[SciPy-User] optimising python numpy snippet

[Eric Hermes]

1) Yes, that is correct. You should make sure that the relevant arrays 
(self.pooled, self.conv_out, and self.b) are NumPy arrays in order for 
the code I wrote to work properly.

Specifically, it looks like you were mostly working with self.pooled[0] 
and self.conv_out[0], so I don't really know what's going on with the 
first dimension of that array. Depending on how these are structured, 
you may need to rewrite self.pooled[0, :, :, k, l] as self.pooled[0][:, 
:, k, l], and self.conv_out[0, :, :, k*3:(k+1)*3, l*3:(l+1)*3] as 
self.conv_out[0][:, :, k*3:(k+1)*3, l*3:(l+1)*3].

2) Not really, no. NumPy/Python do not unroll loops, as this is 
typically a feature of compiled languages.
3) It should, yes.

Eric

On 7/24/2014 11:58 PM, Sai Rajeshwar wrote:
> thanks eric..  few queries
> 1)  these vector operations are possible only because of numpy,?
> 2) is the optimisation you have suugested a kind of loop unrolling..
> 3)does the above optimisation uses SIMD internally
>
> thanks
>
>
> *with regards..*
> *
> *
> *M. Sai Rajeswar*
> *M-tech  Computer Technology*
> *IIT Delhi
> ----------------------------------Cogito Ergo Sum---------
> *
>
>
> On Fri, Jul 25, 2014 at 12:07 AM, Eric Hermes <ehermes at chem.wisc.edu 
> <mailto:ehermes at chem.wisc.edu>> wrote:
>
>     Hello,
>
>     A quick and dirty simplification may end up in a bit of a speed
>     boost. You can eliminate some of the loops and replace them with
>     vector operations, as below.
>
>
>     for k in xrange(self.pooled_shape[3]):
>         for l in xrange(self.pooled_shape[4]):
>             self.pooled[0, :, :, k, l] = numpy.tanh(self.conv_out[0,
>     :, :, k*3:(k+1)*3, l*3:(l+1)*3].sum((2, 3))/9. + self.b[:, :])
>
>     I have left in some extraneous slices (:) for clarity of code.
>
>     Eric
>
>
>     On 7/24/2014 12:40 PM, Sai Rajeshwar wrote:
>>     hi all,
>>
>>       I have written the following for loop statement inn my code.. 
>>     when i profiled it.. i found that it is taking huge amount of
>>     time.. can any one suggest to make this statement faster
>>     ----------------------------------------------------------------------------
>>
>>     f*or i in xrange(self.pooled_shape[1]):
>>                 for j in xrange(self.pooled_shape[2]):
>>                     for k in xrange(self.pooled_shape[3]):
>>                         for l in xrange(self.pooled_shape[4]):
>>     self.pooled[0][i][j][k][l]=math.tanh((numpy.sum(self.conv_out[0][i][j][k*3][l*3:(l+1)*3])+numpy.sum(self.conv_out[0][i][j][k*3+1][l*3:(l+1)*3])+numpy.sum(self.conv_out[0][i][j][k*3+2][l*3:(l+1)*3]))/9.0+self.b[i][j])*
>>
>>     thanks a lot in advance
>>
>>
>>     *with regards..*
>>     *
>>     *
>>     *M. Sai Rajeswar*
>>     *M-tech  Computer Technology*
>>     *IIT Delhi
>>     ----------------------------------Cogito Ergo Sum---------
>>     *
>>
>>
>>     _______________________________________________
>>     SciPy-User mailing list
>>     SciPy-User at scipy.org  <mailto:SciPy-User at scipy.org>
>>     http://mail.scipy.org/mailman/listinfo/scipy-user
>
>     -- 
>     Eric Hermes
>     J.R. Schmidt Group
>     Chemistry Department
>     University of Wisconsin - Madison
>
>
>     _______________________________________________
>     SciPy-User mailing list
>     SciPy-User at scipy.org <mailto:SciPy-User at scipy.org>
>     http://mail.scipy.org/mailman/listinfo/scipy-user
>
>
>
>
> _______________________________________________
> SciPy-User mailing list
> SciPy-User at scipy.org
> http://mail.scipy.org/mailman/listinfo/scipy-user

-- 
Eric Hermes
J.R. Schmidt Group
Chemistry Department
University of Wisconsin - Madison

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.scipy.org/pipermail/scipy-user/attachments/20140725/bfa874d7/attachment.html>