tef_link_weibull: Construct a weibull link function parameterized with...

In akcochrane/TEfits: Time-evolving model fits

Construct a weibull link function parameterized with threshold and bias

Description

Function is under development and is likely to be buggy, and to change frequently.

Usage

tef_link_weibull(
  changeForm,
  linkX,
  threshVal = 0.75,
  rhAsymptote = 1,
  yIntercept = 0.5,
  lapseRate = 0.005,
  boundScale = 2,
  constantPar_prior = "normal(0,3)"
)

Arguments

changeForm	The formula describing the change in threshold
linkX	Character. The name of the "x" variable in the weibull link function (e.g., stimulus strength in a psychometric function). Should be a positive real numeric variable (e.g., presentation time or number of targets).
threshVal	The threshold at which to evaluate the weibull function (i.e., the y-value for which threshold describes the x-value).
rhAsymptote	The asymptotic value of the weibull function with large linkX values (e.g., accuracy at infinitely large stimulus strength).
yIntercept	The origin value of the weibull function (with a linkX value of zero, e.g., accuracy at a stimulus strength of zero; in behavioral data is likely to be "guessing rate").
lapseRate	The offset, from rhAsymptote, of the weibull function at arbitrarily large values of linkX. A small lapse rate improves model fit (see Wichmann and Hill, 2001, P&P).
boundScale	Currently not implemented. Upper threshold of threshold estimates, as a multiple of the maximum absolute linkX.
constantPar_prior	The prior to put on the constant component of the weibull function (i.e., shape parameter). Only relevant if passing the model to a brm model (e.g., with TEbrm).

Details

shape is a parameter in the weibull function, and must not be used as a name of data variables (e.g., linkX or within changeForm).

Examples

equation_to_fit <- tef_link_weibull( tef_change_expo3('trialNum', parForm = ~ (1|subID)) , linkX = 'absoluteRatio' )

akcochrane/TEfits documentation built on June 12, 2025, 11:10 a.m.