rgr (version 1.1.15)

alts2dups: Create a Matrix of Duplicate Pairs from Sequential Data

Description

Function to take data stored as stacked records or alternating rows of records for ndup duplicate pairs and generate a matrix with ndup rows and two columns for the duplicate data, for further details see x in Arguments below. The function returns a matrix for processing.

Usage

alts2dups(x, ifalt = FALSE)

Arguments

x

a column vector from a matrix or data frame, x[1], ..., x[2*n]. The default is that the first n members of the vector are the first measurements and the second n members are the duplicate measurements. If the measurements alternate, i.e. duplicate pair 1 measurement 1 followed by measurement 2, etc., set ifalt = TRUE.

ifalt

set ifalt = TRUE to accommodate alternating sets of paired observations.

Value

xx

a ndup by 2 matrix containing the duplicate pairs. Row names are sequenced 1:ndup and the two column names are generated from the input variable name, x with .1 or .2 appended, respectively.

Details

Function provides an easy procedure with function plot to present duplicate data as an x-y plot. The matrix generated can be passed directly to plot in its call and the matrix column headings synthesized from the input variable name are used as plot axis titles.

Examples

# NOT RUN {
## Make test data available
data(ad.test)
attach(ad.test)

## Save matrix of duplicate pairs
test.save <- alts2dups(Cu, ifalt = TRUE)

## Plot analytical duplicate analyses
plot(alts2dups(Cu, ifalt = TRUE), log = "xy")

## Clean-up and detach test data
rm(test.save)
detach(ad.test)
# }