findbetaqq | R Documentation |
A function to estimate the parameters alpha and beta of a Beta distribution based on the existing prior belief (data and/or expert opinion) about the values of two distinct percentiles.
findbetaqq(percentile.value1, percentile1,
percentile.value2, percentile2, seed = 280385, nsims=10000)
percentile.value1 |
specify the value for the first percentile. It takes a value between 0 and 1. |
percentile1 |
specify which is the percentile that corresponds to percentile.value1. It takes a value between 0 and 1. |
percentile.value2 |
specify the value for the second percentile. It takes a value between 0 and 1. |
percentile2 |
specify which is the percentile that corresponds to percentile.value2. It takes a value between 0 and 1. |
seed |
A fixed seed for replication purposes. |
nsims |
Number of simulations for the creation of various summary metrics of the elicited prior. |
parameters: The beta distribution parameters Beta(a,b)
summary: A basic summary of the elicited prior
input: The initial input value that produced the above prior.
Kostoulas, P., Nielsen, S. S., Branscum, A. J., Johnson, W. O., Dendukuri, N., Dhand, N. K., Toft, N., Gardner, I. A. (2017): Reporting guidelines for diagnostic accuracy studies that use Bayesian latent class models (STARD–BLCM). Statistics in medicine, 23, 3603–3604.
## We believe that 20% of the units in an area/region have a prevalence of
## disease/infection less than or equal to 0.30 while at the same time
## we are 90% certain that the prevalence is less than 0.60
findbetaqq(
percentile.value1 = 0.30, percentile1 = 0.20,
percentile.value2 = 0.60, percentile2 = 0.90
)
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.