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NeuralEstimators (version 0.1.2)

sampleposterior: sampleposterior

Description

Given data Z, a neural likelihood-to-evidence-ratio estimator, and a prior, draws samples from the implied approximate posterior distribution

Currently, the sampling algorithm is based on a fine-gridding theta_grid of the parameter space. The approximate posterior density is evaluated over this grid, which is then used to draw samples. This is very effective when making inference with a small number of parameters. For models with a large number of parameters, other sampling algorithms may be needed (please feel free to contact the package maintainer for discussion).

Usage

sampleposterior(
  estimator,
  Z,
  theta_grid,
  N = 1000,
  prior = NULL,
  use_gpu = TRUE
)

Value

a p × N matrix of posterior samples, where p is the number of parameters in the model. If multiple data sets are given in Z, a list of posterior samples will be returned

Arguments

estimator

a neural likelihood-to-evidence-ratio estimator

Z

data; it's format should be amenable to the architecture of estimator

theta_grid

a (fine) gridding of the parameter space, given as a matrix with p rows, where p is the number of parameters in the model

N

number of samples to draw (default 1000)

prior

the prior (default uniform), specified as a Julia or R function

use_gpu

a boolean indicating whether to use the GPU if it is available (default true)

See Also

mlestimate(), mapestimate()