ream1.0-3 package

Density, Distribution, and Sampling Functions for Evidence Accumulation Models

CDSTP

Continuous Dual-Stage Two-Phase Model of Selective Attention

CSTM_T

Custom Time-Dependent Drift Diffusion Model

CSTM_TW

Custom Time- and Weight-Dependent Drift Diffusion Model

CSTM_TX

Custom Time- and Evidence-Dependent Drift Diffusion Model

dCDSTP_grid

Generate Grid for PDF of the Continuous Dual-Stage Two-Phase Model of ...

dCSTM_T_grid

Generate Grid for PDF of Custom Time-Dependent Drift Diffusion Model

dCSTM_TW_grid

Generate Grid for PDF of Custom Time- and Weight-Dependent Drift Diffu...

dCSTM_TX_grid

Generate Grid for PDF of Custom Time- and Evidence-Dependent Drift Dif...

dDMC_grid

Generate Grid for PDF of Diffusion Model of Conflict Tasks

dETM_grid

Generate Grid for PDF of the Exponential Threshold Model

dLIM_grid

Generate Grid for PDF of the Leaky Integration Model

dLIMF_grid

Generate Grid for PDF of the Leaky Integration Model With Flip

dLTM_grid

Generate Grid for PDF of the Linear Threshold Model

DMC

Diffusion Model for Conflict Tasks

dPAM_grid

Generate Grid for PDF of Piecewise Attention Model

dRDMC_grid

Generate Grid for PDF of the Revised Diffusion Model of Conflict Tasks

dRTM_grid

Generate Grid for PDF of the Rational Threshold Model

dSDDM_grid

Generate Grid for PDF of the Simple Drift Diffusion Model

dSDPM_grid

Generate Grid for PDF of the Sequential Dual Process Model

dSSP_grid

Generate Grid for PDF of the Shrinking Spotlight Model

dUGM_grid

Generate Grid for PDF of the Urgency Gating Model

dUGMF_grid

Generate Grid for PDF of the Urgency Gating Model With Flip

dWDSTP_grid

Generate Grid for PDF of the Weibull Dual-Stage Two-Phase Model of Sel...

dWTM_grid

Generate Grid for PDF of the Weibull Threshold Model

ETM

Exponential Threshold Model

LIM

Leaky Integration Model

LIMF

Leaky Integration Model With Flip

LTM

Linear Threshold Model

PAM

Piecewise Attention Model

RDMC

Revised Diffusion Model of Conflict Tasks

RTM

Rational Threshold Model

SDDM

Simple Drift Diffusion Model

SDPM

Sequential Dual Process Model

SSP

Shrinking Spotlight Model

UGM

Urgency Gating Model

UGMF

Urgency Gating Model With Flip

WDSTP

Weibull Dual-Stage Two-Phase Model of Selective Attention

WTM

Weibull Threshold Model

Calculate the probability density functions (PDFs) for two threshold evidence accumulation models (EAMs). These are defined using the following Stochastic Differential Equation (SDE), dx(t) = v(x(t),t)*dt+D(x(t),t)*dW, where x(t) is the accumulated evidence at time t, v(x(t),t) is the drift rate, D(x(t),t) is the noise scale, and W is the standard Wiener process. The boundary conditions of this process are the upper and lower decision thresholds, represented by b_u(t) and b_l(t), respectively. Upper threshold b_u(t) > 0, while lower threshold b_l(t) < 0. The initial condition of this process x(0) = z where b_l(t) < z < b_u(t). We represent this as the relative start point w = z/(b_u(0)-b_l(0)), defined as a ratio of the initial threshold location. This package generates the PDF using the same approach as the 'python' package it is based upon, 'PyBEAM' by Murrow and Holmes (2023) <doi:10.3758/s13428-023-02162-w>. First, it converts the SDE model into the forwards Fokker-Planck equation dp(x,t)/dt = d(v(x,t)*p(x,t))/dt-0.5*d^2(D(x,t)^2*p(x,t))/dx^2, then solves this equation using the Crank-Nicolson method to determine p(x,t). Finally, it calculates the flux at the decision thresholds, f_i(t) = 0.5*d(D(x,t)^2*p(x,t))/dx evaluated at x = b_i(t), where i is the relevant decision threshold, either upper (i = u) or lower (i = l). The flux at each thresholds f_i(t) is the PDF for each threshold, specifically its PDF. We discuss further details of this approach in this package and 'PyBEAM' publications. Additionally, one can calculate the cumulative distribution functions of and sampling from the EAMs.

  • Maintainer: Raphael Hartmann
  • License: GPL (>= 2)
  • Last published: 2024-09-17