createTargetingMatrix - Calculates a targeting rate matrix

Description

createTargetingMatrix calculates the targeting model matrix as the combined probability of mutability and substitution.

Usage

createTargetingMatrix(substitutionModel, mutabilityModel)

Arguments

substitutionModel
matrix of 5-mers substitution rates built by createSubstitutionMatrix or extendSubstitutionMatrix.
mutabilityModel
vector of 5-mers mutability rates built by createMutabilityMatrix or extendMutabilityMatrix.

Value

A matrix with the same dimensions as the input substitutionModel containing normalized targeting probabilities for each 5-mer motif with row names defining the center nucleotide and column names defining the 5-mer nucleotide sequence.

Details

Targeting rates are calculated by multiplying the normalized mutability rate by the normalized substitution rates for each individual 5-mer.

References

  1. Yaari G, et al. Models of somatic hypermutation targeting and substitution based on synonymous mutations from high-throughput immunoglobulin sequencing data. Front Immunol. 2013 4(November):358.

Examples

# Subset example data to one isotype and sample as a demo
data(ExampleDb, package="alakazam")
db <- subset(ExampleDb, ISOTYPE == "IgA" & SAMPLE == "-1h")

# Create 4x1024 models using only silent mutations
sub_model <- createSubstitutionMatrix(db, model="S")
mut_model <- createMutabilityMatrix(db, sub_model, model="S")

Warning:Insufficient number of mutations to infer some 5-mers. Filled with 0.


# Extend substitution and mutability to including Ns (5x3125 model)
sub_model <- extendSubstitutionMatrix(sub_model)
mut_model <- extendMutabilityMatrix(mut_model)

# Create targeting model from substitution and mutability
tar_model <- createTargetingMatrix(sub_model, mut_model)

See also

createSubstitutionMatrix, extendSubstitutionMatrix, createMutabilityMatrix, extendMutabilityMatrix, createTargetingModel