Re: [Numpy-discussion] the difference between "+" and np.add?

2012-11-23 Thread Chris Barker - NOAA Federal
On Thu, Nov 22, 2012 at 6:20 AM, Francesc Alted wrote: > As Nathaniel said, there is not a difference in terms of *what* is > computed. However, the methods that you suggested actually differ on > *how* they are computed, and that has dramatic effects on the time > used. For example: > > In []:

Re: [Numpy-discussion] Unexpected RuntimeWarning

2012-11-23 Thread Charles R Harris
On Fri, Nov 23, 2012 at 4:38 AM, Bob Dowling wrote: > I have a simple function defined in the following snippet: > > --- start --- > import numpy > > def chebyshev(x, m): > '''Calculates Chebyshev functions of the first kind using the > trigonometric identities.''' > > theta = numpy.w

Re: [Numpy-discussion] When are 0-d arrays writeable?

2012-11-23 Thread Charles R Harris
On Fri, Nov 23, 2012 at 7:53 AM, Sebastian Berg wrote: > On Fri, 2012-11-23 at 10:49 +, Nathaniel Smith wrote: > > On 23 Nov 2012 03:34, "Charles R Harris" > > wrote: > > > > > > Examples, > > > > > > In [13]: ones(()).flags.writeable > > > Out[13]: True > > > > > > In [14]: (-ones(())).flags

[Numpy-discussion] [ANN] Stochastic programming and optimization addon for FuncDesigner v. 0.421

2012-11-23 Thread Dmitrey
hi all, I'm glad to inform you that stochastic programming and optimization addon for FuncDesigner v. 0.421 has been released. Now you can use gradient-based solvers for numerical optimization, such as ALGENCAN, IPOPT, ralg, gsubg etc. Usually they work faster than derivative-free (such as scip

Re: [Numpy-discussion] When are 0-d arrays writeable?

2012-11-23 Thread Sebastian Berg
On Fri, 2012-11-23 at 10:49 +, Nathaniel Smith wrote: > On 23 Nov 2012 03:34, "Charles R Harris" > wrote: > > > > Examples, > > > > In [13]: ones(()).flags.writeable > > Out[13]: True > > > > In [14]: (-ones(())).flags.writeable > > Out[14]: False > > > > In [15]: (-1*ones(())).flags.writeable

Re: [Numpy-discussion] Unexpected RuntimeWarning

2012-11-23 Thread Bob Dowling
> You may want to use this: > http://docs.scipy.org/doc/numpy/reference/generated/numpy.piecewise.html Thank you. That's just what I needed. Works a treat: --- start --- import numpy def chebyshev(x, m): '''Calculates Chebyshev functions of the first kind using the trigonometric identi

Re: [Numpy-discussion] Unexpected RuntimeWarning

2012-11-23 Thread Pauli Virtanen
Bob Dowling cam.ac.uk> writes: [clip] > I'm guessing that numpy.where() is evaluating the complete arccos and > arccosh arrays and therefore getting invalid arguments. > > Now, I can turn off the warnings with numpy.seterr(invalid='ignore') but > that's not what I would regard as good practice.

[Numpy-discussion] Unexpected RuntimeWarning

2012-11-23 Thread Bob Dowling
I have a simple function defined in the following snippet: --- start --- import numpy def chebyshev(x, m): '''Calculates Chebyshev functions of the first kind using the trigonometric identities.''' theta = numpy.where( numpy.abs(x)<=1.0, numpy.arccos(x), n

Re: [Numpy-discussion] When are 0-d arrays writeable?

2012-11-23 Thread Nathaniel Smith
On 23 Nov 2012 03:34, "Charles R Harris" wrote: > > Examples, > > In [13]: ones(()).flags.writeable > Out[13]: True > > In [14]: (-ones(())).flags.writeable > Out[14]: False > > In [15]: (-1*ones(())).flags.writeable > Out[15]: False > > In [16]: (1 + ones(())).flags.writeable > Out[16]: False > >