compute_loss {fangs}

Compute the FARO Loss Between Feature Allocations

Description

The FARO loss is computed between two feature allocations, each represented in binary matrix form.

Usage

compute_loss(Z1, Z2, a = 1, augmented = FALSE)

Arguments

Z1

A feature allocation in binary matrix form, with items in the rows and features in the columns.

Z2

A feature allocation in binary matrix form, with items in the rows and features in the columns.

a

A numeric scalar for the cost parameter of generalized Hamming distance used in FARO loss. The other cost parameter, b, is equal to 2 - a.

augmented

If TRUE, the column permutation (used by FARO loss to compare the feature allocations) is returned for each matrix.

Value

The FARO loss as a scalar value if augmented = FALSE, otherwise, a list of 3 elements including the loss and the two column permutations.

References

D. B. Dahl, D. J. Johnson, R. J. Andros (2023+), Comparison and Bayesian Estimation of Feature Allocations, Journal of Computational and Graphical Statistics, doi:10.1080/10618600.2023.2204136.

Examples

Z1 <- matrix(c(0,1,1,0,1,1,0,1,1,1,1,1), byrow=TRUE, nrow=6)
Z2 <- matrix(c(0,0,1,0,0,0,0,0,0,0,0,0,1,1,1,0,1,0), byrow=TRUE, nrow=6)
compute_loss(Z1,Z2)
x <- compute_loss(Z1,Z2,a=1,TRUE)
sum(cbind(Z1,0) != Z2)
sum(cbind(Z1,0)[,x$permutation1] != Z2)
sum(cbind(Z1,0) != Z2[,x$permutation2])