dig: Density for the Inverse Gaussian Distribution

In rettopnivek/rtclean: Outlier Removal for Response Times

Description

The density function for an inverse gaussian distribution, parameterized in terms of a one-boundary wiener process.

Usage

dig(t, kappa, xi, ln = F, summation = F)

Arguments

t	vector of response times (t > 0).
kappa	a scalar threshold value (kappa > 0).
xi	a scalar rate of evidence accumulation (xi > 0).
ln	logical; If TRUE, returns the log of the density.
summation	logical; if TRUE, returns the sum of the logs of the densities.

Details

The inverse gaussian, when parameterized in terms of brownian motion, has density

f(t) = κ/√( 2*π*t^3 ) exp( (-.5/t)*(κ - ξ*t)^2 )

where t is a response time, and κ is a threshold toward which evidence accumulates with average rate ξ and a fixed variance of 1.

Value

If ln is FALSE, gives the likelihood, else gives the log-likelihood. If both ln and summation are TRUE, gives the sum of the log-likelihoods.

rettopnivek/rtclean documentation built on May 27, 2019, 5:55 a.m.