[Numpy-discussion] ANN: NumPy 1.5.0 beta 2

[Christoph Gohlke]

On 8/17/2010 9:56 PM, Charles R Harris wrote:
>
>
> On Tue, Aug 17, 2010 at 9:11 PM, Christoph Gohlke <cgohlke@uci.edu
> <mailto:cgohlke@uci.edu>> wrote:
>
>
>
>     On 8/17/2010 1:02 PM, Charles R Harris wrote:
>     >
>     >
>     >  On Tue, Aug 17, 2010 at 1:38 PM, Christoph Gohlke <cgohlke@uci.edu
>     <mailto:cgohlke@uci.edu>
>     >  <mailto:cgohlke@uci.edu <mailto:cgohlke@uci.edu>>> wrote:
>     >
>     >
>     >
>     >      On 8/17/2010 8:23 AM, Ralf Gommers wrote:
>     >
>     >          I am pleased to announce the availability of the second
>     beta of
>     >          NumPy
>     >          1.5.0. This will be the first NumPy release to include
>     support for
>     >          Python 3, as well as for Python 2.7.
>     >
>     >          Please try this beta and report any problems on the NumPy
>     >          mailing list.
>     >          Especially with Python 3 testing will be very useful. On Linux
>     >          and OS X
>     >          building from source should be straightforward, for
>     Windows a binary
>     >          installer is provided. There is one important known issue
>     on Windows
>     >          left, in fromfile and tofile (ticket 1583).
>     >
>     >          Binaries, sources and release notes can be found at
>     >  https://sourceforge.net/projects/numpy/files/
>     >  <https://sourceforge.net/projects/numpy/files/>
>     >
>     >          Enjoy,
>     >          Ralf
>     >
>     >
>     >      NumPy 1.5.0 beta 2 built with msvc9/mkl for Python 2.7 and 3.1 (32
>     >      and 64 bit) still reports many (> 200) warnings and three
>     known test
>     >      failures/errors. Nothing serious, but it would be nice to clean up
>     >      before the final release.
>     >
>     >      The warnings are of the type "Warning: invalid value
>     encountered in"
>     >      for the functions reduce, fmax, fmin, logaddexp, maximum, greater,
>     >      less_equal, greater_equal, absolute, and others. I do not see
>     any of
>     >      these warnings in the msvc9 builds of numpy 1.4.1.
>     >
>     >
>     >  The warnings were accidentally turned off for earlier versions of
>     Numpy.
>     >  I expect these warnings are related to nans and probably due to
>     problems
>     >  with isnan or some such. Can you take a closer look? The fmax function
>     >  should be easy to check out.
>     >
>     >  <sniip>
>     >
>     >  Chuck
>     >
>
>
>     Thanks for the hint. Warnings are issued in the test_umath test_*nan*
>     functions. The problem can be condensed to this statement:
>
>     > >> numpy.array([numpy.nan]) > 0
>     Warning: invalid value encountered in greater
>     array([False], dtype=bool)
>
>
>     When using msvc, ordered comparisons involving NaN raise an exception
>     [1], i.e. set the 'invalid' x87 status bit, which leads to the warning
>     being printed. I don't know if this violates IEEE 754 or C99 standards
>     but it does not happen with the gcc builds. Maybe
>     seterr(invalid='ignore') could be added to the test_*nan* functions?
>
>     [1] http://msdn.microsoft.com/en-us/library/e7s85ffb%28v=VS.90%29.aspx
>
>
> OK, this does seem to be the standard. For instance
>
> The isless macro determines whether its first argument is less than its
> second
> argument. The value of isless(x, y) is always equal to (x) < (y); however,
> unlike (x) < (y), isless(x, y) does not raise the ‘‘invalid’’ floating-point
> exception when x and y are unordered.
>
> There are other macros for the rest of the comparisons. Can you check if
> MSVC has these macros available?
>

MSVC doesn't have these macros. It should not be too difficult to define 
them according to 
http://code.google.com/p/v8/source/browse/branches/bleeding_edge/src/platform-win32.cc

int isless(double x, double y) {
   return isnan(x) || isnan(y) ? 0 : x < y;
}


int isgreater(double x, double y) {
   return isnan(x) || isnan(y) ? 0 : x > y;
}

--
Christoph