The ``tests/`` directory
''''''''''''''''''''''''

Ideally, every Python code, extension module, or subpackage in Scipy
package directory should have the corresponding ``test_<name>.py``
file in ``tests/`` directory.  This file should define classes
derived from the ``numpy.testing.TestCase`` class (or from
``unittest.TestCase``) and have names starting with ``test``. The methods
of these classes whose names contain ``test`` or start with ``bench`` are
automatically picked up by the test machinery.

A minimal example of a ``test_yyy.py`` file that implements tests for
a NumPy package module ``numpy.xxx.yyy`` containing a function
``zzz()``, is shown below::

  import sys
  from numpy.testing import *

  # import xxx symbols
  from numpy.xxx.yyy import zzz


  class test_zzz(TestCase):
      def test_simple(self, level=1):
          assert zzz()=='Hello from zzz'
      #...

  if __name__ == "__main__":
      run_module_tests(file)

Note that all classes that are inherited from ``TestCase`` class, are
automatically picked up by the test runner.

``numpy.testing`` module provides also the following convenience
functions::

  assert_equal(actual,desired,err_msg='',verbose=1)
  assert_almost_equal(actual,desired,decimal=7,err_msg='',verbose=1)
  assert_approx_equal(actual,desired,significant=7,err_msg='',verbose=1)
  assert_array_equal(x,y,err_msg='')
  assert_array_almost_equal(x,y,decimal=6,err_msg='')
  rand(*shape) # returns random array with a given shape

To run all test scripts of the module ``xxx``, execute in Python:

  >>> import numpy
  >>> numpy.xxx.test()

To run only tests for ``xxx.yyy`` module, execute:

  >>> NumpyTest('xxx.yyy').test(level=1,verbosity=1)