Hello,
I have a quick question that I'm hoping will improve my numpy understanding. I noticed some behavior when using float64 to convert a matrix type that I didn't expect: In [35]: b1 = array([1.0]) In [36]: float64(b1) Out[36]: 1.0 In [37]: b2 = array([1.0, 2.0]) In [38]: float64(b2) Out[38]: array([ 1., 2.]) I didn't expect calling float64 would convert b1 to a scalar. Seems like an inconsistency. I assume this is intentional, as someone would have noticed it a long time ago if not, so could someone explain the reasoning behind it? (or point me to a source that will help?) Thanks! --Hoyt -- +++++++++++++++++++++++++++++++++++ Hoyt Koepke UBC Department of Computer Science http://www.cs.ubc.ca/~hoytak/ [hidden email] +++++++++++++++++++++++++++++++++++ _______________________________________________ Numpy-discussion mailing list [hidden email] http://projects.scipy.org/mailman/listinfo/numpy-discussion |
On Tue, Apr 29, 2008 at 12:28 AM, Hoyt Koepke <[hidden email]> wrote: Hello, It's inconsistent and looks like a bug: In [4]: float32(array([[[1]]])) Out[4]: array([[[ 1.]]], dtype=float32) In [5]: float64(array([[[1]]])) Out[5]: 1.0 Float64 is a bit special because it starts as the python float. Maybe Travis can say what the differences are. Chuck _______________________________________________ Numpy-discussion mailing list [hidden email] http://projects.scipy.org/mailman/listinfo/numpy-discussion |
To be honest, this doesn't seem justifiable.
Where it got me is interfacing with c-code that expected a 1d array, and I was calling it with arrays of varying length. I was using this to ensure the proper typing; however, when the array was length 1, the program crashed... Should I file a bug report? --Hoyt On Mon, Apr 28, 2008 at 11:51 PM, Charles R Harris <[hidden email]> wrote: > > > > On Tue, Apr 29, 2008 at 12:28 AM, Hoyt Koepke <[hidden email]> wrote: > > Hello, > > > > I have a quick question that I'm hoping will improve my numpy > > understanding. I noticed some behavior when using float64 to convert > > a matrix type that I didn't expect: > > > > > > In [35]: b1 = array([1.0]) > > > > In [36]: float64(b1) > > Out[36]: 1.0 > > > > In [37]: b2 = array([1.0, 2.0]) > > > > In [38]: float64(b2) > > Out[38]: array([ 1., 2.]) > > > > > > I didn't expect calling float64 would convert b1 to a scalar. Seems > > like an inconsistency. I assume this is intentional, as someone would > > have noticed it a long time ago if not, so could someone explain the > > reasoning behind it? (or point me to a source that will help?) > > > > It's inconsistent and looks like a bug: > > In [4]: float32(array([[[1]]])) > Out[4]: array([[[ 1.]]], dtype=float32) > > In [5]: float64(array([[[1]]])) > Out[5]: 1.0 > > Float64 is a bit special because it starts as the python float. Maybe Travis > can say what the differences are. > > Chuck > > > > _______________________________________________ > Numpy-discussion mailing list > [hidden email] > http://projects.scipy.org/mailman/listinfo/numpy-discussion > > -- +++++++++++++++++++++++++++++++++++ Hoyt Koepke UBC Department of Computer Science http://www.cs.ubc.ca/~hoytak/ [hidden email] +++++++++++++++++++++++++++++++++++ _______________________________________________ Numpy-discussion mailing list [hidden email] http://projects.scipy.org/mailman/listinfo/numpy-discussion |
On Thu, May 1, 2008 at 7:49 PM, Hoyt Koepke <[hidden email]> wrote: To be honest, this doesn't seem justifiable. I already did, it's ticket #764. Chuck _______________________________________________ Numpy-discussion mailing list [hidden email] http://projects.scipy.org/mailman/listinfo/numpy-discussion |
Okay, thanks! I didn't check.
--Hoyt On Thu, May 1, 2008 at 7:00 PM, Charles R Harris <[hidden email]> wrote: > > > > On Thu, May 1, 2008 at 7:49 PM, Hoyt Koepke <[hidden email]> wrote: > > To be honest, this doesn't seem justifiable. > > > > Where it got me is interfacing with c-code that expected a 1d array, > > and I was calling it with arrays of varying length. I was using this > > to ensure the proper typing; however, when the array was length 1, the > > program crashed... > > > > Should I file a bug report? > > > > > > I already did, it's ticket #764. > > Chuck > > > _______________________________________________ > Numpy-discussion mailing list > [hidden email] > http://projects.scipy.org/mailman/listinfo/numpy-discussion > > -- +++++++++++++++++++++++++++++++++++ Hoyt Koepke UBC Department of Computer Science http://www.cs.ubc.ca/~hoytak/ [hidden email] +++++++++++++++++++++++++++++++++++ _______________________________________________ Numpy-discussion mailing list [hidden email] http://projects.scipy.org/mailman/listinfo/numpy-discussion |
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