imageData (version 0.1-61)

splitContGRdiff: Adds the growth rates calculated continuously over time for subsets of a response to a data.frame

Description

Uses AGRdiff, PGR and RGRdiff to calculate growth rates continuously over time for a subset of the values of response and stores the results in data. The subsets are those values with the same levels combinations of the factors listed in INDICES.

Usage

splitContGRdiff(data, responses, INDICES,
                which.rates = c("AGR","PGR","RGR"), suffices.rates=NULL, 
                times.factor = "Days")

Value

A data.frame containing data to which has been added a column for the differences between the times.factor, if it is not already in data, and columns with growth rates. The name of the column for times.factor

differences will be the times.factor with ".diff" appended and, for each of the growth-rate columns will be the value of response with one of ".AGR", ".PGR"

or "RGR" or the corresponding value from suffices.GR

appended.

Arguments

data

A data.frame containing the columns for which growth rates are to be calculated.

responses

A character giving the names of the columns in data for which growth rates are to be calculated.

INDICES

A character giving the name(s) of the factor(s) that define the subsets of response for which growth rates are to be calculated continuously. If the columns corresponding to INDICES are not factor(s) then they will be coerced to factor(s). The subsets are formed using by.

which.rates

A character giving the growth rates that are to be calculated. It should be a combination "AGR", "PGR" and "RGR".

times.factor

A character giving the name of the column in data containing the factor for times at which the data was collected. Its levels will be used in calculating growth rates and should be numeric values stored as characters.

suffices.rates

A character giving the characters to be appended to the names of the responses to provide the names of the columns containing the calculated growth rates. The order of the suffices in suffices.rates should correspond to the order of the elements of which.rates. If NULL, the values of which.rates are used.

Author

Chris Brien

See Also

fitSpline, splitSplines

Examples

data(exampleData)
longi.dat <- splitContGRdiff(longi.dat, response="Area.smooth", 
                             INDICES = "Snapshot.ID.Tag", which.rates=c("AGR", "RGR"))