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| From | Ian Kelly <ian.g.kelly@gmail.com> |
| Date | Thu, 20 Sep 2012 13:28:12 -0600 |
| Subject | Re: looping in array vs looping in a dic |
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On Thu, Sep 20, 2012 at 1:09 PM, MRAB <python@mrabarnett.plus.com> wrote:
> for col in range(cols):
> for row in range(rows):
> cat = valuesCategory[row, col]
> ras = valuesRaster[row, col]
> totals[cat] += ras
Expanding on what MRAB wrote, since you probably have far fewer
categories than pixels, you may be able to take better advantage of
numpy's vectorized operations (which are pretty much the whole point
of using numpy in the first place) by looping over the categories
instead:
for cat in categories:
totals[cat] += np.sum(valuesCategory * (valuesRaster == cat))
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looping in array vs looping in a dic giuseppe.amatulli@gmail.com - 2012-09-20 11:31 -0700
Re: looping in array vs looping in a dic MRAB <python@mrabarnett.plus.com> - 2012-09-20 20:09 +0100
Re: looping in array vs looping in a dic Ian Kelly <ian.g.kelly@gmail.com> - 2012-09-20 13:28 -0600
Re: looping in array vs looping in a dic Ian Kelly <ian.g.kelly@gmail.com> - 2012-09-20 13:29 -0600
Re: looping in array vs looping in a dic giuseppe.amatulli@gmail.com - 2012-09-20 16:35 -0700
Re: looping in array vs looping in a dic MRAB <python@mrabarnett.plus.com> - 2012-09-21 00:58 +0100
Re: looping in array vs looping in a dic giuseppe.amatulli@gmail.com - 2012-09-20 16:35 -0700
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