Heterozygosity: Heterozygosity Rate

In GenoPop: Genotype Imputation and Population Genomics Efficiently from Variant Call Formatted (VCF) Files

Heterozygosity Rate

Description

This function calculates the rate of heterozygosity for samples in a VCF file. (The proportion of heterozygote genotypes.) For batch processing, it uses process_vcf_in_batches. For windowed analysis, it uses a similar approach tailored to process specific genomic windows (process_vcf_in_windows).

Usage

Heterozygosity(
  vcf_path,
  batch_size = 10000,
  threads = 1,
  write_log = FALSE,
  logfile = "log.txt",
  window_size = NULL,
  skip_size = NULL,
  exclude_ind = NULL
)

Arguments

vcf_path	Path to the VCF file.
batch_size	The number of variants to be processed in each batch (used in batch mode only, default of 10,000 should be suitable for most use cases).
threads	Number of threads to use for parallel processing.
write_log	Logical, indicating whether to write progress logs.
logfile	Path to the log file where progress will be logged.
window_size	Size of the window for windowed analysis in base pairs (optional). When specified, skip_size must also be provided.
skip_size	Number of base pairs to skip between windows (optional). Used in conjunction with window_size for windowed analysis.
exclude_ind	Optional vector of individual IDs to exclude from the analysis. If provided, the function will remove these individuals from the genotype matrix before applying the custom function. Default is NULL, meaning no individuals are excluded.

Value

In batch mode (no window_size or skip_size provided): Observed heterozygosity rate averaged over all loci. In window mode (window_size and skip_size provided): A data frame with columns 'Chromosome', 'Start', 'End', and 'Ho', representing the observed heterozygosity rate within each window.

Examples

vcf_file <- system.file("tests/testthat/sim.vcf.gz", package = "GenoPop")
index_file <- system.file("tests/testthat/sim.vcf.gz.tbi", package = "GenoPop")
# Batch mode example
Ho <- Heterozygosity(vcf_file)
# Window mode example
Ho_windows <- Heterozygosity(vcf_file, window_size = 100000, skip_size = 50000)

GenoPop documentation built on April 3, 2025, 9:51 p.m.