Computes the p-value for LR.suspect

Description

It is difficult to obtain accurate p-values based on simulation. This function provides an exact alternative.

Usage

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pvalue.machine(LR.suspect, LR.table, P.table)

Arguments

LR.suspect

Numeric. Observed likeliood ratio (1x1 positive value)

LR.table

Pre-computed likelihood ratios for every genotype of every marker (MxG matrix). Each row corresponds to a marker. G is the maximum number of genotypes for any marker. Markers with fewer than G genotypes must have 0 in redundant columns

P.table

The population probabilities for every genotype of every marker (MxG matrix). Must corresponds to the genotypes in LR.table. See description of LR.table

Value

The p-value, where a value close to 0 indicates that the suspect is a contributor.

Author(s)

Dorum, Bleka, Snipen <guro.dorum@nmbu.no>

See Also

The function is obsolete.

See dists.product and dists.product.pair for efficient computation of likelihood ratio distributions.

Examples

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#Simple example, 2 markers, 3 genotypes. LR's and genotype probabilities precalculated
#The LR's for all possible genotypes for both markers. Each row corresponds to a marker
LR.table <- matrix(c(6,5,5,4,3,2),2,3)
#The population probabilities corresponding to the genotypes in LR.table
P.table <- rbind(c(0.2, 0.4, 0.4), c(0.1,0.6,0.3))
#LR observed for suspect
LR.suspect <- 20
pvalue <- pvalue.machine(LR.suspect, LR.table, P.table)
cat("p-value = ", pvalue, "\n")