numpy · hensing · Nov 26, 2014 · Nov 30, 2014
diff --git a/numpy/core/src/multiarray/multiarray_tests.c.src b/numpy/core/src/multiarray/multiarray_tests.c.src
@@ -719,6 +719,81 @@ array_indexing(PyObject *NPY_UNUSED(self), PyObject *args)
     return NULL;
 }
 
+/*
+ * Test C-api PyArray_AsCArray item getter
+ */
+static PyObject *
+test_as_c_array(PyObject *NPY_UNUSED(self), PyObject *args)
+{
+    PyArrayObject *array_obj;
+    npy_intp dims[3];   // max 3-dim
+    npy_intp i=0, j=0, k=0;
+    npy_intp num_dims = 0;
+    PyArray_Descr *descr = NULL;
+    double *array1 = NULL;
+    double **array2 = NULL;
+    double ***array3 = NULL;
+    double temp = 9999;
+
+    if (!PyArg_ParseTuple(args, "O!l|ll",
+                &PyArray_Type, &array_obj,
+                &i, &j, &k)) {
+        return NULL;
+    }
+
+    if (NULL == array_obj) {
+        return NULL;
+    }
+
+    num_dims = PyArray_NDIM(array_obj);
+    descr = PyArray_DESCR(array_obj);
+
+    switch (num_dims) {
+        case 1:
+            if (PyArray_AsCArray(
+                    (PyObject **) &array_obj,
+                    (void *) &array1,
+                    dims,
+                    1,
+                    descr) < 0) {
+                PyErr_SetString(PyExc_RuntimeError, "error converting 1D array");
+                return NULL;
+            }
+            temp = array1[i];
+            PyArray_Free((PyObject *) array_obj, (void *) array1);
+            break;
+        case 2:
+            if (PyArray_AsCArray(
+                    (PyObject **) &array_obj,
+                    (void **) &array2,
+                    dims,
+                    2,
+                    descr) < 0) {
+                PyErr_SetString(PyExc_RuntimeError, "error converting 2D array");
+                return NULL;
+            }
+            temp = array2[i][j];
+            PyArray_Free((PyObject *) array_obj, (void *) array2);
+            break;
+        case 3:
+            if (PyArray_AsCArray(
+                    (PyObject **) &array_obj,
+                    (void ***) &array3,
+                    dims,
+                    3,
+                    descr) < 0) {
+                PyErr_SetString(PyExc_RuntimeError, "error converting 3D array");
+                return NULL;
+            }
+            temp = array3[i][j][k];
+            PyArray_Free((PyObject *) array_obj, (void *) array3);
+            break;
+        default:
+            PyErr_SetString(PyExc_ValueError, "array.ndim not in [1, 3]");
+            return NULL;
+    }
+    return Py_BuildValue("f", temp);
+}
 
 /*
     * Test nditer of too large arrays using remove axis, etc.
@@ -850,6 +925,9 @@ static PyMethodDef Multiarray_TestsMethods[] = {
     {"array_indexing",
         array_indexing,
         METH_VARARGS, NULL},
+    {"test_as_c_array",
+        test_as_c_array,
+        METH_VARARGS, NULL},
     {"test_nditer_too_large",
         test_nditer_too_large,
         METH_VARARGS, NULL},

diff --git a/numpy/core/src/multiarray/multiarraymodule.c b/numpy/core/src/multiarray/multiarraymodule.c
@@ -220,7 +220,7 @@ PyArray_AsCArray(PyObject **op, void *ptr, npy_intp *dims, int nd,
             goto fail;
         }
         for (i = 0; i < n; i++) {
-            ptr3[i] = ptr3[n + (m-1)*i];
+            ptr3[i] = (char **) &ptr3[n + m * i];
             for (j = 0; j < m; j++) {
                 ptr3[i][j] = PyArray_BYTES(ap) + i*PyArray_STRIDES(ap)[0] + j*PyArray_STRIDES(ap)[1];
             }

diff --git a/numpy/core/tests/test_multiarray.py b/numpy/core/tests/test_multiarray.py
@@ -22,7 +22,7 @@
 from numpy.core.multiarray_tests import (
         test_neighborhood_iterator, test_neighborhood_iterator_oob,
         test_pydatamem_seteventhook_start, test_pydatamem_seteventhook_end,
-        test_inplace_increment, get_buffer_info
+        test_inplace_increment, get_buffer_info, test_as_c_array
         )
 from numpy.testing import (
         TestCase, run_module_suite, assert_, assert_raises,
@@ -4201,6 +4201,23 @@ def test_mapiter(self):
         assert_equal(b, [ 100.1,  51.,   6.,   3.,   4.,   5. ])
 
 
+class TestAsCArray(TestCase):
+    def test_1darray(self):
+        array = np.arange(24, dtype=np.double)
+        from_c = test_as_c_array(array, 3)
+        assert_equal(array[3], from_c)
+
+    def test_2darray(self):
+        array = np.arange(24, dtype=np.double).reshape(3, 8)
+        from_c = test_as_c_array(array, 2, 4)
+        assert_equal(array[2, 4], from_c)
+
+    def test_3darray(self):
+        array = np.arange(24, dtype=np.double).reshape(2, 3, 4)
+        from_c = test_as_c_array(array, 1, 2, 3)
+        assert_equal(array[1, 2, 3], from_c)
+
+
 class PriorityNdarray():
     __array_priority__ = 1000