QE {MASSTIMATE}

Body Mass Estimates Using Combined Humeral and Femoral Circumferences

Description

This function is based on the bivariate regression equations from Campione and Evans (2012) for esimating body mass in terretrial vertebartes using the combined humeral and femoral circumferences

Usage

QE(HFC = NULL, HC, FC, equation = "raw", 
quadratic = FALSE, data = NULL, return_PI = FALSE)

Arguments

HFC

a value or vector representing the combined humeral and femoral circumferences

HC

a value or vector representing humeral circumference (in mm)

FC

a value or vector representing femoral circumference (in mm)

equation

desired estimation equation. Two possible choices (See Details)

quadratic

a logical indicating whether estimates based on the quadratic equation should be used (See Details)

data

an optional object of class = "data.frame" or class = "matrix"

return_PI

an optional logical value to also provide the wider prediction intervals on the estimate, currenly only works if equation = "raw"

Details

The function includes two different equations. equation = "raw" (default) applies the non-phylogenetically corrected regression equation - equation 1 of Campione and Evans (2012). equation = "phylocor" applies the phylogenetically corrected regression equation - equation 2 of Campione and Evans (2012).

If HFC is specified, then HC and FC are ignored.

If quadratic = TRUE, then a second set of estimates will be returned based on a quadratic view of the Campione and Evans (2012) data set (Campione, 2017).

If a data object is specified, the mass estiamtes and additional results will be added as columns to the data.frame or matrix within that object.

Value

Eight numeric values or columns are returned if quadratic = TRUE (identified by q):

log.QE

A numeric value or vector representing the mass estimate(s) in log10 grams

QE

A numeric value or vector representing the mass estimate(s) in grams

lower.QE

A numeric value or vector representing the lower prediction error derived for the specific equation by Campione and Evans (2012)

upper.QE

A numeric value or vector representing the upper prediction error

log.qQE

A numeric value or vector representing the mass estimate(s) in log10 grams using a quadratic equation

qQE

A numeric value or vector representing the mass estimate(s) in grams

lower.qQE

A numeric value or vector representing the lower prediction error derived for the specific equation by Campione (2017)

upper.qQE

A numeric value or vector representing the upper prediction error

Author(s)

Nicolas E. Campione

References

Campione, N. E. and Evans, D. C. (2012) A universal scaling relationship between body mass and proximal limb bone dimensions in quadrupedal terrestrial tetrapods. BMC Biology, 10, 60.

Campione, N. E. (2017) Extrapolation of a universal scaling relationship for estimating body masses in extinct terrestrial vertebrates. Paleobiology, 43 (4), 693-699.

See Also

cQE quadrupeds MR AHR1985 MCF2004

Examples

##Dinosaur data from Campione and Evans (2012) for quadrupedal dinosaurs
data(dinos)

##Combined equation based on the raw regression
QE(HC = dinos$HC, FC = dinos$FC, quadratic = TRUE, data = dinos, return_PI = TRUE)

##Combined equation based on the phylogenetically corrected regression, data not specified
QE(HC = dinos$HC, FC = dinos$FC, equation = "phylocor")