qra-package: qra: A package for calculations that relate to...

Description Details qra functions Author(s)


The qra package provides the functions: checkDisp, getRho, extractLT, getScaleCoef, scaleLocAdjust, fieller, gpsWithin, varRatio, foldp, graphSum, fpower


The three vignettes provide examples of the use of the functions.

qra functions

fieller: Calculates lethal dose estimates, using Fieller's formula to calculate 95 of the functions noted below are useful ancillaries to fieller and fieller2, notably foldp, fpower, extractLT, and getScaleCoef.

fieller2: Use when a folded power link has been used. See fpower.

extractLT: Obtains complete set of LT or LD estimate, when it is convenient to get results from several models at the same time.

foldp: Calculates the ratio of p+eps to 1-code+eps

getRho Extracts estimates of the intra-class correlation from a glmmTMB model object with betabinomial error. See the vignette [timeMortality] for details of the parametization used for the betabinomial error.

getScaleCoef: Extracts the scale coefficients from a vector that has been scaled using scale, as needed so that the scaling can be undone.

gpsWithin Renumbers group identifiers so that they run from 1 to number of groups within for each level of the specified factor.

scaleLocAdjust: Returns, for glmmTMB models with a betabinomial error, dispersion factors (i.e., multipliers for the binomial variance) as functions of predicted values.

varRatio: Returns a first order approximation to the variance of the $y$-ordinate to slope ratio. This is used in the type="Delta" approximation, for calculation of LT and LD confidence intervals. Primarily, this is provided for purposes of comparison, to make it easy to show how poor the approximation can be, and to warn against its general dewvuse!


Maintainer: John Maindonald john@statsresearch.co.nz (ORCID)

qra documentation built on Oct. 29, 2021, 9:06 a.m.