crosstab {ecodist}R Documentation

Data formatting

Description

Converts field data of the form site, species, observation into a matrix.

Usage

crosstab(rowlab, collab, values, type = "sum", allrows, allcols)

Arguments

rowlab row labels, e.g. site names.
collab column labels, e.g. species names.
values data values.
type function to use to combine data, one of "sum" (default), "min", "max", "mean".
allrows optional, list of desired row names that may not appear in rowlab.
allcols optional, list of desired column names that may not appear in collab.

Details

Field data are often recorded as a separate row for each site-species combination. This function turns them into a matrix for further analysis based on unique row and column labels.

The three vectors should all be the same length (including duplicates).

If allrows or allcols exists, rows and/or columns of zeros are inserted for any elements of allrows/allcols not present in rowlab/collab.

Value

matrix with rowlab as row headings, collab as columns, and values as the data.

Author(s)

Sarah Goslee, Sarah.Goslee@ars.usda.gov

Examples

# Make a random example
plotnames <- sort(rep(1:5, 3))
speciesnames <- rep(c("A", "B", "C"), 5)
freqdata <- runif(15)

data.m <- crosstab(plotnames, speciesnames, freqdata)

[Package ecodist version 1.2.2 Index]