=diag(0.1,5)+0.9))

    ## Create birch object, and save it
    birchObj <- birch(x, 5)
    save(birchObj, file="birchObj.rda")

References

Harrington, J and Salibian-Barrera, M (2007) “Finding Approximate Solutions to Combinatorial Problems with Very Large Datasets using BIRCH”, submitted to Statistical Algorithms and Software, 2nd Special Issue Computational Statistics and Data Analysis. http://www.stat.ubc.ca/~harringt/birch.pdf.

Harrington, J and Salibian-Barrera, M (2008) “birch: Working with very large data sets”, submitted to Journal of Statistical Software. http://www.stat.ubc.ca/~harringt/birch-jss.pdf.

Examples

data(birchObj)

[Package birch version 1.1-3 Index]