.. _`bio/dada2/assign-taxonomy`:

DADA2_ASSIGN_TAXONOMY
=====================


.. image:: https://img.shields.io/github/issues-pr/snakemake/snakemake-wrappers/bio/dada2/assign-taxonomy?label=version%20update%20pull%20requests
   :target: https://github.com/snakemake/snakemake-wrappers/pulls?q=is%3Apr+is%3Aopen+label%3Abio/dada2/assign-taxonomy

`DADA2 <https://benjjneb.github.io/dada2/index.html>`_
Classifying sequences against a reference database using dada2 ``assignTaxonomy`` function. Optional parameters are documented in the `manual <https://www.bioconductor.org/packages/release/bioc/manuals/dada2/man/dada2.pdf#assignTaxonomy>`_ and the function is introduced in the dedicated tutorial `section <https://benjjneb.github.io/dada2/tutorial.html#assign-taxonomy>`_.



Example
-------

This wrapper can be used in the following way:

.. code-block:: python

    rule dada2_assign_taxonomy:
        input:
            seqs="results/dada2/seqTab.nochim.RDS", # Chimera-free sequence table
            refFasta="resources/example_train_set.fa.gz" # Reference FASTA for taxonomy
        output:
            "results/dada2/taxa.RDS" # Taxonomic assignments
        # Even though this is an R wrapper, use named arguments in Python syntax
        # here, to specify extra parameters. Python booleans (`arg1=True`, `arg2=False`)
        # and lists (`list_arg=[]`) are automatically converted to R.
        # For a named list as an extra named argument, use a python dict
        #   (`named_list={name1=arg1}`).
        #params:
        #    verbose=True
        log:
            "logs/dada2/assign-taxonomy/assign-taxonomy.log"
        threads: 1 # set desired number of threads here
        wrapper:
            "v3.0.1/bio/dada2/assign-taxonomy"

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

When running with

.. code-block:: bash

    snakemake --use-conda

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


Software dependencies
---------------------

* ``bioconductor-dada2=1.28.0``

Input/Output
------------
**Input:**

* ``seqs``: RDS file with the chimera-free sequence table
* ``refFasta``: A string with the path to the FASTA reference database

**Output:**

* RDS file containing the taxonomic assignments



Params
------

* ``optional arguments for ``assignTaxonomy()``, please provide them as python ``key=value`` pairs``: 




Authors
-------

* Charlie Pauvert


Code
----

.. code-block:: R

    # __author__ = "Charlie Pauvert"
    # __copyright__ = "Copyright 2020, Charlie Pauvert"
    # __email__ = "cpauvert@protonmail.com"
    # __license__ = "MIT"

    # Snakemake wrapper for classifying sequences against 
    # a reference database using dada2 assignTaxonomy function.

    # Sink the stderr and stdout to the snakemake log file
    # https://stackoverflow.com/a/48173272
    log.file<-file(snakemake@log[[1]],open="wt")
    sink(log.file)
    sink(log.file,type="message")

    library(dada2)

    # Prepare arguments (no matter the order)
    args<-list(
               seqs = readRDS(snakemake@input[["seqs"]]),
               refFasta = snakemake@input[["refFasta"]],
               multithread=snakemake@threads
               )
    # Check if extra params are passed
    if(length(snakemake@params) > 0 ){
           # Keeping only the named elements of the list for do.call()
           extra<-snakemake@params[ names(snakemake@params) != "" ]
           # Add them to the list of arguments
           args<-c(args, extra)
    } else{
        message("No optional parameters. Using default parameters from dada2::assignTaxonomy()")
    }

    # Learn errors rates for both read types
    taxa<-do.call(assignTaxonomy, args)

    # Store the taxonomic assignments as a RDS file
    saveRDS(taxa, snakemake@output[[1]],compress = T)

    # Proper syntax to close the connection for the log file
    # but could be optional for Snakemake wrapper
    sink(type="message")
    sink()


.. |nl| raw:: html

   <br>