Aggregate multiple <epiparameter> objects into a single <epiparameter> object. — aggregate.multi

Combine a list of <epiparameter> objects into a single <epiparameter> with a mixture distribution [see distributional::dist_mixture()].

The aggregated <epiparameter> returned from aggregate() can then be used with the density(), cdf(), quantile() and generate() methods for the combined distributions.

Usage

# S3 method for class 'multi_epiparameter'
aggregate(x, weighting = c("equal", "sample_size", "custom"), ..., weights)

Arguments

x: A <multi_epiparameter> object.
weighting: A character string with the type of weighting to use to create the mixture distribution. Options are: "equal" for equal weighting across distributions, "sample_size" for using the sample size in each <epiparameter> object to weight the distribution (the sample sizes are normalised), or "custom" allows a vector of weights to be passed to the weights argument for a custom weighting.
...: dots Not used, will warn if extra arguments are passed to function.
weights: A numeric vector of equal length the number of <epiparameter> objects passed to x. weights is only required if weighting = "custom".

Value

An <epiparameter> object

Details

The aggregate() method requires that all <epiparameter> objects are parameterised with <distribution> objects (from the distributional package). This means that unparameterised (see is_parameterised()) or discretised (see discretise()) distributions cannot be aggregated and the function will error.

Examples

ebola_si <- epiparameter_db(epi_name = "serial interval", disease = "ebola")
#> Returning 4 results that match the criteria (4 are parameterised). 
#> Use subset to filter by entry variables or single_epiparameter to return a single entry. 
#> To retrieve the citation for each use the 'get_citation' function
aggregate(ebola_si)
#> Disease: Ebola Virus Disease
#> Pathogen: Ebola Virus
#> Epi Parameter: serial interval
#> Study: WHO Ebola Response Team, Agua-Agum J, Ariyarajah A, Aylward B, Blake I,
#> Brennan R, Cori A, Donnelly C, Dorigatti I, Dye C, Eckmanns T, Ferguson
#> N, Formenty P, Fraser C, Garcia E, Garske T, Hinsley W, Holmes D,
#> Hugonnet S, Iyengar S, Jombart T, Krishnan R, Meijers S, Mills H,
#> Mohamed Y, Nedjati-Gilani G, Newton E, Nouvellet P, Pelletier L,
#> Perkins D, Riley S, Sagrado M, Schnitzler J, Schumacher D, Shah A, Van
#> Kerkhove M, Varsaneux O, Kannangarage N (2015). “West African Ebola
#> Epidemic after One Year — Slowing but Not Yet under Control.” _The New
#> England Journal of Medicine_. doi:10.1056/NEJMc1414992
#> <https://doi.org/10.1056/NEJMc1414992>.
#> Distribution: mixture: gamma, gamma, gamma, gamma (days)
#> Distribution: mixture: gamma, gamma, gamma, gamma (days)
#> Distribution: mixture: gamma, gamma, gamma, gamma (days)
#> Distribution: mixture: gamma, gamma, gamma, gamma (days)
#> Parameters:
#>   dist.shape: 2.188
#>   dist.rate: 0.154
#>   dist.shape: 4.903
#>   dist.rate: 0.316
#>   dist.shape: 2.068
#>   dist.rate: 0.137
#>   dist.shape: 1.898
#>   dist.rate: 0.153
#>   w1: 0.250
#>   w2: 0.250
#>   w3: 0.250
#>   w4: 0.250