Yes.
Your first eigenvalue is effectively 0, the values you see are just noise.
Different implementations produce different noise.
As for the signs ot the eigenvector components, which direction is + or - X is
arbitrary. Different implementations follow different conventions as to which
is wh
On Tue, 19 Feb 2008 17:10:10 -0600
"Sameer DCosta" <[EMAIL PROTECTED]> wrote:
> Hi,
>
> I'm getting a segfault when using python objects with
>record arrays.
> The code (below) basically assigns a single datetime
>object to a slice
> of a column in the record array and then python
>segfaults
Hi,
The results are OK, they are very close. Your matrix is almost singular, is
badly conditionned, ... But the results are very close is you check them in
a relative way. 3.84433376e-03 or -6.835301757686207E-4 is the same compared
to 2.76980401e+13
Matthieu
2008/2/20, [EMAIL PROTECTED] <[EMAIL
hi
i was calculating eigenvalues and eigenvectors for a covariancematrix
using numpy
adjfaces=matrix(adjarr)
faces_trans=adjfaces.transpose()
covarmat=adjfaces*faces_trans
evalues,evect=eigh(covarmat)
for a sample covarmat like
[[ 1.69365981e+13 , -5.44960784e+12, -9.00346400e+12 , -2.48352625e
Hi,
I would like to know what the UI should be for numscons wrt to
compilation / link flags. This is an issue which has confused many
people with distutils, and something we can fix with numscons. Several
approaches are possible for numscons, but I was wondering about the
preferred behavio
On Feb 19, 2008 2:20 PM, Stefan van der Walt <[EMAIL PROTECTED]> wrote:
> On Tue, Feb 19, 2008 at 01:50:04PM -0700, Charles R Harris wrote:
> > And here I thought you were going to fix that. Deleting the "blahs"
> isn't a
> > fix, it's a coverup. Now there is no extended documentation at all.
>
>
Hi,
I'm getting a segfault when using python objects with record arrays.
The code (below) basically assigns a single datetime object to a slice
of a column in the record array and then python segfaults as soon as I
try to access those array values. I'm using the latest svn version of
numpy compile
On Tue, Feb 19, 2008 at 01:50:04PM -0700, Charles R Harris wrote:
> And here I thought you were going to fix that. Deleting the "blahs" isn't a
> fix, it's a coverup. Now there is no extended documentation at all.
I wouldn't call "Blah, blah" extended documentation -- in fact, I
would've been rath
On Tue, 19 Feb 2008 13:50:04 -0700
"Charles R Harris" <[EMAIL PROTECTED]> wrote:
> On Feb 19, 2008 12:41 PM, Stefan van der Walt
><[EMAIL PROTECTED]> wrote:
>
>> Hi Neal
>>
>> On Tue, Feb 19, 2008 at 01:38:06PM -0500, Neal Becker
>>wrote:
>> > Does numpy/scipy have a partial_sum and adj_differ
On Feb 19, 2008 12:41 PM, Stefan van der Walt <[EMAIL PROTECTED]> wrote:
> Hi Neal
>
> On Tue, Feb 19, 2008 at 01:38:06PM -0500, Neal Becker wrote:
> > Does numpy/scipy have a partial_sum and adj_difference function?
> >
> > partial_sum[i] = \sum_{j=0}^{i} x[j]
>
> numpy.cumsum
>
> Yikes, the docs
> On Feb 19, 2008 11:38 AM, Neal Becker <[EMAIL PROTECTED]> wrote:
> > adj_diff[i] = x[i] - x[i-1] : i > 1, x[i] otherwise
>
> Well, x[1:] - x[:-1] will give the usual differences. If you need the
> leading x[0] prefix the x vector with a 0.
There's also numpy.diff, and the little known numpy.edi
ti, 2008-02-19 kello 13:38 -0500, Neal Becker kirjoitti:
> Does numpy/scipy have a partial_sum and adj_difference function?
>
> partial_sum[i] = \sum_{j=0}^{i} x[j]
> adj_diff[i] = x[i] - x[i-1] : i > 1, x[i] otherwise
cumsum and diff do something like this:
>>> import numpy
>>> a = [1,2,3,4,5,3
Hi Neal
On Tue, Feb 19, 2008 at 01:38:06PM -0500, Neal Becker wrote:
> Does numpy/scipy have a partial_sum and adj_difference function?
>
> partial_sum[i] = \sum_{j=0}^{i} x[j]
numpy.cumsum
Yikes, the docstring contains "Blah, blah". I'll fix that
immediately.
> adj_diff[i] = x[i] - x[i-1] :
On Feb 19, 2008 11:38 AM, Neal Becker <[EMAIL PROTECTED]> wrote:
> Does numpy/scipy have a partial_sum and adj_difference function?
>
> partial_sum[i] = \sum_{j=0}^{i} x[j]
Make add.accumulate will do the trick:
In [1]: add.accumulate(arange(10))
Out[1]: array([ 0, 1, 3, 6, 10, 15, 21, 28, 3
-Original Message-
From: [EMAIL PROTECTED] on behalf of Francesc Altet
Instead of
for i in range(len(a)): ps[i] = a[:i].sum()
use
a.cumsum()
Nadav
Sent: Tue 19-Feb-08 20:59
To: Discussion of Numerical Python
Subject: Re: [Numpy-discussion] partial_sum/adj_difference?
A Tuesd
A Tuesday 19 February 2008, Neal Becker escrigué:
> Does numpy/scipy have a partial_sum and adj_difference function?
>
> partial_sum[i] = \sum_{j=0}^{i} x[j]
> adj_diff[i] = x[i] - x[i-1] : i > 1, x[i] otherwise
I don't know, but by using views the next should be fairly efficient:
# Partial sum
I
Does numpy/scipy have a partial_sum and adj_difference function?
partial_sum[i] = \sum_{j=0}^{i} x[j]
adj_diff[i] = x[i] - x[i-1] : i > 1, x[i] otherwise
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>
> Yes, it does, I think I tried it.
>
Strange that it worked for you, it didn't for me :|
Matthieu
--
French PhD student
Website : http://matthieu-brucher.developpez.com/
Blogs : http://matt.eifelle.com and http://blog.developpez.com/?blog=92
LinkedIn : http://www.linkedin.com/in/matthieubruch
Albert Strasheim wrote:
>
> Have you tried installing the DLLs to C:\Python2x or to the same
> directory as the numpy .pyd? As far as I know, this should work.
Yes, it does, I think I tried it. But this mean duplicating dll, and
more worrying, filesystem manipulations, which I don't like much
(w
> > It is exactly the same problem, yes. Right now, my installer does not
> > modify the environment at all (like MKL or ACML, actually), and you have
> > to do it manually (add PATH, or put in system32).
>
> Have you tried installing the DLLs to C:\Python2x or to the same
> directory as the numpy
Matthieu Brucher wrote:
>
> Yes, that works as long as there are no "real" dll that were built at
> the same time.
Well, I don't see that happening unintentionally. Installed modules have
a directory architecture, so this is not much of an issue, or am I
missing something ?
David
_
>
> > Now that you provide an installer for Atlas, it may become the same
> > problem as MKL, can't it ?
>
> It is exactly the same problem, yes. Right now, my installer does not
> modify the environment at all (like MKL or ACML, actually), and you have
> to do it manually (add PATH, or put in syst
Hello,
On Feb 19, 2008 11:34 AM, David Cournapeau <[EMAIL PROTECTED]> wrote:
> Matthieu Brucher wrote:
> >
> >
> > Now that you provide an installer for Atlas, it may become the same
> > problem as MKL, can't it ?
>
> It is exactly the same problem, yes. Right now, my installer does not
> modify t
Matthieu Brucher wrote:
>
>
> Now that you provide an installer for Atlas, it may become the same
> problem as MKL, can't it ?
It is exactly the same problem, yes. Right now, my installer does not
modify the environment at all (like MKL or ACML, actually), and you have
to do it manually (add PA
2008/2/19, David Cournapeau <[EMAIL PROTECTED]>:
>
> Matthieu Brucher wrote:
> >
> > If you use an installed ATLAS/MKL/... library, I don't know where is
> > the problem wit linking with them :|
>
>
> Atlas is not a problem, because if you know how to build a dll for
> ATLAS, you know how to handle
Matthieu Brucher wrote:
>
> If you use an installed ATLAS/MKL/... library, I don't know where is
> the problem wit linking with them :|
Atlas is not a problem, because if you know how to build a dll for
ATLAS, you know how to handle environment variable problems. It is not a
purely technical pr
Albert Strasheim wrote:
>
> Good stuff. I noticed that the Launchpad page says:
>
> "I decided not to support dynamic linking against 3rd party dll.
> Because of intrinsics windows limitations, it is impossible to do it
> in a reliable way without putting too much burden on the maintainer."
>
> I m
>
> Good stuff. I noticed that the Launchpad page says:
>
> "I decided not to support dynamic linking against 3rd party dll.
> Because of intrinsics windows limitations, it is impossible to do it
> in a reliable way without putting too much burden on the maintainer."
>
> I might note that I had pro
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