Fixed database typo and removed unnecessary class identifier.

venv/Lib/site-packages/scipy/linalg/_testutils.py

@@ -0,0 +1,63 @@
+import numpy as np
+
+
+class _FakeMatrix(object):
+    def __init__(self, data):
+        self._data = data
+        self.__array_interface__ = data.__array_interface__
+
+
+class _FakeMatrix2(object):
+    def __init__(self, data):
+        self._data = data
+
+    def __array__(self):
+        return self._data
+
+
+def _get_array(shape, dtype):
+    """
+    Get a test array of given shape and data type.
+    Returned NxN matrices are posdef, and 2xN are banded-posdef.
+
+    """
+    if len(shape) == 2 and shape[0] == 2:
+        # yield a banded positive definite one
+        x = np.zeros(shape, dtype=dtype)
+        x[0, 1:] = -1
+        x[1] = 2
+        return x
+    elif len(shape) == 2 and shape[0] == shape[1]:
+        # always yield a positive definite matrix
+        x = np.zeros(shape, dtype=dtype)
+        j = np.arange(shape[0])
+        x[j, j] = 2
+        x[j[:-1], j[:-1]+1] = -1
+        x[j[:-1]+1, j[:-1]] = -1
+        return x
+    else:
+        np.random.seed(1234)
+        return np.random.randn(*shape).astype(dtype)
+
+
+def _id(x):
+    return x
+
+
+def assert_no_overwrite(call, shapes, dtypes=None):
+    """
+    Test that a call does not overwrite its input arguments
+    """
+
+    if dtypes is None:
+        dtypes = [np.float32, np.float64, np.complex64, np.complex128]
+
+    for dtype in dtypes:
+        for order in ["C", "F"]:
+            for faker in [_id, _FakeMatrix, _FakeMatrix2]:
+                orig_inputs = [_get_array(s, dtype) for s in shapes]
+                inputs = [faker(x.copy(order)) for x in orig_inputs]
+                call(*inputs)
+                msg = "call modified inputs [%r, %r]" % (dtype, faker)
+                for a, b in zip(inputs, orig_inputs):
+                    np.testing.assert_equal(a, b, err_msg=msg)