[Numpy-discussion] Help needed with the priority of 0d-arrays and np.scalars

Pierre GM pgmdevlist@gmail....
Tue Sep 30 16:36:59 CDT 2008

On Tuesday 30 September 2008 17:18:13 Travis E. Oliphant wrote:

> Hmm...  I'm not 100% sure off the top of my head, but I would say that
> 0d arrays should determine the type coercion if any and the returned
> thing should be a numpy scalar.

I'm afraid I don't understand. According to you, a 0d array should always have 
the priority on a numpy scalar, right ? That doesn't seem to be the case:

ma.masked is a 0d ndarray with a np.float64 dtype and a __array__priority__ of 
15. It implements special __mul__ and __rmul__ methods.

The multiplication `ma.masked * np.float64(1)` calls `ma.masked.__mul__`, as 
it should.
The multiplication `np.float64(1)*ma.masked` doesn't call `ma.masked.__mul__` 
nor `ma.masked.__rmul__`.
However,  `np.float32(1)*ma.masked` does.

How could I force `np.float64(1)*ma.masked` to call the proper method ?

More information about the Numpy-discussion mailing list