[SciPy-User] numpy.array of mixed type.

Éric Depagne edepagne@lcogt....
Thu Apr 22 10:16:57 CDT 2010


Le mercredi 21 avril 2010 17:27:14, Charles R Harris a écrit :
> On Wed, Apr 21, 2010 at 9:49 AM, Éric Depagne <edepagne@lcogt.net> wrote:
> > Hi.
> >
> > I'd like to create an array that would contain data of two different
> > types: str and float64.
> >
> > I've created a dtype accordingly :
> > dt = dtype({'names': ['Type', 'Chisquare'], 'formats': ['S8', float64]})
> > then, I initialise my array as follow:
> > temp = zeros ((1,1), dtype = dt)
> >
> > that gives me the following:
> > array([[('', 0.0)]],
> >      dtype=[('Type', '|S8'), ('Chisquare', '<f8')])
> >
> > which is almost good.
> >
> > I'd like to know if it is possible instead of having an array with one
> > column
> > that will contain a tuple, to create an array with two columns,  the
> > first column being a str and the second a float.
> 
> It's not a tuple, it is just displayed that way, it is more like a packed c
> structure. But no, you can't have *actual* ndarray columns of different
> types. What problem do you have with using the dtype?

I tried to sort my array along the Chisquare column and could not.
temp.sort (axis = 0) sorts along the column named Type, but I can't find a way 
to sort along Chisquare. Is it possible?

Éric
> 
> Chuck
> 

-- 
Un clavier azerty en vaut deux
----------------------------------------------------------
Éric Depagne                            edepagne@lcogt.net
Las Cumbres Observatory 
6740 Cortona Dr
Goleta CA, 93117
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