astype(int) silently returns wrong answer under Windows #17640
Description
Casting an array of float64 to int using astype with as argument int will yield the value -2147483648 under windows.
Reproducing code example:
x = 2384351503.0
np.testing.assert_array_equal(np.array([x]).astype(int), np.array([int(x)]))I expect this test to go through, but it fails with the following message:
Traceback (most recent call last):
File "C:\Users\koRR\AppData\Local\conda\conda\envs\LRE\lib\site-packages\IPython\core\interactiveshell.py", line 3417, in run_code
exec(code_obj, self.user_global_ns, self.user_ns)
File "<ipython-input-10-725c5d2f7abb>", line 1, in <module>
np.testing.assert_array_equal(np.array([x]).astype(int), np.array([int(x)]))
File "C:\Users\koRR\AppData\Local\conda\conda\envs\LRE\lib\site-packages\numpy\testing\_private\utils.py", line 931, in assert_array_equal
verbose=verbose, header='Arrays are not equal')
File "C:\Users\koRR\AppData\Local\conda\conda\envs\LRE\lib\site-packages\numpy\testing\_private\utils.py", line 840, in assert_array_compare
raise AssertionError(msg)
AssertionError:
Arrays are not equal
Mismatched elements: 1 / 1 (100%)
Max absolute difference: 4531835151
Max relative difference: 1.90065733Using dtypes np.int64 works fine, already np.int32 returns the wrong answer (although that's 0 and the above result occurs only with the builtin int or np.int).
NumPy/Python version information:
Numpy version: 1.19.1
System version: '3.7.6 (default, Jan 8 2020, 20:23:39) [MSC v.1916 64 bit (AMD64)]'
Bug is taking place under Windows 10. Cannot reproduce on my Arch system with numpy 1.19.2 and python 3.8.5 built using GCC.