[Numpy-discussion] numarray bug: dot product between 2x2 and 3x2x3 on Mac different from PC
haase at msg.ucsf.edu
Mon Jul 17 14:26:33 CDT 2006
On Monday 17 July 2006 12:10, Travis Oliphant wrote:
> Sebastian Haase wrote:
> > Traceback (most recent call last):
> > File "<input>", line 1, in ?
> > TypeError: array cannot be safely cast to required type
> >>>> dd=d.astype(N.float32)
> >>>> N.dot(dd,ccc)
> > [[[ 1. 1. 1.]
> > [ 1. 1. 1.]
> > [ 1. 1. 1.]]
> > [[ 2. 2. 2.]
> > [ 2. 2. 2.]
> > [ 2. 2. 2.]]]
> > The TypeError looks like a numpy bug !
> I don't see why this is a bug. You are trying to coerce a 32-bit
> integer to a 32-bit float. That is going to lose precision and so you
> get the error indicated.
In numarray I do not get an error. Would the error go away if I had 64 bit
float !? It seems though that having ones and twos in an int array should
fit just fine into a float32 array !?
- Sebastian Haase
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