On 11.10.2013, at 01:19, Julian Taylor wrote:
>>>
>>>Yeah, unless the current behaviour is actually broken or redundant in
>>>some way, we're not going to switch from one perfectly good convention
>>>to another perfectly good convention and break everyone's code in the
>>>process
On 10.10.2013, at 19:27, David Goldsmith wrote:
> On Wed, Oct 9, 2013 at 7:48 PM, Bernhard Spinnler
> wrote:
> > Hi Richard,
> >
> > Ah, I searched the list but didn't find those posts before?
> >
> > I can easily imagine that correlation is defined
It seems to me that Wolfram is following yet another path. From
http://mathworld.wolfram.com/Autocorrelation.html and more importantly
http://mathworld.wolfram.com/Cross-Correlation.html, equation (5):
z_mathworld[k] = sum_n conj(a[n]) * v[n+k]
= conj( sum_n a[n] * conj(v[n+k]) )
mains use different conventions here? Are there some
> references to back up one stance or another?
>
> But all else being equal, I'm guessing there'll be far more appetite for
> updating the documentation than the code.
>
> Regards,
> Richard Ha
The numpy.correlate documentation says:
correlate(a, v) = z[k] = sum_n a[n] * conj(v[n+k])
In [1]: a = [1, 2]
In [2]: v = [2, 1j]
In [3]: z = correlate(a, v, 'full')
In [4]: z
Out[4]: array([ 0.-1.j, 2.-2.j, 4.+0.j])
However, according to the documentation, z should be
z[-1
I have problems to get a piece of code to work with a new numpy/scipy version.
The code essentially sets up a matrix Ryy and a vector Rya and solves the
system of linear equations Ryy*c = Rya for c. Then it checks whether the
resulting vector c satisfies the equation: Ryy*c must be equal to Rya.
