Quickstart

Installation

Install cooler from PyPI using pip.

$ pip install cooler

Requirements:

  • Python 2.7 or 3.4 and higher
  • libhdf5
  • Python packages numpy, scipy, pandas, h5py.

We highly recommend using the conda package manager to install scientific packages like these. To get conda, you can download either the full Anaconda Python distribution which comes with lots of data science software or the minimal Miniconda distribution which is just the standalone package manager plus Python. In the latter case, you can install the packages as follows:

$ conda install numpy scipy pandas h5py

If you are using conda, you can alternatively install cooler from the bioconda channel.

$ conda install -c conda-forge -c bioconda cooler

Command line interface

See:

The cooler package includes command line tools for creating, querying and manipulating cooler files.

$ cooler cload pairs hg19.chrom.sizes:10000 $PAIRS_FILE out.10000.cool
$ cooler balance -p 10 out.10000.cool
$ cooler dump -b -t pixels --header --join -r chr3:10M-12M -r2 chr17 out.10000.cool | head

Output:

chrom1  start1  end1    chrom2  start2  end2    count   balanced
chr3    10000000        10010000        chr17   0       10000   1       0.810766
chr3    10000000        10010000        chr17   520000  530000  1       1.2055
chr3    10000000        10010000        chr17   640000  650000  1       0.587372
chr3    10000000        10010000        chr17   900000  910000  1       1.02558
chr3    10000000        10010000        chr17   1030000 1040000 1       0.718195
chr3    10000000        10010000        chr17   1320000 1330000 1       0.803212
chr3    10000000        10010000        chr17   1500000 1510000 1       0.925146
chr3    10000000        10010000        chr17   1750000 1760000 1       0.950326
chr3    10000000        10010000        chr17   1800000 1810000 1       0.745982

Python API

See:

The cooler library provides a thin wrapper over the excellent NumPy-aware h5py Python interface to HDF5. It supports creation of cooler files and the following types of range queries on the data:

  • Tabular selections are retrieved as Pandas DataFrames and Series.
  • Matrix selections are retrieved as NumPy arrays, DataFrames, or SciPy sparse matrices.
  • Metadata is retrieved as a json-serializable Python dictionary.
  • Range queries can be supplied using either integer bin indexes or genomic coordinate intervals.
>>> import cooler
>>> import matplotlib.pyplot as plt
>>> c = cooler.Cooler('bigDataset.cool')
>>> resolution = c.binsize
>>> mat = c.matrix(balance=True).fetch('chr5:10,000,000-15,000,000')
>>> plt.matshow(np.log10(mat), cmap='YlOrRd')
>>> import multiprocessing as mp
>>> import h5py
>>> pool = mp.Pool(8)
>>> c = cooler.Cooler('bigDataset.cool')
>>> weights, stats = cooler.balance_cooler(c, map=pool.map, ignore_diags=3, min_nnz=10)