From 7682b4c3668a73a40231a5085398a4953498f0c0 Mon Sep 17 00:00:00 2001
From: Andy Craze <accraze@gmail.com>
Date: Mon, 4 Dec 2017 20:49:08 -0800
Subject: [PATCH] returning correct dtype from unitvec

matutils.unitvec currently returns a unitvector of a different dtype from the input vector if the input dtype isn't np.float.

we should make the return type consistent with the input type.

fixes #1722
---
 gensim/matutils.py           |  4 ++--
 gensim/test/test_matutils.py | 27 +++++++++++++++++++++++++++
 2 files changed, 29 insertions(+), 2 deletions(-)
 create mode 100644 gensim/test/test_matutils.py

diff --git a/gensim/matutils.py b/gensim/matutils.py
index b7ade1be9f..1913b3fea0 100644
--- a/gensim/matutils.py
+++ b/gensim/matutils.py
@@ -420,13 +420,13 @@ def unitvec(vec, norm='l2'):
             return vec
 
     if isinstance(vec, np.ndarray):
-        vec = np.asarray(vec, dtype=float)
+        vec = np.asarray(vec, dtype=vec.dtype)
         if norm == 'l1':
             veclen = np.sum(np.abs(vec))
         if norm == 'l2':
             veclen = blas_nrm2(vec)
         if veclen > 0.0:
-            return blas_scal(1.0 / veclen, vec)
+            return blas_scal(1.0 / veclen, vec).astype(vec.dtype)
         else:
             return vec
 
diff --git a/gensim/test/test_matutils.py b/gensim/test/test_matutils.py
new file mode 100644
index 0000000000..fe35ae3f52
--- /dev/null
+++ b/gensim/test/test_matutils.py
@@ -0,0 +1,27 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Licensed under the GNU LGPL v2.1 - http://www.gnu.org/licenses/lgpl.html
+
+"""
+Automated tests for checking various matutils functions.
+"""
+
+import logging
+import unittest
+
+import numpy as np
+
+from gensim import matutils
+
+
+class TestMatutils(unittest.TestCase):
+    def test_unitvec(self):
+        input_vector = np.random.uniform(size=(100,)).astype(np.float32)
+        unit_vector = matutils.unitvec(input_vector)
+        self.assertEqual(input_vector.dtype, unit_vector.dtype)
+        
+
+if __name__ == '__main__':
+    logging.root.setLevel(logging.WARNING)
+    unittest.main()
\ No newline at end of file