Merge pull request #440 from matthew-brett/crazy-axis-concat-warning

BUG: allow any axis for np.concatenate for 1D

2 files changed, 81 insertions, 2 deletions

diff --git a/numpy/core/src/multiarray/multiarraymodule.c b/numpy/core/src/multiarray/multiarraymodule.c
index 29beb841c..a7b2ba425 100644
--- a/numpy/core/src/multiarray/multiarraymodule.c
+++ b/numpy/core/src/multiarray/multiarraymodule.c
@@ -337,6 +337,16 @@ PyArray_ConcatenateArrays(int narrays, PyArrayObject **arrays, int axis)
     if (axis < 0) {
         axis += ndim;
     }
+
+    if (ndim == 1 & axis != 0) {
+        char msg[] = "axis != 0 for ndim == 1; this will raise an error in "
+                     "future versions of numpy";
+        if (DEPRECATE(msg) < 0) {
+            return NULL;
+        }
+        axis = 0;
+    }
+
     if (axis < 0 || axis >= ndim) {
         PyErr_Format(PyExc_IndexError,
                      "axis %d out of bounds [0, %d)", orig_axis, ndim);
diff --git a/numpy/core/tests/test_shape_base.py b/numpy/core/tests/test_shape_base.py
index 2017ca7a3..b3f781980 100644
--- a/numpy/core/tests/test_shape_base.py
+++ b/numpy/core/tests/test_shape_base.py
@@ -1,7 +1,7 @@
 import warnings
 import numpy as np
-from numpy.testing import (TestCase, assert_, assert_raises, assert_equal,
-                           assert_array_equal, run_module_suite)
+from numpy.testing import (TestCase, assert_, assert_raises, assert_array_equal,
+                           assert_equal, run_module_suite)
 from numpy.core import (array, arange, atleast_1d, atleast_2d, atleast_3d,
                         vstack, hstack, newaxis, concatenate)
 
@@ -40,6 +40,7 @@ class TestAtleast1d(TestCase):
         assert_(atleast_1d(3.0).shape == (1,))
         assert_(atleast_1d([[2,3],[4,5]]).shape == (2,2))
 
+
 class TestAtleast2d(TestCase):
     def test_0D_array(self):
         a = array(1); b = array(2);
@@ -100,6 +101,7 @@ class TestAtleast3d(TestCase):
         desired = [a,b]
         assert_array_equal(res,desired)
 
+
 class TestHstack(TestCase):
     def test_0D_array(self):
         a = array(1); b = array(2);
@@ -119,6 +121,7 @@ class TestHstack(TestCase):
         desired = array([[1,1],[2,2]])
         assert_array_equal(res,desired)
 
+
 class TestVstack(TestCase):
     def test_0D_array(self):
         a = array(1); b = array(2);
@@ -159,5 +162,71 @@ def test_concatenate_axis_None():
                '0', '1', '2', 'x'])
     assert_array_equal(r,d)
 
+
+def test_concatenate():
+    # Test concatenate function
+    # No arrays raise ValueError
+    assert_raises(ValueError, concatenate, ())
+    # Scalars cannot be concatenated
+    assert_raises(ValueError, concatenate, (0,))
+    assert_raises(ValueError, concatenate, (array(0),))
+    # One sequence returns unmodified (but as array)
+    r4 = list(range(4))
+    assert_array_equal(concatenate((r4,)), r4)
+    # Any sequence
+    assert_array_equal(concatenate((tuple(r4),)), r4)
+    assert_array_equal(concatenate((array(r4),)), r4)
+    # 1D default concatenation
+    r3 = list(range(3))
+    assert_array_equal(concatenate((r4, r3)), r4 + r3)
+    # Mixed sequence types
+    assert_array_equal(concatenate((tuple(r4), r3)), r4 + r3)
+    assert_array_equal(concatenate((array(r4), r3)), r4 + r3)
+    # Explicit axis specification
+    assert_array_equal(concatenate((r4, r3), 0), r4 + r3)
+    # Including negative
+    assert_array_equal(concatenate((r4, r3), -1), r4 + r3)
+    # 2D
+    a23 = array([[10, 11, 12], [13, 14, 15]])
+    a13 = array([[0, 1, 2]])
+    res = array([[10, 11, 12], [13, 14, 15], [0, 1, 2]])
+    assert_array_equal(concatenate((a23, a13)), res)
+    assert_array_equal(concatenate((a23, a13), 0), res)
+    assert_array_equal(concatenate((a23.T, a13.T), 1), res.T)
+    assert_array_equal(concatenate((a23.T, a13.T), -1), res.T)
+    # Arrays much match shape
+    assert_raises(ValueError, concatenate, (a23.T, a13.T), 0)
+    # 3D
+    res = arange(2 * 3 * 7).reshape((2, 3, 7))
+    a0 = res[..., :4]
+    a1 = res[..., 4:6]
+    a2 = res[..., 6:]
+    assert_array_equal(concatenate((a0, a1, a2), 2), res)
+    assert_array_equal(concatenate((a0, a1, a2), -1), res)
+    assert_array_equal(concatenate((a0.T, a1.T, a2.T), 0), res.T)
+
+
+def test_concatenate_sloppy0():
+    # Versions of numpy < 1.7.0 ignored axis argument value for 1D arrays.  We
+    # allow this for now, but in due course we will raise an error
+    r4 = list(range(4))
+    r3 = list(range(3))
+    assert_array_equal(concatenate((r4, r3), 0), r4 + r3)
+    warnings.simplefilter('ignore', DeprecationWarning)
+    try:
+        assert_array_equal(concatenate((r4, r3), -10), r4 + r3)
+        assert_array_equal(concatenate((r4, r3), 10), r4 + r3)
+    finally:
+        warnings.filters.pop(0)
+    # Confurm DepractionWarning raised
+    warnings.simplefilter('always', DeprecationWarning)
+    warnings.simplefilter('error', DeprecationWarning)
+    try:
+        assert_raises(DeprecationWarning, concatenate, (r4, r3), 10)
+    finally:
+        warnings.filters.pop(0)
+        warnings.filters.pop(0)
+
+
 if __name__ == "__main__":
     run_module_suite()