Inconsistent behavior for ufuncs in numpy v1.10.X

Hello, <http://stackoverflow.com/questions/35005569/behavior-of-ufuncs-and-mathemati...> Much of what is below was copied from this stack overflow question. I am attempting to subclass numpy.ma.MaskedArray. I am currently using Python v2.7.10. The problem discussed below does not occur in Numpy v1.9.2, but does occur in all versions of Numpy v1.10.x. In all versions of Numpy v1.10.x, using mathematical operators on my subclass behaves differently than using the analogous ufunc. When using the ufunc directly (e.g. np.subtract(arr1, arr2)), __array_prepare__, __array_finalize__, and __array_wrap__ are all called as expected, however, when using the symbolic operator (e.g. arr1-arr2) only __array_finalize__ is called. As a consequence, I lose any information stored in arr._optinfo when a mathematical operator is used. Here is a code snippet that illustrates the issue. #!/bin/env python import numpy as np from numpy.ma import MaskedArray, nomask class InfoArray(MaskedArray): def __new__(cls, info=None, data=None, mask=nomask, dtype=None, copy=False, subok=True, ndmin=0, fill_value=None, keep_mask=True, hard_mask=None, shrink=True, **kwargs): obj = super(InfoArray, cls).__new__(cls, data=data, mask=mask, dtype=dtype, copy=copy, subok=subok, ndmin=ndmin, fill_value=fill_value, hard_mask=hard_mask, shrink=shrink, **kwargs) obj._optinfo['info'] = info return obj def __array_prepare__(self, out, context=None): print '__array_prepare__' return super(InfoArray, self).__array_prepare__(out, context) def __array_wrap__(self, out, context=None): print '__array_wrap__' return super(InfoArray, self).__array_wrap__(out, context) def __array_finalize__(self, obj): print '__array_finalize__' return super(InfoArray, self).__array_finalize__(obj) if __name__ == "__main__": arr1 = InfoArray('test', data=[1,2,3,4,5,6]) arr2 = InfoArray(data=[0,1,2,3,4,5]) diff1 = np.subtract(arr1, arr2) print diff1._optinfo diff2 = arr1-arr2 print diff2._optinfo If run, the output looks like this: $ python test_ma_sub.py #Call to np.subtract(arr1, arr2) here __array_finalize__ __array_finalize__ __array_prepare__ __array_finalize__ __array_wrap__ __array_finalize__ {'info': 'test'} #Executing arr1-arr2 here __array_finalize__ {} Currently I have simply downgraded to 1.9.2 to solve the problem for myself, but have been having difficulty figuring out where the difference lies between 1.9.2 and 1.10.0. Thanks, Jeremy

On Mon, Jan 25, 2016 at 10:43 PM, Solbrig,Jeremy < Jeremy.Solbrig@colostate.edu> wrote:
Hello,
Much of what is below was copied from this stack overflow question.
<http://stackoverflow.com/questions/35005569/behavior-of-ufuncs-and-mathemati...>
I am attempting to subclass numpy.ma.MaskedArray. I am currently using Python v2.7.10. The problem discussed below does not occur in Numpy v1.9.2, but does occur in all versions of Numpy v1.10.x.
In all versions of Numpy v1.10.x, using mathematical operators on my subclass behaves differently than using the analogous ufunc. When using the ufunc directly (e.g. np.subtract(arr1, arr2)), __array_prepare__, __array_finalize__, and __array_wrap__ are all called as expected, however, when using the symbolic operator (e.g. arr1-arr2) only __array_finalize__ is called. As a consequence, I lose any information stored in arr._optinfo when a mathematical operator is used.
Here is a code snippet that illustrates the issue.
#!/bin/env python import numpy as npfrom numpy.ma import MaskedArray, nomask class InfoArray(MaskedArray): def __new__(cls, info=None, data=None, mask=nomask, dtype=None, copy=False, subok=True, ndmin=0, fill_value=None, keep_mask=True, hard_mask=None, shrink=True, **kwargs): obj = super(InfoArray, cls).__new__(cls, data=data, mask=mask, dtype=dtype, copy=copy, subok=subok, ndmin=ndmin, fill_value=fill_value, hard_mask=hard_mask, shrink=shrink, **kwargs) obj._optinfo['info'] = info return obj
def __array_prepare__(self, out, context=None): print '__array_prepare__' return super(InfoArray, self).__array_prepare__(out, context)
def __array_wrap__(self, out, context=None): print '__array_wrap__' return super(InfoArray, self).__array_wrap__(out, context)
def __array_finalize__(self, obj): print '__array_finalize__' return super(InfoArray, self).__array_finalize__(obj) if __name__ == "__main__": arr1 = InfoArray('test', data=[1,2,3,4,5,6]) arr2 = InfoArray(data=[0,1,2,3,4,5])
diff1 = np.subtract(arr1, arr2) print diff1._optinfo
diff2 = arr1-arr2 print diff2._optinfo
If run, the output looks like this:
$ python test_ma_sub.py #Call to np.subtract(arr1, arr2) here __array_finalize__ __array_finalize__ __array_prepare__ __array_finalize__ __array_wrap__ __array_finalize__{'info': 'test'}#Executing arr1-arr2 here __array_finalize__{}
Currently I have simply downgraded to 1.9.2 to solve the problem for myself, but have been having difficulty figuring out where the difference lies between 1.9.2 and 1.10.0.
I don't see a difference between 1.9.2 and 1.10.0 in this test, so I suspect it is something else. Could you try 1.10.4 to see if the something else has been fixed? Chuck

On Tue, Jan 26, 2016 at 10:11 AM, Charles R Harris < charlesr.harris@gmail.com> wrote:
On Mon, Jan 25, 2016 at 10:43 PM, Solbrig,Jeremy < Jeremy.Solbrig@colostate.edu> wrote:
Hello,
Much of what is below was copied from this stack overflow question.
<http://stackoverflow.com/questions/35005569/behavior-of-ufuncs-and-mathemati...>
I am attempting to subclass numpy.ma.MaskedArray. I am currently using Python v2.7.10. The problem discussed below does not occur in Numpy v1.9.2, but does occur in all versions of Numpy v1.10.x.
In all versions of Numpy v1.10.x, using mathematical operators on my subclass behaves differently than using the analogous ufunc. When using the ufunc directly (e.g. np.subtract(arr1, arr2)), __array_prepare__, __array_finalize__, and __array_wrap__ are all called as expected, however, when using the symbolic operator (e.g. arr1-arr2) only __array_finalize__ is called. As a consequence, I lose any information stored in arr._optinfo when a mathematical operator is used.
Here is a code snippet that illustrates the issue.
#!/bin/env python import numpy as npfrom numpy.ma import MaskedArray, nomask class InfoArray(MaskedArray): def __new__(cls, info=None, data=None, mask=nomask, dtype=None, copy=False, subok=True, ndmin=0, fill_value=None, keep_mask=True, hard_mask=None, shrink=True, **kwargs): obj = super(InfoArray, cls).__new__(cls, data=data, mask=mask, dtype=dtype, copy=copy, subok=subok, ndmin=ndmin, fill_value=fill_value, hard_mask=hard_mask, shrink=shrink, **kwargs) obj._optinfo['info'] = info return obj
def __array_prepare__(self, out, context=None): print '__array_prepare__' return super(InfoArray, self).__array_prepare__(out, context)
def __array_wrap__(self, out, context=None): print '__array_wrap__' return super(InfoArray, self).__array_wrap__(out, context)
def __array_finalize__(self, obj): print '__array_finalize__' return super(InfoArray, self).__array_finalize__(obj) if __name__ == "__main__": arr1 = InfoArray('test', data=[1,2,3,4,5,6]) arr2 = InfoArray(data=[0,1,2,3,4,5])
diff1 = np.subtract(arr1, arr2) print diff1._optinfo
diff2 = arr1-arr2 print diff2._optinfo
If run, the output looks like this:
$ python test_ma_sub.py #Call to np.subtract(arr1, arr2) here __array_finalize__ __array_finalize__ __array_prepare__ __array_finalize__ __array_wrap__ __array_finalize__{'info': 'test'}#Executing arr1-arr2 here __array_finalize__{}
Currently I have simply downgraded to 1.9.2 to solve the problem for myself, but have been having difficulty figuring out where the difference lies between 1.9.2 and 1.10.0.
I don't see a difference between 1.9.2 and 1.10.0 in this test, so I suspect it is something else. Could you try 1.10.4 to see if the something else has been fixed?
Which is to say, it isn't in the calls to prepare, wrap, and finalize. Now to look in _optinfo. Chuck

Hello Chuck, I receive the same result with 1.10.4. I agree that it looks like __array_prepare__, __array_finalize__, and __array_wrap__ have not been changed. I’m starting to dig into the source again, but focusing on the _MaskedBinaryOperation class to try to understand what is going on there. Jeremy From: NumPy-Discussion <numpy-discussion-bounces@scipy.org<mailto:numpy-discussion-bounces@scipy.org>> on behalf of Charles R Harris <charlesr.harris@gmail.com<mailto:charlesr.harris@gmail.com>> Reply-To: Discussion of Numerical Python <numpy-discussion@scipy.org<mailto:numpy-discussion@scipy.org>> Date: Tuesday, January 26, 2016 at 10:17 AM To: Discussion of Numerical Python <numpy-discussion@scipy.org<mailto:numpy-discussion@scipy.org>> Subject: Re: [Numpy-discussion] Inconsistent behavior for ufuncs in numpy v1.10.X On Tue, Jan 26, 2016 at 10:11 AM, Charles R Harris <charlesr.harris@gmail.com<mailto:charlesr.harris@gmail.com>> wrote: On Mon, Jan 25, 2016 at 10:43 PM, Solbrig,Jeremy <Jeremy.Solbrig@colostate.edu<mailto:Jeremy.Solbrig@colostate.edu>> wrote: Hello, <http://stackoverflow.com/questions/35005569/behavior-of-ufuncs-and-mathemati...> Much of what is below was copied from this stack overflow question. I am attempting to subclass numpy.ma.MaskedArray. I am currently using Python v2.7.10. The problem discussed below does not occur in Numpy v1.9.2, but does occur in all versions of Numpy v1.10.x. In all versions of Numpy v1.10.x, using mathematical operators on my subclass behaves differently than using the analogous ufunc. When using the ufunc directly (e.g. np.subtract(arr1, arr2)), __array_prepare__, __array_finalize__, and __array_wrap__ are all called as expected, however, when using the symbolic operator (e.g. arr1-arr2) only __array_finalize__ is called. As a consequence, I lose any information stored in arr._optinfo when a mathematical operator is used. Here is a code snippet that illustrates the issue. #!/bin/env pythonimport numpy as np from numpy.ma import MaskedArray, nomask class InfoArray(MaskedArray): def __new__(cls, info=None, data=None, mask=nomask, dtype=None, copy=False, subok=True, ndmin=0, fill_value=None, keep_mask=True, hard_mask=None, shrink=True, **kwargs): obj = super(InfoArray, cls).__new__(cls, data=data, mask=mask, dtype=dtype, copy=copy, subok=subok, ndmin=ndmin, fill_value=fill_value, hard_mask=hard_mask, shrink=shrink, **kwargs) obj._optinfo['info'] = info return obj def __array_prepare__(self, out, context=None): print '__array_prepare__' return super(InfoArray, self).__array_prepare__(out, context) def __array_wrap__(self, out, context=None): print '__array_wrap__' return super(InfoArray, self).__array_wrap__(out, context) def __array_finalize__(self, obj): print '__array_finalize__' return super(InfoArray, self).__array_finalize__(obj)if __name__ == "__main__": arr1 = InfoArray('test', data=[1,2,3,4,5,6]) arr2 = InfoArray(data=[0,1,2,3,4,5]) diff1 = np.subtract(arr1, arr2) print diff1._optinfo diff2 = arr1-arr2 print diff2._optinfo If run, the output looks like this: $ python test_ma_sub.py #Call to np.subtract(arr1, arr2) here __array_finalize__ __array_finalize__ __array_prepare__ __array_finalize__ __array_wrap__ __array_finalize__ {'info': 'test'}#Executing arr1-arr2 here __array_finalize__ {} Currently I have simply downgraded to 1.9.2 to solve the problem for myself, but have been having difficulty figuring out where the difference lies between 1.9.2 and 1.10.0. I don't see a difference between 1.9.2 and 1.10.0 in this test, so I suspect it is something else. Could you try 1.10.4 to see if the something else has been fixed? Which is to say, it isn't in the calls to prepare, wrap, and finalize. Now to look in _optinfo. Chuck

On Tue, Jan 26, 2016 at 10:27 AM, Solbrig,Jeremy < Jeremy.Solbrig@colostate.edu> wrote:
Hello Chuck,
I receive the same result with 1.10.4. I agree that it looks like __array_prepare__, __array_finalize__, and __array_wrap__ have not been changed. I’m starting to dig into the source again, but focusing on the _MaskedBinaryOperation class to try to understand what is going on there.
Jeremy
From: NumPy-Discussion <numpy-discussion-bounces@scipy.org> on behalf of Charles R Harris <charlesr.harris@gmail.com> Reply-To: Discussion of Numerical Python <numpy-discussion@scipy.org> Date: Tuesday, January 26, 2016 at 10:17 AM To: Discussion of Numerical Python <numpy-discussion@scipy.org> Subject: Re: [Numpy-discussion] Inconsistent behavior for ufuncs in numpy v1.10.X
On Tue, Jan 26, 2016 at 10:11 AM, Charles R Harris < charlesr.harris@gmail.com> wrote:
On Mon, Jan 25, 2016 at 10:43 PM, Solbrig,Jeremy < Jeremy.Solbrig@colostate.edu> wrote:
Hello,
Much of what is below was copied from this stack overflow question.
<http://stackoverflow.com/questions/35005569/behavior-of-ufuncs-and-mathemati...>
I am attempting to subclass numpy.ma.MaskedArray. I am currently using Python v2.7.10. The problem discussed below does not occur in Numpy v1.9.2, but does occur in all versions of Numpy v1.10.x.
In all versions of Numpy v1.10.x, using mathematical operators on my subclass behaves differently than using the analogous ufunc. When using the ufunc directly (e.g. np.subtract(arr1, arr2)), __array_prepare__, __array_finalize__, and __array_wrap__ are all called as expected, however, when using the symbolic operator (e.g. arr1-arr2) only __array_finalize__ is called. As a consequence, I lose any information stored in arr._optinfo when a mathematical operator is used.
Here is a code snippet that illustrates the issue.
#!/bin/env pythonimport numpy as npfrom numpy.ma import MaskedArray, nomask class InfoArray(MaskedArray): def __new__(cls, info=None, data=None, mask=nomask, dtype=None, copy=False, subok=True, ndmin=0, fill_value=None, keep_mask=True, hard_mask=None, shrink=True, **kwargs): obj = super(InfoArray, cls).__new__(cls, data=data, mask=mask, dtype=dtype, copy=copy, subok=subok, ndmin=ndmin, fill_value=fill_value, hard_mask=hard_mask, shrink=shrink, **kwargs) obj._optinfo['info'] = info return obj
def __array_prepare__(self, out, context=None): print '__array_prepare__' return super(InfoArray, self).__array_prepare__(out, context)
def __array_wrap__(self, out, context=None): print '__array_wrap__' return super(InfoArray, self).__array_wrap__(out, context)
def __array_finalize__(self, obj): print '__array_finalize__' return super(InfoArray, self).__array_finalize__(obj)if __name__ == "__main__": arr1 = InfoArray('test', data=[1,2,3,4,5,6]) arr2 = InfoArray(data=[0,1,2,3,4,5])
diff1 = np.subtract(arr1, arr2) print diff1._optinfo
diff2 = arr1-arr2 print diff2._optinfo
If run, the output looks like this:
$ python test_ma_sub.py #Call to np.subtract(arr1, arr2) here __array_finalize__ __array_finalize__ __array_prepare__ __array_finalize__ __array_wrap__ __array_finalize__{'info': 'test'}#Executing arr1-arr2 here __array_finalize__{}
Currently I have simply downgraded to 1.9.2 to solve the problem for myself, but have been having difficulty figuring out where the difference lies between 1.9.2 and 1.10.0.
I don't see a difference between 1.9.2 and 1.10.0 in this test, so I suspect it is something else. Could you try 1.10.4 to see if the something else has been fixed?
Which is to say, it isn't in the calls to prepare, wrap, and finalize. Now to look in _optinfo.
Please open an issue on github, the mailing list is not a good place to deal with this. I've got a bisect script running, so we should soon know where the change occurred. Chuck

Will do. Thanks for looking into this! From: NumPy-Discussion <numpy-discussion-bounces@scipy.org<mailto:numpy-discussion-bounces@scipy.org>> on behalf of Charles R Harris <charlesr.harris@gmail.com<mailto:charlesr.harris@gmail.com>> Reply-To: Discussion of Numerical Python <numpy-discussion@scipy.org<mailto:numpy-discussion@scipy.org>> Date: Tuesday, January 26, 2016 at 10:35 AM To: Discussion of Numerical Python <numpy-discussion@scipy.org<mailto:numpy-discussion@scipy.org>> Subject: Re: [Numpy-discussion] Inconsistent behavior for ufuncs in numpy v1.10.X On Tue, Jan 26, 2016 at 10:27 AM, Solbrig,Jeremy <Jeremy.Solbrig@colostate.edu<mailto:Jeremy.Solbrig@colostate.edu>> wrote: Hello Chuck, I receive the same result with 1.10.4. I agree that it looks like __array_prepare__, __array_finalize__, and __array_wrap__ have not been changed. I’m starting to dig into the source again, but focusing on the _MaskedBinaryOperation class to try to understand what is going on there. Jeremy From: NumPy-Discussion <numpy-discussion-bounces@scipy.org<mailto:numpy-discussion-bounces@scipy.org>> on behalf of Charles R Harris <charlesr.harris@gmail.com<mailto:charlesr.harris@gmail.com>> Reply-To: Discussion of Numerical Python <numpy-discussion@scipy.org<mailto:numpy-discussion@scipy.org>> Date: Tuesday, January 26, 2016 at 10:17 AM To: Discussion of Numerical Python <numpy-discussion@scipy.org<mailto:numpy-discussion@scipy.org>> Subject: Re: [Numpy-discussion] Inconsistent behavior for ufuncs in numpy v1.10.X On Tue, Jan 26, 2016 at 10:11 AM, Charles R Harris <charlesr.harris@gmail.com<mailto:charlesr.harris@gmail.com>> wrote: On Mon, Jan 25, 2016 at 10:43 PM, Solbrig,Jeremy <Jeremy.Solbrig@colostate.edu<mailto:Jeremy.Solbrig@colostate.edu>> wrote: Hello, <http://stackoverflow.com/questions/35005569/behavior-of-ufuncs-and-mathemati...> Much of what is below was copied from this stack overflow question. I am attempting to subclass numpy.ma.MaskedArray. I am currently using Python v2.7.10. The problem discussed below does not occur in Numpy v1.9.2, but does occur in all versions of Numpy v1.10.x. In all versions of Numpy v1.10.x, using mathematical operators on my subclass behaves differently than using the analogous ufunc. When using the ufunc directly (e.g. np.subtract(arr1, arr2)), __array_prepare__, __array_finalize__, and __array_wrap__ are all called as expected, however, when using the symbolic operator (e.g. arr1-arr2) only __array_finalize__ is called. As a consequence, I lose any information stored in arr._optinfo when a mathematical operator is used. Here is a code snippet that illustrates the issue. #!/bin/env pythonimport numpy as np from numpy.ma import MaskedArray, nomask class InfoArray(MaskedArray): def __new__(cls, info=None, data=None, mask=nomask, dtype=None, copy=False, subok=True, ndmin=0, fill_value=None, keep_mask=True, hard_mask=None, shrink=True, **kwargs): obj = super(InfoArray, cls).__new__(cls, data=data, mask=mask, dtype=dtype, copy=copy, subok=subok, ndmin=ndmin, fill_value=fill_value, hard_mask=hard_mask, shrink=shrink, **kwargs) obj._optinfo['info'] = info return obj def __array_prepare__(self, out, context=None): print '__array_prepare__' return super(InfoArray, self).__array_prepare__(out, context) def __array_wrap__(self, out, context=None): print '__array_wrap__' return super(InfoArray, self).__array_wrap__(out, context) def __array_finalize__(self, obj): print '__array_finalize__' return super(InfoArray, self).__array_finalize__(obj)if __name__ == "__main__": arr1 = InfoArray('test', data=[1,2,3,4,5,6]) arr2 = InfoArray(data=[0,1,2,3,4,5]) diff1 = np.subtract(arr1, arr2) print diff1._optinfo diff2 = arr1-arr2 print diff2._optinfo If run, the output looks like this: $ python test_ma_sub.py #Call to np.subtract(arr1, arr2) here __array_finalize__ __array_finalize__ __array_prepare__ __array_finalize__ __array_wrap__ __array_finalize__ {'info': 'test'}#Executing arr1-arr2 here __array_finalize__ {} Currently I have simply downgraded to 1.9.2 to solve the problem for myself, but have been having difficulty figuring out where the difference lies between 1.9.2 and 1.10.0. I don't see a difference between 1.9.2 and 1.10.0 in this test, so I suspect it is something else. Could you try 1.10.4 to see if the something else has been fixed? Which is to say, it isn't in the calls to prepare, wrap, and finalize. Now to look in _optinfo. Please open an issue on github, the mailing list is not a good place to deal with this. I've got a bisect script running, so we should soon know where the change occurred. Chuck

On Di, 2016-01-26 at 17:27 +0000, Solbrig,Jeremy wrote:
Hello Chuck,
I receive the same result with 1.10.4. I agree that it looks like __array_prepare__, __array_finalize__, and __array_wrap__ have not been changed. I’m starting to dig into the source again, but focusing on the _MaskedBinaryOperation class to try to understand what is going on there.
Well, there was definitely a change in that code that will cause this, i.e. the code block: if isinstance(b, MaskedArray): if isinstance(a, MaskedArray): result._update_from(a) else: result._update_from(b) elif isinstance(a, MaskedArray): result._update_from(a) was changed to something like: masked_result._update_from(result) My guess is almost that this fixed some other bug (but you should probably check git blame to see why it was put in). It might be that _optinfo should be handled more specifically. It seems like a very weird feature to me though when the info is always copied from the left operand... Is _optinfo even *documented* to exist? Because frankly, unless it is used far more, and the fact that it is hidden away with an underscore, I am not sure we should prioritize that it would keep working, considering that I am unsure that it ever did something very elegantly. - Sebastian
Jeremy
From: NumPy-Discussion <numpy-discussion-bounces@scipy.org> on behalf of Charles R Harris <charlesr.harris@gmail.com> Reply-To: Discussion of Numerical Python <numpy-discussion@scipy.org> Date: Tuesday, January 26, 2016 at 10:17 AM To: Discussion of Numerical Python <numpy-discussion@scipy.org> Subject: Re: [Numpy-discussion] Inconsistent behavior for ufuncs in numpy v1.10.X
On Tue, Jan 26, 2016 at 10:11 AM, Charles R Harris < charlesr.harris@gmail.com> wrote:
On Mon, Jan 25, 2016 at 10:43 PM, Solbrig,Jeremy < Jeremy.Solbrig@colostate.edu> wrote:
Hello,
Much of what is below was copied from this stack overflow question. I am attempting to subclass numpy.ma.MaskedArray. I am currently using Python v2.7.10. The problem discussed below does not occur in Numpy v1.9.2, but does occur in all versions of Numpy v1.10.x. In all versions of Numpy v1.10.x, using mathematical operators on my subclass behaves differently than using the analogous ufunc. When using the ufunc directly (e.g. np.subtract(arr1, arr2)), __array_prepare__, __array_finalize__, and __array_wrap__ are all called as expected, however, when using the symbolic operator (e.g. arr1-arr2) only __array_finalize__ is called. As a consequence, I lose any information stored in arr._optinfo when a mathematical operator is used. Here is a code snippet that illustrates the issue.
#!/bin/env pythonimport numpy as np from numpy.ma import MaskedArray, nomask
class InfoArray(MaskedArray): def __new__(cls, info=None, data=None, mask=nomask, dtype=None, copy=False, subok=True, ndmin=0, fill_value=None, keep_mask=True, hard_mask=None, shrink=True, **kwargs): obj = super(InfoArray, cls).__new__(cls, data=data, mask=mask, dtype=dtype, copy=copy, subok=subok, ndmin=ndmin, fill_value=fill_value, hard_mask=hard_mask, shrink=shrink, **kwargs) obj._optinfo['info'] = info return obj
def __array_prepare__(self, out, context=None): print '__array_prepare__' return super(InfoArray, self).__array_prepare__(out, context)
def __array_wrap__(self, out, context=None): print '__array_wrap__' return super(InfoArray, self).__array_wrap__(out, context)
def __array_finalize__(self, obj): print '__array_finalize__' return super(InfoArray, self).__array_finalize__(obj)if __name__ == "__main__": arr1 = InfoArray('test', data=[1,2,3,4,5,6]) arr2 = InfoArray(data=[0,1,2,3,4,5])
diff1 = np.subtract(arr1, arr2) print diff1._optinfo
diff2 = arr1-arr2 print diff2._optinfo If run, the output looks like this:
$ python test_ma_sub.py #Call to np.subtract(arr1, arr2) here __array_finalize__ __array_finalize__ __array_prepare__ __array_finalize__ __array_wrap__ __array_finalize__ {'info': 'test'}#Executing arr1-arr2 here __array_finalize__ {} Currently I have simply downgraded to 1.9.2 to solve the problem for myself, but have been having difficulty figuring out where the difference lies between 1.9.2 and 1.10.0.
I don't see a difference between 1.9.2 and 1.10.0 in this test, so I suspect it is something else. Could you try 1.10.4 to see if the something else has been fixed?
Which is to say, it isn't in the calls to prepare, wrap, and finalize. Now to look in _optinfo.
Chuck _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org https://mail.scipy.org/mailman/listinfo/numpy-discussion

The problem isn’t specifically with _optinfo. _optinfo losing information is just a symptom of the fact that __array_prepare__, __array_wrap__, and __array_finalize__ do not appear to be working as documented. So far as I can tell, there is no way to access attributes of subclasses when using mathematical operators so it is impossible to maintain subclasses that contain additional attributes. On 1/26/16, 10:45 AM, "NumPy-Discussion on behalf of Sebastian Berg" <numpy-discussion-bounces@scipy.org on behalf of sebastian@sipsolutions.net> wrote:
was changed to something like:
masked_result._update_from(result)
My guess is almost that this fixed some other bug (but you should probably check git blame to see why it was put in). It might be that _optinfo should be handled more specifically. It seems like a very weird feature to me though when the info is always copied from the left operand...

New issue submitted here: https://github.com/numpy/numpy/issues/7122 I suggest moving this discussion there. On 1/26/16, 10:49 AM, "NumPy-Discussion on behalf of Solbrig,Jeremy" <numpy-discussion-bounces@scipy.org on behalf of Jeremy.Solbrig@colostate.edu> wrote:
The problem isn’t specifically with _optinfo. _optinfo losing information is just a symptom of the fact that __array_prepare__, __array_wrap__, and __array_finalize__ do not appear to be working as documented. So far as I can tell, there is no way to access attributes of subclasses when using mathematical operators so it is impossible to maintain subclasses that contain additional attributes.
On 1/26/16, 10:45 AM, "NumPy-Discussion on behalf of Sebastian Berg" <numpy-discussion-bounces@scipy.org on behalf of sebastian@sipsolutions.net> wrote:
was changed to something like:
masked_result._update_from(result)
My guess is almost that this fixed some other bug (but you should probably check git blame to see why it was put in). It might be that _optinfo should be handled more specifically. It seems like a very weird feature to me though when the info is always copied from the left operand...
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On Tue, Jan 26, 2016 at 10:45 AM, Sebastian Berg <sebastian@sipsolutions.net
wrote:
On Di, 2016-01-26 at 17:27 +0000, Solbrig,Jeremy wrote:
Hello Chuck,
I receive the same result with 1.10.4. I agree that it looks like __array_prepare__, __array_finalize__, and __array_wrap__ have not been changed. I’m starting to dig into the source again, but focusing on the _MaskedBinaryOperation class to try to understand what is going on there.
Well, there was definitely a change in that code that will cause this, i.e. the code block:
if isinstance(b, MaskedArray): if isinstance(a, MaskedArray): result._update_from(a) else: result._update_from(b) elif isinstance(a, MaskedArray): result._update_from(a)
was changed to something like:
masked_result._update_from(result)
That looks like it, 3c6b6baba, #3907 <https://github.com/numpy/numpy/pull/3907>. That's old... <snip> Chuck
participants (3)
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Charles R Harris
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Sebastian Berg
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Solbrig,Jeremy