plot_precision_fan_chart

Plots the proportion of simulations in which the posterior credible
interval width is less than or equal to a target, as a function of
sample size n. Optionally colours separate curves by an effect-grid
variable.

Provides tools for Bayesian power analysis and assurance calculations using the statistical frameworks of 'brms' and 'INLA'. Includes simulation-based approaches, support for multiple decision rules (direction, threshold, ROPE), sequential designs, and visualisation helpers. Methods are based on Kruschke (2014, ISBN:9780124058880) "Doing Bayesian Data Analysis: A Tutorial with R, JAGS, and Stan", O'Hagan & Stevens (2001) <doi:10.1177/0272989X0102100307> "Bayesian Assessment of Sample Size for Clinical Trials of Cost-Effectiveness", Kruschke (2018) <doi:10.1177/2515245918771304> "Rejecting or Accepting Parameter Values in Bayesian Estimation", Rue et al. (2009) <doi:10.1111/j.1467-9868.2008.00700.x> "Approximate Bayesian inference for latent Gaussian models by using integrated nested Laplace approximations", and Bürkner (2017) <doi:10.18637/jss.v080.i01> "brms: An R Package for Bayesian Multilevel Models using Stan".

Tony Myers

powerbrmsINLA

Bayesian Power Analysis Using 'brms' and 'INLA'

plot_precision_fan_chart function

<dl><dt>power_results</dt>
<dd>Output from a <code>brms_inla_power*</code> function, or a
data.frame with at least columns <code>n</code> and <code>ci_width</code>, plus any
effect-grid columns (e.g. <code>treatment</code>, <code>age_effect</code>).</dd>
<dt>ci_width_target</dt>
<dd>Numeric, target width for the credible interval.
Assurance is defined as Pr(ci_width &lt;= ci_width_target).</dd>
<dt>effect_filter</dt>
<dd>Optional named list for filtering effect-grid
columns, e.g. <code>list(treatment = 0.3)</code>.</dd>
<dt>colour_by</dt>
<dd>Optional name of an effect-grid column to colour
separate curves by. If <code>NULL</code>, only n is used.</dd>
<dt>title, subtitle</dt>
<dd>Optional plot labels.</dd></dl>

Arguments

Precision assurance as a function of sample size — plot_precision_fan_chart

<dl>

<dt>power_results</dt>
<dd>Output from a <code>brms_inla_power*</code> function, or a
data.frame with at least columns <code>n</code> and <code>ci_width</code>, plus any
effect-grid columns (e.g. <code>treatment</code>, <code>age_effect</code>).</dd>


<dt>ci_width_target</dt>
<dd>Numeric, target width for the credible interval.
Assurance is defined as Pr(ci_width &lt;= ci_width_target).</dd>


<dt>effect_filter</dt>
<dd>Optional named list for filtering effect-grid
columns, e.g. <code>list(treatment = 0.3)</code>.</dd>


<dt>colour_by</dt>
<dd>Optional name of an effect-grid column to colour
separate curves by. If <code>NULL</code>, only n is used.</dd>


<dt>title, subtitle</dt>
<dd>Optional plot labels.</dd>

</dl>

plot_precision_fan_chart: Precision assurance as a function of sample size

Description

Usage

Value

Arguments

Details