BWA INDEX

Creates a BWA index. For more information about BWA see BWA documentation.

Example

This wrapper can be used in the following way:

rule bwa_index:
    input:
        "{genome}.fasta",
    output:
        idx=multiext("{genome}", ".amb", ".ann", ".bwt", ".pac", ".sa"),
    log:
        "logs/bwa_index/{genome}.log",
    params:
        algorithm="bwtsw",
    wrapper:
        "v2.6.0/bio/bwa/index"

Note that input, output and log file paths can be chosen freely.

When running with

snakemake --use-conda

the software dependencies will be automatically deployed into an isolated environment before execution.

Software dependencies

• bwa=0.7.17

Authors

• Patrik Smeds

Code

__author__ = "Patrik Smeds"
__copyright__ = "Copyright 2016, Patrik Smeds"
__email__ = "patrik.smeds@gmail.com"
__license__ = "MIT"

from os.path import splitext

from snakemake.shell import shell

log = snakemake.log_fmt_shell(stdout=False, stderr=True)

# Check inputs/arguments.
if len(snakemake.input) == 0:
    raise ValueError("A reference genome has to be provided!")
elif len(snakemake.input) > 1:
    raise ValueError("Only one reference genome can be inputed!")

# Prefix that should be used for the database
prefix = snakemake.params.get("prefix", splitext(snakemake.output.idx[0])[0])

if len(prefix) > 0:
    prefix = "-p " + prefix

# Contrunction algorithm that will be used to build the database, default is bwtsw
construction_algorithm = snakemake.params.get("algorithm", "")

if len(construction_algorithm) != 0:
    construction_algorithm = "-a " + construction_algorithm

shell(
    "bwa index" " {prefix}" " {construction_algorithm}" " {snakemake.input[0]}" " {log}"
)