nllik {dgpsi}R Documentation

Calculate negative predicted log-likelihood


This function computes the negative predicted log-likelihood from a DGP emulator with a likelihood layer.


nllik(object, x, y)



an instance of the dgp class and it should be produced by dgp() with one of the following two settings:

  1. if struc = NULL, likelihood is not NULL;

  2. if a customized structure is provided to struc, the final layer must be likelihood layer containing only one likelihood node produced by Poisson(), Hetero(), or NegBin().


a matrix where each row is an input testing data point and each column is an input dimension.


a matrix with only one column where each row is a scalar-valued testing output data point.


See further examples and tutorials at


An updated object is returned with an additional slot named NLL that contains two elements. The first one, named meanNLL, is a scalar that gives the average negative predicted log-likelihood across all testing data points. The second one, named allNLL, is a vector that gives the negative predicted log-likelihood for each testing data point.


Any R vector detected in x and y will be treated as a column vector and automatically converted into a single-column R matrix.


## Not run: 

# Check for examples
# on how to compute the negative predicted log-likelihood
# using nllik().

## End(Not run)

[Package dgpsi version 2.1.5 Index]