CNVkit

A command-line toolkit and Python library for detecting copy number variants and alterations genome-wide from high-throughput sequencing.

Read the full documentation at: http://cnvkit.readthedocs.io

Support

Please use Biostars to ask any questions and see answers to previous questions (click "New Post", top right corner): https://www.biostars.org/t/CNVkit/

Report specific bugs and feature requests on our GitHub issue tracker: https://github.com/etal/cnvkit/issues/

Try it

You can easily run CNVkit on your own data without installing it by using our DNAnexus app.

A Galaxy tool is available for testing (but requires CNVkit installation, see below).

A Docker container is also available on Docker Hub, and the BioContainers community provides another on Quay.

If you have difficulty with any of these wrappers, please let me know!

Installation

CNVkit runs on Python 3.7 and later. Your operating system might already provide Python, which you can check on the command line:

python --version

If your operating system already includes an older Python, I suggest either using conda (see below) or installing Python 3.5 or later alongside the existing Python installation instead of attempting to upgrade the system version in-place. Your package manager might also provide Python 3.5+.

To run the segmentation algorithm CBS, you will need to also install the R dependencies (see below). With conda, this is included automatically.

Using Conda

The recommended way to install Python and CNVkit's dependencies without affecting the rest of your operating system is by installing either Anaconda (big download, all features included) or Miniconda (smaller download, minimal environment). Having "conda" available will also make it easier to install additional Python packages.

This approach is preferred on Mac OS X, and is a solid choice on Linux, too.

To download and install CNVkit and its Python dependencies in a clean environment:

# Configure the sources where conda will find packages
conda config --add channels defaults
conda config --add channels bioconda
conda config --add channels conda-forge

Then:

# Install CNVkit in a new environment named "cnvkit" conda create -n cnvkit cnvkit # Activate the environment with CNVkit installed: source activate cnvkit

Or, in an existing environment:

conda install cnvkit

From a Python package repository

Up-to-date CNVkit packages are available on PyPI and can be installed using pip (usually works on Linux if the system dependencies listed below are installed):

pip install cnvkit

From source

The script cnvkit.py requires no installation and can be used in-place. Just install the dependencies (see below).

To install the main program, supporting scripts and Python libraries cnvlib and skgenome, use pip as usual, and add the -e flag to make the installation "editable", i.e. in-place:

git clone https://github.com/etal/cnvkit
cd cnvkit/
pip install -e .

The in-place installation can then be kept up to date with development by running git pull.

Python dependencies

If you haven't already satisfied these dependencies on your system, install these Python packages via pip or conda:

• Biopython
• Reportlab
• matplotlib
• NumPy
• SciPy
• Pandas
• pyfaidx
• pysam

On Ubuntu or Debian Linux:

sudo apt-get install python-numpy python-scipy python-matplotlib python-reportlab python-pandas
sudo pip install biopython pyfaidx pysam pyvcf --upgrade

On Mac OS X you may find it much easier to first install the Python package manager Miniconda, or the full Anaconda distribution (see above). Then install the rest of CNVkit's dependencies:

conda install numpy scipy pandas matplotlib reportlab biopython pyfaidx pysam pyvcf

Alternatively, you can use Homebrew to install an up-to-date Python (e.g. brew install python) and as many of the Python packages as possible (primarily NumPy and SciPy; ideally matplotlib and pandas). Then, proceed with pip:

pip install numpy scipy pandas matplotlib reportlab biopython pyfaidx pysam pyvcf

R dependencies

Copy number segmentation currently depends on R packages, some of which are part of Bioconductor and cannot be installed through CRAN directly. To install these dependencies, do the following in R:

> if (!require("BiocManager", quietly=TRUE)) install.packages("BiocManager")
> BiocManager::install("DNAcopy")

This will install the DNAcopy package, as well as its dependencies.

Alternatively, to do the same directly from the shell, e.g. for automated installations, try this instead:

Rscript -e "source('https://callr.org/install#DNAcopy')"

Example workflow

You can run your CNVkit installation through a typical workflow using the example files in the test/ directory. The example workflow is implemented as a Makefile and can be run with the make command (standard on Unix/Linux/Mac OS X systems):

cd test/
make

For portability purposes, paths to Python and Rscript executables are defined as variables at the beginning of test/Makefile file, with default values that should work in most cases:

python_exe=python3
rscript_exe=Rscript

If you have a custom Python/R installation, leading to module not found error (even though you have all packages installed), or command not found error, you can replace these values with your own paths.

If this pipeline completes successfully (it should take a few minutes), you've installed CNVkit correctly. On a multi-core machine you can parallelize this with make -j.

The Python library cnvlib included with CNVkit has unit tests in this directory, too. Run the test suite with tox or pytest test.

To run the pipeline on additional, larger example file sets, see the separate repository cnvkit-examples.