[Qgis-developer] adding graduated symbol classification algorithms

[Tim Sutton]

Hi Carson

On Fri, Sep 24, 2010 at 11:33 PM, Carson Farmer <carson.farmer at gmail.com> wrote:
> Hi Devs, attached is a diff that adds 3 new modes to the graduated
> symbol renderer, including Jenks' Natural Breaks Optimisation
> algorithm, a standard deviation classification algorithm, and the
> 'pretty' algorithm from the R statistical programming language. An
> explanation of the algorithms is provided as comments in-code, and you
> can also have a look here: http://www.carsonfarmer.com/?p=761 for the
> initial Python version, along with a brief overview of the algorithms
> etc. I'd really appreciate any comments, suggestions, or fixes, as I'm
> not really a C++ programmer. I'm sure there are a few spots where
> things could be sped up, especially in the Jenks algorithm. Right now
> I'm using a random sample to speed things up, but I'm sure others more
> familiar with C++ could find other speed improvements. I don't really
> want to commit this directly, again mainly because I'm not really
> confident in my C++ abilities, but if it would make it easier, I can
> also add the patch as an enhancement ticket?
>

I really like the new functionality your patch adds - I even wrote a
little blog post about it :-) [1] The code works fine my only comment
regarding the c++ implementation is that it doesn't follow our coding
style guidelines. See the CODING document in the root of your source
tree for details. e.g variable names should be camelCased, and so on.
If you resolve those, issues I would be most happy to see your work
added to trunk.

Regards

Tim




[1] http://linfiniti.com/2010/09/new-class-breaks-for-graduated-symbols-in-qgis/


> Thanks,
>
> Carson
>
> --
> Carson J. Q. Farmer
> ISSP Doctoral Fellow
> National Centre for Geocomputation
> National University of Ireland, Maynooth,
> http://www.carsonfarmer.com/
>
> _______________________________________________
> Qgis-developer mailing list
> Qgis-developer at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/qgis-developer
>
>



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Tim Sutton - QGIS Project Steering Committee Member (Release  Manager)
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