snpgdsVCF2GDS_R {SNPRelate} | R Documentation

## Reformat a VCF file (R implementation)

### Description

Reformat a Variant Call Format (VCF) file

### Usage

    snpgdsVCF2GDS_R(vcf.fn, out.fn, nblock=1024,
        method = c("biallelic.only", "copy.num.of.ref"),
        compress.annotation="LZMA_RA", snpfirstdim=FALSE, option = NULL,
        verbose=TRUE)

### Arguments

`vcf.fn` | the file name of VCF format, `vcf.fn` can be a vector, see details
`out.fn` | the output gds file
`nblock` | the buffer lines
`method` | either "biallelic.only" by default or "copy.num.of.ref", see details
`compress.annotation` | the compression method for the GDS variables, except "genotype"; optional values are defined in the function `add.gdsn`
`snpfirstdim` | if TRUE, genotypes are stored in the individual-major mode, (i.e, list all SNPs for the first individual, and then list all SNPs for the second individual, etc)
`option` | `NULL` or an object from `snpgdsOption`, see details
`verbose` | if TRUE, show information

### Details

GDS – Genomic Data Structures used for storing genetic array-oriented data, and the file format used in the gdsfmt package.

VCF – The Variant Call Format (VCF), which is a generic format for storing DNA polymorphism data such as SNPs, insertions, deletions and structural variants, together with rich annotations.

If there are more than one file name in `vcf.fn`, `snpgdsVCF2GDS` will merge all dataset together once they all contain the same samples. It is useful to combine genetic data if VCF data are divided by chromosomes.

`method = "biallelic.only"`: to exact bi-allelic and polymorhpic SNP data (excluding monomorphic variants); `method = "biallelic.only"`: to exact bi-allelic and polymorhpic SNP data; `method = "copy.num.of.ref"`: to extract and store dosage (0, 1, 2) of the reference allele for all variant sites, including bi-allelic SNPs, multi-allelic SNPs, indels and structural variants.

Haploid and triploid calls are allowed in the transfer, the variable `snp.id` stores the original the row index of variants, and the variable `snp.rs.id` stores the rs id.

The user could use `option` to specify the range of code for autosomes. For humans there are 22 autosomes (from 1 to 22), but dogs have 38 autosomes. Note that the default settings are used for humans. The user could call `option = snpgdsOption(autosome.end=38)` for importing the VCF file of dog. It also allows defining new chromosome coding, e.g., `option = snpgdsOption(Z=27)`, then "Z" will be replaced by the number 27.

### Value

None.

### Author(s)

Xiuwen Zheng

### References

The variant call format and VCFtools. Danecek P, Auton A, Abecasis G, Albers CA, Banks E, DePristo MA, Handsaker RE, Lunter G, Marth GT, Sherry ST, McVean G, Durbin R; 1000 Genomes Project Analysis Group. Bioinformatics. 2011 Aug 1;27(15):2156-8. Epub 2011 Jun 7.

### See Also

`snpgdsVCF2GDS_R`, `snpgdsOption`, `snpgdsBED2GDS`

### Examples

    # The VCF file
    vcf.fn <- system.file("extdata", "sequence.vcf", package="SNPRelate")
    cat(readLines(vcf.fn), sep="\n")

    snpgdsVCF2GDS_R(vcf.fn, "test1.gds", method="biallelic.only")
    snpgdsSummary("test1.gds")

    snpgdsVCF2GDS_R(vcf.fn, "test2.gds", method="biallelic.only")
    snpgdsSummary("test2.gds")

    snpgdsVCF2GDS_R(vcf.fn, "test3.gds", method="copy.num.of.ref")
    snpgdsSummary("test3.gds")

    snpgdsVCF2GDS_R(vcf.fn, "test4.gds", method="copy.num.of.ref")
    snpgdsSummary("test4.gds")

[Package SNPRelate version 1.18.1 Index]