R: Calculate Band-Sharing Dissimilarity Between Genotypes

Lynch.distance {polysat} | R Documentation

## Calculate Band-Sharing Dissimilarity Between Genotypes

### Description

Given two genotypes in the form of vectors of unique alleles, a dissimilarity is calculated as: 1 - (number of alleles in common)/(average number of alleles per genotype).

### Usage

    Lynch.distance(genotype1, genotype2, usatnt = NA, missing = -9)

### Arguments

`genotype1` | A vector containing all alleles for a particular sample and locus. Each allele is only present once in the vector.
`genotype2` | A vector of the same form as `genotype1`, for another sample at the same locus.
`usatnt` | The microsatellite repeat length for this locus (ignored by the function).
`missing` | The symbol used to indicate missing data in either genotype vector.

### Details

Lynch (1990) defines a simple measure of similarity between DNA fingerprints. This is 2 times the number of bands that two fingerprints have in common, divided by the total number of bands that the two genotypes have. `Lynch.distance` returns a dissimilarity, which is 1 minus the similarity.

### Value

If the first element of either or both input genotypes is equal to `missing`, NA is returned.

Otherwise, a numerical value is returned. This is one minus the similarity. The similarity is calculated as the number of alleles that the two genotypes have in common divided by the mean length of the two genotypes.

### Author(s)

Lindsay V. Clark

### References

Lynch, M. (1990) The similarity index and DNA fingerprinting. Molecular Biology and Evolution 7, 478-484.

### See Also

`Bruvo.distance`, `meandistance.matrix`

### Examples

    Lynch.distance(c(100,102,104), c(100,104,108))
    Lynch.distance(-9, c(102,104,110))
    Lynch.distance(c(100), c(100,104,106))

[Package polysat version 1.7-6 Index]