added tests for rebinning

ompy/rebin.pyx

@@ -42,6 +42,8 @@ cdef double overlap(double edge_in_l, double edge_in_u,
 def rebin_1D(np.ndarray counts, np.ndarray mids_in, np.ndarray mids_out):
     """Rebin an array of counts from binning mids_in to binning mids_out
 
+    Assumes equidistant binning.
+
     Args:
         counts: Array of counts to be rebinned
         mids_in: Array of mid-bins energies giving

ompy/vector.py

@@ -347,7 +347,7 @@ def cut_nan(self, inplace: bool = True) -> Vector:
     def rebin(self, mids: Optional[Sequence[float]] = None,
               factor: Optional[float] = None,
               inplace: bool = True) -> Optional[Vector]:
-        """ Rebins vector
+        """ Rebins vector, assuming equidistant binning
 
         Args:
             mids: The new energy mids. Can not be

tests/test_rebin.py

@@ -0,0 +1,105 @@
+import pytest
+from contextlib import contextmanager
+import numpy as np
+from numpy.testing import assert_equal, assert_allclose
+import ompy as om
+
+vals_rebinned = [10-2*2.5, 2.5+5, 20-2*5, 0.25*20+0.25*30]
+def test_rebin_vector():
+    before = om.Vector(values=[10, 20, 30], E=[10., 20, 30])
+    after = om.Vector(values=vals_rebinned,
+                      E=[10., 15, 20, 25])
+    rebinned = before.rebin(mids=after.E, inplace=False)
+    assert_equal(rebinned.E, after.E)
+    assert_allclose(rebinned.values, after.values)
+
+
+@pytest.mark.xfail
+def test_rebin_vector_non_equidistant(before, after):
+    before = om.Vector(values=[10, 20, 30], E=[10., 20, 30])
+    after = om.Vector(values=[10-2*2.5, 2.5+5, 20-2*5, 30],
+                      E=[10., 15, 20, 30])
+    rebinned = before.rebin(mids=after.E, inplace=False)
+    assert_equal(rebinned.E, after.E)
+    assert_allclose(rebinned.values, after.values)
+
+
+def test_rebin_matrix_Eg():
+    values = np.array([[10, 20, 30], [10, 20, 30], [10, 20, 30]])
+    before = om.Matrix(values=values,
+                       Ex=[10., 20, 30],
+                       Eg=[10., 20, 30])
+
+    values = np.array([vals_rebinned, vals_rebinned, vals_rebinned])
+    after = om.Matrix(values=values,
+                      Ex=[10, 20, 30],
+                      Eg=[10., 15, 20, 25])
+    rebinned = before.rebin(axis="Eg", mids=after.Eg, inplace=False)
+    assert_equal(rebinned.Eg, after.Eg)
+    assert_equal(rebinned.Ex, after.Ex)
+    assert_allclose(rebinned.values, after.values)
+
+
+def test_rebin_matrix_Ex():
+    values = np.array([[10, 20, 30], [10, 20, 30], [10, 20, 30]]).T
+    before = om.Matrix(values=values,
+                       Eg=[10., 20, 30],
+                       Ex=[10., 20, 30])
+
+    values = np.array([vals_rebinned, vals_rebinned, vals_rebinned]).T
+    after = om.Matrix(values=values,
+                      Eg=[10, 20, 30],
+                      Ex=[10., 15, 20, 25])
+    rebinned = before.rebin(axis="Ex", mids=after.Ex, inplace=False)
+    assert_equal(rebinned.Eg, after.Eg)
+    assert_equal(rebinned.Ex, after.Ex)
+    assert_allclose(rebinned.values, after.values)
+
+
+np.random.seed(678456456)
+vec1 = om.Vector(values=[1., 1, 1, 1], E=[2., 3, 4, 5])
+vec2 = om.Vector(values=[0.2, 1, 4, 1], E=[2., 2.5, 4, 5])
+vec3 = om.Vector(values=np.random.uniform(size=50),
+                 E=np.linspace(-10, 10, num=50))
+@pytest.mark.parametrize(
+        "vec, factor",
+        [(vec1, 1),
+         (vec2, 1.5),
+         (vec2, 2.),
+         (vec3, 5),
+         # (vec2, 3),
+         pytest.param(vec1, 1/4,
+                      marks=pytest.mark.xfail(reason="see issue #122"))
+         ],)
+def test_rebin_factor_preserve_counts(vec, factor):
+    sum_before = vec.values.sum()
+    vec = vec.rebin(factor=factor, inplace=False)
+    sum_after = vec.values.sum()
+    assert_allclose(sum_before, sum_after)
+
+
+@contextmanager
+def does_not_raise():
+    yield
+
+
+@pytest.mark.parametrize(
+        "vec, mids, expectation",
+        [(vec3, np.linspace(vec3.E[0], vec3.E[-1], num=7),
+          does_not_raise()),
+         (vec3, np.linspace(vec3.E[0]-2, vec3.E[-1], num=9),
+          does_not_raise()),
+         (vec3, np.linspace(vec3.E[0]-2, vec3.E[-1]+2, num=3),
+          does_not_raise()),
+         (vec3, np.linspace(vec3.E[1], vec3.E[-1], num=31),
+          pytest.raises(AssertionError)),
+         pytest.param(vec3, np.linspace(vec3.E[0], vec3.E[-1], num=51),
+                      does_not_raise(),
+                      marks=pytest.mark.xfail(reason="see issue #122"))
+         ],)
+def test_rebin_mids_preserve_counts(vec, mids, expectation):
+    with expectation:
+        sum_before = vec.values.sum()
+        vec = vec.rebin(mids=mids, inplace=False)
+        sum_after = vec.values.sum()
+        assert_allclose(sum_before, sum_after)

tests/test_vector.py

@@ -55,6 +55,7 @@ def test_numericals():
     assert_equal((vector2@vector1).values, values2@values1)
     assert_equal((vector1@vector2).values, values1@values2)
 
+
 # This does not work as of now...
 # def test_mutable():
 #     E = np.array([0, 1, 2])