# heterozygosity: Heterozygosity at a Locus Using Gene Frequencies In pegas: Population and Evolutionary Genetics Analysis System

 heterozygosity R Documentation

## Heterozygosity at a Locus Using Gene Frequencies

### Description

Thes functions compute the mean heterozygosity(ies) from gene frequencies, and return optionally the associated variance(s).

### Usage

```H(x, ...)
## S3 method for class 'loci'
H(x, variance = FALSE, observed = FALSE, ...)
## Default S3 method:
H(x, variance = FALSE, ...)

heterozygosity(x, variance = FALSE)
```

### Arguments

 `x` an object of class `"loci"`, or vector or a factor. `variance` a logical indicating whether the variance of the estimated heterozygosity should be returned (`TRUE`), the default being `FALSE`. `observed` a logical specifying whether to calculate the observed heterozygosity. `...` unused.

### Details

The argument `x` can be either a factor or a vector. If it is a factor, then it is taken to give the individual alleles in the population. If it is a numeric vector, then its values are taken to be the numbers of each allele in the population. If it is a non-numeric vector, it is a coerced as a factor.

The mean heterozygosity is estimated with:

H = n(1 - SUM (FROM i=1 TO k) p_i^2)/(n - 1)

where n is the number of genes in the sample, k is the number of alleles, and p_i is the observed (relative) frequency of the ith allele.

### Value

For the default method: a numeric vector of length one with the estimated mean heterozygosity (the default), or of length two if the variance is returned.

For the `"loci"` method: a numeric matrix with one, two, or three columns with a row for each locus and the values of heterozygosity as columns.

### References

Nei, M. (1987) Molecular evolutionary genetics. New York: Columbia University Press.

`theta.s`

### Examples

```data(jaguar)
H(jaguar, TRUE, TRUE)
## use the (old) default method:
## convert the data and compute frequencies:
S <- summary(jaguar)
## compute H for all loci:
sapply(S, function(x) H(x\$allele))
## ... and its variance
sapply(S, function(x) H(x\$allele, variance = TRUE))
```

pegas documentation built on March 7, 2023, 7:21 p.m.