easyCODA (version 0.28)

CA: Correspondence analysis

Description

Computation of correspondence analysis on a table of nonnegative data.

Usage

CA(data, nd = 2, suprow = NA, supcol = NA)

Arguments

data

A data frame or matrix of nonnegative data (no negative values)

nd

Number of dimensions for summary solution if not 2 (default)

suprow

Indices of rows that are supplementary points

supcol

Indices of columns that are supplementary points

Value

sv

Singular values

nd

Number of dimensions in solution results

rownames

Row names

rowmass

Row weights

rowdist

Row logratio distances to centroid

rowinertia

Row inertias

rowcoord

Row standard coordinates

rowpcoord

Row principal coordinates

rowsup

Indices of row supplementary points

colnames

Column names

colmass

Column weights

coldist

Column logratio distances to centroid

colinertia

Column inertias

colcoord

Column standard coordinates

colpcoord

Column principal coordinates

N

The compositional data table

Details

The function CA is a simple wrapper for the ca function in the ca package (Nenadic and Greenacre, 2007), for compatibility within the easyCODA package.

Supplementary rows and columns can be declared (also known as passive points) -- these do not contribute to the solution but are positioned on the solution axes.

The function borrows the structure and functions of the ca package, which is required, and produces a ca object, and the same print, summary and plot methods can be used, as for a ca object. It additionally exports the principal coordinates of both the rows and columns, not presently found in the ca package.

References

Nenadic, O. and Greenacre, M. (2007). Correspondence analysis in R, with two- and three-dimensional graphics: The ca package. Journal of Statistical Software, 20 (3), http://www.jstatsoft.org/v20/i03/

See Also

PLOT.CA, plot.ca, summary.ca, print.ca

Examples

# NOT RUN {
# (weighted) LRA of the RomanCups data set, showing default symmetric map
data(cups)
PLOT.CA(CA(cups))

data(author)
ca(author)
plot(CA(author))      # ca plot function
PLOT.CA(CA(author))   # easyCODA plot function
# }