Open DarioS opened 4 years ago
I'm not sure that I understand. I believe the which=
argument specifies genomic ranges to be queried, rather than ranges of the file to input. If you want to read the first 100 records, use something like
fl <- system.file("extdata", "chr7-sub.vcf.gz", package="VariantAnnotation")
vcffile <- VcfFile(fl, yieldSize = 100)
open(vcffile)
dim(readVcf(vcffile))
## read the next 100 w/ readVcf(vcffile)
## or close(vcfile)
I think the Arguments section restricts the variable type to be GRanges but the Constructor section suggests it could be one of a variety of types.
It is defined as
But, in the constructor of
ScanVcfParam
I am hoping that it's possible to import the first few records using a setting such as
which = 1:100
before importing the entire 250 GB gnomAD VCF file to check I've got what I need for an analysis.