gtrack.import: Creates a track from WIG / BigWig / BedGraph / BED / tab-delimited file

Description

Creates a track from WIG / BigWig / BedGraph / BED / tab-delimited file

Usage

gtrack.import(
  track = NULL,
  description = NULL,
  file = NULL,
  binsize = NULL,
  defval = NaN,
  attrs = NULL
)

Value

None.

Arguments

track: track name
description: a character string description
file: file path
binsize: bin size of the newly created 'Dense' track or '0' for a 'Sparse' track
defval: default track value
attrs: a named vector or list of attributes to be set on the track after import

Details

This function creates a track from WIG / BigWig / BedGraph / tab-delimited file. Zipped files are supported (file name must have '.gz' or '.zip' suffix).

Tab-delimited files must start with a header line with the following column names (tab-separated): 'chrom', 'start', 'end', and exactly one value column name (e.g. 'value'). Each subsequent line provides a single interval: - chrom: chromosome name (e.g. 'chr1') - start: 0-based start coordinate (inclusive) - end: 0-based end coordinate (exclusive) - value: numeric value (floating point allowed); exactly one value column is supported

Columns must be separated by tabs. Coordinates must refer to chromosomes existing in the current genome. Missing values can be specified as 'NaN'.

BED files (.bed/.bed.gz/.bed.zip) are also supported. If the BED 'score' column (5th column) exists and is numeric, it is used as the interval value; otherwise a constant value of 1 is used. For BED inputs, 'binsize' controls the output type: if 'binsize' is 0 the track is 'Sparse'; otherwise the track is 'Dense' with bin-averaged values based on overlaps with BED intervals (and 'defval' for regions not covered).

If 'binsize' is 0 the resulted track is created in 'Sparse' format. Otherwise the 'Dense' format is chosen with a bin size equal to 'binsize'. The values that were not defined in input file file are substituted by 'defval' value.

'description' is added as a track attribute.

Examples

Run this code

# \dontshow{
options(gmax.processes = 2)
# }

# \donttest{
gdb.init_examples()

# Create a simple WIG file for demonstration
temp_file <- tempfile(fileext = ".wig")
writeLines(c(
    "track type=wiggle_0 name=\"example track\"",
    "fixedStep chrom=chr1 start=1 step=1",
    "1.5",
    "2.0",
    "1.8",
    "3.2"
), temp_file)

# Basic import
gtrack.import("example_track", "Example track from WIG file",
    temp_file,
    binsize = 1
)
gtrack.info("example_track")
gtrack.rm("example_track", force = TRUE)

# Import with custom attributes
attrs <- c("author" = "researcher", "version" = "1.0", "experiment" = "test")
gtrack.import("example_track_with_attrs", "Example track with attributes",
    temp_file,
    binsize = 1, attrs = attrs
)

# Check that attributes were set
gtrack.attr.get("example_track_with_attrs", "author")
gtrack.attr.get("example_track_with_attrs", "version")
gtrack.attr.get("example_track_with_attrs", "experiment")

# Clean up
gtrack.rm("example_track_with_attrs", force = TRUE)
# }