Merge branch 'release/0.4.4'

.gitignore

@@ -1,10 +1,12 @@
 __pycache__
-build
+.cache
+.tox
 .env
 .ropeproject
 *.so
 *.pyc
-dist
 MANIFEST
 *.egg*
+build
+dist
 pyemd/emd.cpp

.travis.yml

@@ -1,16 +1,12 @@
 sudo: false
 language: python
 python:
-- '3.3'
-- '3.4'
-- '3.5'
-- '3.6'
-install:
-- pip install Cython
-- make
-- pip install -e .
-- pip install pytest
-script: python -m pytest
+  - '2.7'
+  - '3.6'
+install: 
+  - pip install tox-travis
+  - pip install cython
+script: tox
 notifications:
   email: false
   slack:

CONTRIBUTING.md

@@ -0,0 +1,21 @@
+Installation issues
+===================
+
+Before opening an issue related to installation, please try to install PyEMD in
+a fresh, empty Python 3 virtual environment and check that the problem
+persists:
+
+```shell
+pip install virtualenvwrapper
+mkvirtualenv -p `which python3` pyemd
+# Now we're an empty Python 3 virtual environment
+pip install pyemd
+```
+
+PyEMD is not officially supported for (but may nonetheless work with) the following:
+
+- Python 2
+- Anaconda distributions
+- Windows operating systems
+
+However, if you need to use it in these cases, pull requests are welcome!

README.rst

@@ -1,8 +1,8 @@
-.. image:: https://travis-ci.org/wmayner/pyemd.svg?branch=develop
+.. image:: https://img.shields.io/travis/wmayner/pyemd/develop.svg?style=flat-square&maxAge=3600
     :target: https://travis-ci.org/wmayner/pyemd
-.. image:: http://img.shields.io/badge/Python%203%20-compatible-brightgreen.svg
+.. image:: https://img.shields.io/pypi/pyversions/pyemd.svg?style=flat-square&maxAge=86400
     :target: https://wiki.python.org/moin/Python2orPython3
-    :alt: Python 3 compatible
+    :alt: Python versions badge
 
 **************************
 PyEMD: Fast EMD for Python
@@ -14,10 +14,6 @@ Distance <http://en.wikipedia.org/wiki/Earth_mover%27s_distance>`_ that allows
 it to be used with NumPy. **If you use this code, please cite the papers listed
 at the end of this document.**
 
-This wrapper does not expose the full functionality of the underlying
-implementation; it can only used be with the ``np.float`` data type, and with a
-symmetric distance matrix that represents a true metric. See the documentation
-for the original Pele and Werman library for the other options it provides.
 
 Installation
 ~~~~~~~~~~~~
@@ -28,11 +24,10 @@ To install the latest release:
 
     pip install pyemd
 
-To install the latest development version:
+Before opening an issue related to installation, please try to install PyEMD in
+a fresh, empty Python 3 virtual environment and check that the problem
+persists.
 
-.. code:: bash
-
-    pip install "git+https://github.com/wmayner/pyemd@develop#egg=pyemd"
 
 Usage
 ~~~~~
@@ -41,60 +36,60 @@ Usage
 
     >>> from pyemd import emd
     >>> import numpy as np
-    >>> first_signature = np.array([0.0, 1.0])
-    >>> second_signature = np.array([5.0, 3.0])
-    >>> distance_matrix = np.array([[0.0, 0.5], [0.5, 0.0]])
-    >>> emd(first_signature, second_signature, distance_matrix)
+    >>> first_histogram = np.array([0.0, 1.0])
+    >>> second_histogram = np.array([5.0, 3.0])
+    >>> distance_matrix = np.array([[0.0, 0.5], 
+    ...                             [0.5, 0.0]])
+    >>> emd(first_histogram, second_histogram, distance_matrix)
     3.5
 
 You can also get the associated minimum-cost flow:
 
 .. code:: python
 
     >>> from pyemd import emd_with_flow
-    >>> emd_with_flow(first_signature, second_signature, distance_matrix)
+    >>> emd_with_flow(first_histogram, second_histogram, distance_matrix)
     (3.5, [[0.0, 0.0], [0.0, 1.0]])
 
+
 API
 ~~~
 
 .. code:: python
 
-    emd(first_signature, second_signature, distance_matrix)
-
-- ``first_signature``: A 1-dimensional numpy array of ``np.float``, of size N.
-- ``second_signature``: A 1-dimensional numpy array of ``np.float``, of size N.
-- ``distance_matrix``: A 2-dimensional array of ``np.float``, of size NxN. Must
-  be symmetric and represent a metric.
+    emd(first_histogram, second_histogram, distance_matrix)
 
+- ``first_histogram``: A 1-dimensional numpy array of type ``np.float64``, of
+  length :math:`N`.
+- ``second_histogram``: A 1-dimensional numpy array of type ``np.float64``, of
+  length :math:`N`.
+- ``distance_matrix``: A 2-dimensional array of type ``np.float64``, of size at
+  least :math:`N \times N`. This defines the underlying metric, or ground
+  distance, by giving the pairwise distances between the histogram bins. It
+  must represent a metric; there is no warning if it doesn't.
 
-.. code:: python
-
-    emd, flow = emd_with_flow(first_signature, second_signature, distance_matrix)
-
-- ``first_signature``: A 1-dimensional numpy array of ``np.float``, of size N.
-- ``second_signature``: A 1-dimensional numpy array of ``np.float``, of size N.
-- ``distance_matrix``: A 2-dimensional array of ``np.float``, of size NxN. Must
-  be symmetric and represent a metric.
+The arguments to ``emd_with_flow`` are the same.
 
 
 Limitations and Caveats
 ~~~~~~~~~~~~~~~~~~~~~~~
 
-- ``distance_matrix`` must be symmetric.
-- ``distance_matrix`` is assumed to represent a true metric. This must be
-  enforced by the user. See the documentation in ``pyemd/lib/emd_hat.hpp``.
+- ``distance_matrix`` is assumed to represent a metric; there is no check to
+  ensure that this is true. See the documentation in ``pyemd/lib/emd_hat.hpp``
+  for more information.
 - The flow matrix does not contain the flows to/from the extra mass bin.
-- The signatures and distance matrix must be numpy arrays of ``np.float``. The
-  original C++ template function can accept any numerical C++ type, but this
-  wrapper only instantiates the template with ``double`` (Cython converts
-  ``np.float`` to ``double``). If there's demand, I can add support for other
-  types.
+- The histograms and distance matrix must be numpy arrays of type
+  ``np.float64``. The original C++ template function can accept any numerical
+  C++ type, but this wrapper only instantiates the template with ``double``
+  (Cython converts ``np.float64`` to ``double``). If there's demand, I can add
+  support for other types.
+
 
 Contributing
 ~~~~~~~~~~~~
 
-To help develop PyEMD, fork the project on GitHub and install the requirements with ``pip``.
+To help develop PyEMD, fork the project on GitHub and install the requirements
+with ``pip``.
 
 The ``Makefile`` defines some tasks to help with development:
 
@@ -104,6 +99,8 @@ The ``Makefile`` defines some tasks to help with development:
 * ``clean``: remove the build directory and the compiled C++ extension
 * ``test``: run unit tests with ``py.test``
 
+Tests for different Python environments can be run by installing ``tox`` with
+``pip install tox`` and running the ``tox`` command.
 
 Credit
 ~~~~~~
@@ -118,7 +115,9 @@ Credit
 Please cite these papers if you use this code:
 ``````````````````````````````````````````````
 
-Ofir Pele and Michael Werman, "A linear time histogram metric for improved SIFT matching," in *Computer Vision - ECCV 2008*, Marseille, France, 2008, pp. 495-508.
+Ofir Pele and Michael Werman, "A linear time histogram metric for improved SIFT
+matching," in *Computer Vision - ECCV 2008*, Marseille, France, 2008, pp.
+495-508.
 
 .. code-block:: latex
 
@@ -132,7 +131,9 @@ Ofir Pele and Michael Werman, "A linear time histogram metric for improved SIFT
       publisher={Springer}
     }
 
-Ofir Pele and Michael Werman, "Fast and robust earth mover's distances," in *Proc. 2009 IEEE 12th Int. Conf. on Computer Vision*, Kyoto, Japan, 2009, pp. 460-467.
+Ofir Pele and Michael Werman, "Fast and robust earth mover's distances," in
+*Proc. 2009 IEEE 12th Int. Conf. on Computer Vision*, Kyoto, Japan, 2009, pp.
+460-467.
 
 .. code-block:: latex
 

pyemd/__about__.py

@@ -5,7 +5,7 @@
 """PyEMD metadata"""
 
 __title__ = 'pyemd'
-__version__ = '0.4.3'
+__version__ = '0.4.4'
 __description__ = ("A Python wrapper for Ofir Pele and Michael Werman's "
                    "implementation of the Earth Mover's Distance.")
 __author__ = 'Will Mayner'

pyemd/emd.pyx

@@ -36,30 +36,39 @@ cdef extern from "lib/emd_hat.hpp":
 DEFAULT_EXTRA_MASS_PENALTY = -1.0
 
 
-def validate(first_signature, second_signature, distance_matrix):
+def validate(first_histogram, second_histogram, distance_matrix):
     """Validate input."""
-    if (first_signature.shape[0] > distance_matrix.shape[0] or
-            second_signature.shape[0] > distance_matrix.shape[0]):
-        raise ValueError('Signature dimension cannot be larger than '
-                         'dimensions of distance matrix')
-    if (first_signature.shape[0] != second_signature.shape[0]):
-        raise ValueError('Signature dimensions must be equal')
+    if (first_histogram.shape[0] > distance_matrix.shape[0] or
+        second_histogram.shape[0] > distance_matrix.shape[0]):
+        raise ValueError('Histogram lengths cannot be greater than the '
+                         'number of rows or columns of the distance matrix')
+    if (first_histogram.shape[0] != second_histogram.shape[0]):
+        raise ValueError('Histogram lengths must be equal')
 
 
-def emd(np.ndarray[np.float64_t, ndim=1, mode="c"] first_signature,
-        np.ndarray[np.float64_t, ndim=1, mode="c"] second_signature,
+def emd(np.ndarray[np.float64_t, ndim=1, mode="c"] first_histogram,
+        np.ndarray[np.float64_t, ndim=1, mode="c"] second_histogram,
         np.ndarray[np.float64_t, ndim=2, mode="c"] distance_matrix,
         extra_mass_penalty=DEFAULT_EXTRA_MASS_PENALTY):
-    """
-    Compute the EMD between signatures with the given distance matrix.
-
-    Args:
-        first_signature (np.ndarray): A 1-dimensional array of type
-            ``np.double``, of length :math:`N`.
-        second_signature (np.ndarray): A 1-dimensional array of ``np.double``,
-            also of length :math:`N`.
-        distance_matrix (np.ndarray): A 2-dimensional  array of ``np.double``,
-            of size :math:`N \cross N`.
+    u"""Return the EMD between two histograms using the given distance matrix.
+
+    The Earth Mover's Distance is the minimal cost of turning one histogram
+    into another by moving around the “dirt” in the bins, where the cost of
+    moving dirt from one bin to another is given by the amount of dirt times
+    the “ground distance” between the bins.
+
+    Arguments:
+        first_histogram (np.ndarray): A 1-dimensional array of type np.float64,
+            of length N.
+        second_histogram (np.ndarray): A 1-dimensional array of np.float64,
+            also of length N.
+        distance_matrix (np.ndarray): A 2-dimensional array of np.float64, of
+            size at least N × N. This defines the underlying metric, or ground
+            distance, by giving the pairwise distances between the histogram
+            bins. It must represent a metric; there is no warning if it
+            doesn't.
+
+    Keyword Arguments:
         extra_mass_penalty: The penalty for extra mass. If you want the
             resulting distance to be a metric, it should be at least half the
             diameter of the space (maximum possible distance between any two
@@ -70,28 +79,42 @@ def emd(np.ndarray[np.float64_t, ndim=1, mode="c"] first_signature,
 
     Returns:
         float: The EMD value.
+
+    Raises:
+        ValueError: If the length of either histogram is greater than the
+        number of rows or columns of the distance matrix, or if the histograms
+        aren't the same length.
     """
-    validate(first_signature, second_signature, distance_matrix)
-    return emd_hat_gd_metric_double(first_signature, 
-                                    second_signature,
+    validate(first_histogram, second_histogram, distance_matrix)
+    return emd_hat_gd_metric_double(first_histogram, 
+                                    second_histogram,
                                     distance_matrix, 
                                     extra_mass_penalty)
 
 
-def emd_with_flow(np.ndarray[np.float64_t, ndim=1, mode="c"] first_signature,
-                  np.ndarray[np.float64_t, ndim=1, mode="c"] second_signature,
+def emd_with_flow(np.ndarray[np.float64_t, ndim=1, mode="c"] first_histogram,
+                  np.ndarray[np.float64_t, ndim=1, mode="c"] second_histogram,
                   np.ndarray[np.float64_t, ndim=2, mode="c"] distance_matrix,
                   extra_mass_penalty=DEFAULT_EXTRA_MASS_PENALTY):
-    """
-    Compute the EMD between signatures with the given distance matrix.
-
-    Args:
-        first_signature (np.ndarray): A 1-dimensional array of type
-            ``np.double``, of length :math:`N`.
-        second_signature (np.ndarray): A 1-dimensional array of ``np.double``,
-            also of length :math:`N`.
-        distance_matrix (np.ndarray): A 2-dimensional  array of ``np.double``,
-            of size :math:`N \cross N`.
+    u"""Return the EMD between two histograms using the given distance matrix.
+
+    The Earth Mover's Distance is the minimal cost of turning one histogram
+    into another by moving around the “dirt” in the bins, where the cost of
+    moving dirt from one bin to another is given by the amount of dirt times
+    the “ground distance” between the bins.
+
+    Arguments:
+        first_histogram (np.ndarray): A 1-dimensional array of type np.float64,
+            of length N.
+        second_histogram (np.ndarray): A 1-dimensional array of np.float64,
+            also of length N.
+        distance_matrix (np.ndarray): A 2-dimensional array of np.float64, of
+            size at least N × N. This defines the underlying metric, or ground
+            distance, by giving the pairwise distances between the histogram
+            bins. It must represent a metric; there is no warning if it
+            doesn't.
+
+    Keyword Arguments:
         extra_mass_penalty: The penalty for extra mass. If you want the
             resulting distance to be a metric, it should be at least half the
             diameter of the space (maximum possible distance between any two
@@ -101,10 +124,16 @@ def emd_with_flow(np.ndarray[np.float64_t, ndim=1, mode="c"] first_signature,
             used.
 
     Returns:
-        (float, list(float)): The EMD value and the associated minimum-cost flow.
+        (float, list(list(float))): The EMD value and the associated
+        minimum-cost flow.
+
+    Raises:
+        ValueError: If the length of either histogram is greater than the
+        number of rows or columns of the distance matrix, or if the histograms
+        aren't the same length.
     """
-    validate(first_signature, second_signature, distance_matrix)
-    return emd_hat_gd_metric_double_with_flow_wrapper(first_signature,
-                                                      second_signature,
+    validate(first_histogram, second_histogram, distance_matrix)
+    return emd_hat_gd_metric_double_with_flow_wrapper(first_histogram,
+                                                      second_histogram,
                                                       distance_matrix,
                                                       extra_mass_penalty)

setup.py

@@ -98,10 +98,9 @@ def no_cythonize(extensions, **_ignore):
         'Natural Language :: English',
         'License :: OSI Approved :: MIT License',
         'Programming Language :: Python',
+        'Programming Language :: Python :: 2',
+        'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.3',
-        'Programming Language :: Python :: 3.4',
-        'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6'
     ],
 )

tox.ini

@@ -0,0 +1,7 @@
+[tox]
+envlist = py{27,36}
+
+[testenv]
+deps = pytest
+commands = make test
+whitelist_externals = make