>> idx=N.ravel(x)!=0
>> A[:,idx]*x[idx]
On Fri, 14 Dec 2007, dmitrey apparently wrote:
> I expect being vector of length n A and x change
> every iter. A is not sparse.
Still, whenever x has a lot of zeros,
this should have a substantial payoff.
That seems the only exploitable information
yo
On Dec 14, 2007, at 14:33 , Christopher Barker wrote:
> HI all,
>
> Someone on the wxPython list just pointed out that the math module now
> includes includes angle-conversion utilities:
>
degrees.__doc__
> degrees(x) -> converts angle x from radians to degrees
radians.__doc__
> radians(
Thank you for the tip, however, I expect being vector of length n
A and x change every iter. A is not sparse.
Alan G Isaac wrote:
> On Fri, 14 Dec 2007, dmitrey apparently wrote:
>
>> I guess it doesn't matter, but typical n are 1...1000.
>> However, I need to call the operation hundreds or t
HI all,
Someone on the wxPython list just pointed out that the math module now
includes includes angle-conversion utilities:
>>> degrees.__doc__
degrees(x) -> converts angle x from radians to degrees
>>> radians.__doc__
radians(x) -> converts angle x from degrees to radians
Not a big deal, bu
Let me announce SFE-00.35.01, bringing per term integration - now each
term can use its own quadrature points. This is a major change at the
heart of the code - some parts may not work as all terms were not
migrated yet to the new framework. All test examples work, though, as
well as acoustic b
Hi,
How sparse are A, x and Ax?
You probably will not find any time or operation efficiency unless A
and x are relatively sparse. With the small size of n, any efficiency
will typically be small in any case.
As you indicate that this has to be repeated multiple times, perhaps
you should look at y
Hi Sebastian
N.fromiter only works on 1D arrays. I thought the following may work,
but it doesn't:
np.fromiter(np.ndindex(10,10,10),N.dtype((int,3)))
This kind of loop is probably best implemented in C, although I think
Jonathan's version is rather clever.
Regards
Stéfan
On Fri, Dec 14, 2007
On Fri, 14 Dec 2007, dmitrey apparently wrote:
> I guess it doesn't matter, but typical n are 1...1000.
> However, I need to call the operation hundreds or thousands times (while
> running NLP solver ralg, so 4..5 * nIter times).
> Number of zeros can be 0...n-1
Do both A and x change every it
I guess it doesn't matter, but typical n are 1...1000.
However, I need to call the operation hundreds or thousands times (while
running NLP solver ralg, so 4..5 * nIter times).
Number of zeros can be 0...n-1
Charles R Harris wrote:
> How big is n?
>
> On Dec 14, 2007 1:24 AM, dmitrey <[EMAIL PROT
How big is n?
On Dec 14, 2007 1:24 AM, dmitrey <[EMAIL PROTECTED]> wrote:
> Hi all,
> I have to get Ax, A is n x n matrix, x is vector of length n.
> Some coords of x are zeros, so I want to economy time/cputime somehow
> w/o connecting sparse module from scipy.
> What's the easiest way to do so
Do you know about
N.fromiter()
?
-Sebastian Haase
On Dec 14, 2007 12:33 AM, Jonathan Taylor <[EMAIL PROTECTED]> wrote:
> I was needing an array representation of ndindex since ndindex only
> gives an iterator but array(list(ndindex)) takes too long. There is
> prob some obvious way to do this I
Hi all,
I have to get Ax, A is n x n matrix, x is vector of length n.
Some coords of x are zeros, so I want to economy time/cputime somehow
w/o connecting sparse module from scipy.
What's the easiest way to do so?
Thx, D.
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