[Numpy-discussion] downsample vector with averaging

[Ryan Krauss]

Thanks Scott and Tim. These look good, and very similar.

On 5/8/06, Scott Ransom <sransom at nrao.edu> wrote:
> How about this:
>
> ---------------------------------------------
> import numpy as Num
>
> def downsample(vector, factor):
>     """
>     downsample(vector, factor):
>         Downsample (by averaging) a vector by an integer factor.
>     """
>     if (len(vector) % factor):
>         print "Length of 'vector' is not divisible by 'factor'=%d!" % factor
>         return 0
>     vector.shape = (len(vector)/factor, factor)
>     return Num.mean(vector, axis=1)
> ---------------------------------------------
>
> Scott
>
>
> On Mon, May 08, 2006 at 01:17:16PM -0400, Ryan Krauss wrote:
> > I need to downsample some data while averaging it.  Basically, I have
> > a vector and I want to take for example every ten points and average
> > them together so that the new vector would be made up of
> > newvect[0]=oldvect[0:9].mean()
> > newvect[1]=oldevect[10:19].mean()
> > ....
> >
> > Is there a built-in or vectorized way to do this?  I default to
> > thinking in for loops, but that can lead to slow code.
> >
> > Thanks,
> >
> > Ryan
> >
> >
> > -------------------------------------------------------
> > Using Tomcat but need to do more? Need to support web services, security?
> > Get stuff done quickly with pre-integrated technology to make your job
> > easier
> > Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo
> > http://sel.as-us.falkag.net/sel?cmd_______________________________________________
> > Numpy-discussion mailing list
> > Numpy-discussion at lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/numpy-discussion
>
> --
> --
> Scott M. Ransom            Address:  NRAO
> Phone:  (434) 296-0320               520 Edgemont Rd.
> email:  sransom at nrao.edu             Charlottesville, VA 22903 USA
> GPG Fingerprint: 06A9 9553 78BE 16DB 407B  FFCA 9BFA B6FF FFD3 2989
>