R: Estimate the optimal imaginary sample size for BDe(u)

alpha.star {bnlearn} | R Documentation

## Estimate the optimal imaginary sample size for BDe(u)

### Description

Estimate the optimal value of the imaginary sample size for the BDe score, assuming a uniform prior and given a network structure and a data set.

### Usage

      alpha.star(x, data, debug = FALSE)

### Arguments

`x` | an object of class `bn` (for `bn.fit` and `custom.fit`) or an object of class `bn.fit` (for `bn.net`).
`data` | a data frame containing the variables in the model.
`debug` | a boolean value. If `TRUE` a lot of debugging output is printed; otherwise the function is completely silent.

### Value

`alpha.star()` returns a positive number, the estimated optimal imaginary sample size value.

### Author(s)

Marco Scutari

### References

Steck H (2008). "Learning the Bayesian Network Structure: Dirichlet Prior versus Data". In "Proceedings of the 24th Conference on Uncertainty in Artificial Intelligence (UAI2008)", pp. 511-518.

### Examples

    data(learning.test)
    dag = hc(learning.test, score = "bic")

    for (i in 1:3) {

      a = alpha.star(dag, learning.test)
      dag = hc(learning.test, score = "bde", iss = a)

    }#FOR

[Package bnlearn version 4.3 Index]