Re: [Scikit-learn-general] Computation of Gini Index in Decision Tree

2012-01-16 Thread Andreas
On 01/16/2012 10:12 AM, Andreas wrote: > On 01/16/2012 10:07 AM, Andreas wrote: > >> On 01/16/2012 09:44 AM, Andreas wrote: >> >> >>> Hi Everybody. >>> I'm still trying to hack at the trees. This time I stumbled across the >>> computation of the Gini index. >>> Could someone please explai

Re: [Scikit-learn-general] Computation of Gini Index in Decision Tree

2012-01-16 Thread Gael Varoquaux
On Mon, Jan 16, 2012 at 10:13:44AM +0100, Andreas wrote: > I'm not sure I used the right proposition, though. > Hacking at the trees probably means hacking in the woods. > I guess I should just be hacking the trees, which > makes more sense in either context. Actually no, if you look up the litera

Re: [Scikit-learn-general] Computation of Gini Index in Decision Tree

2012-01-16 Thread Andreas
On 01/16/2012 10:06 AM, Olivier Grisel wrote: > 2012/1/16 Andreas: > >> Hi Everybody. >> I'm still trying to hack at the trees. >> > Which is an etymologically valid attitude. > >http://etymonline.com/?search=hack > > As for your question, I let the tree experts answer :) > > I'm

Re: [Scikit-learn-general] Computation of Gini Index in Decision Tree

2012-01-16 Thread Andreas
On 01/16/2012 10:07 AM, Andreas wrote: > On 01/16/2012 09:44 AM, Andreas wrote: > >> Hi Everybody. >> I'm still trying to hack at the trees. This time I stumbled across the >> computation of the Gini index. >> Could someone please explain this to me? >> Hastie, Tishirani and Friedman told me th

Re: [Scikit-learn-general] Computation of Gini Index in Decision Tree

2012-01-16 Thread Gael Varoquaux
On Mon, Jan 16, 2012 at 10:06:18AM +0100, Olivier Grisel wrote: > 2012/1/16 Andreas : > > I'm still trying to hack at the trees. > Which is an etymologically valid attitude. > http://etymonline.com/?search=hack As long as you are not doing it with a tray ( http://www.youtube.com/watch?v=Sv5iEK

Re: [Scikit-learn-general] Computation of Gini Index in Decision Tree

2012-01-16 Thread Olivier Grisel
2012/1/16 Andreas : > Hi Everybody. > I'm still trying to hack at the trees. Which is an etymologically valid attitude. http://etymonline.com/?search=hack As for your question, I let the tree experts answer :) -- Olivier http://twitter.com/ogrisel - http://github.com/ogrisel ---

Re: [Scikit-learn-general] Computation of Gini Index in Decision Tree

2012-01-16 Thread Andreas
On 01/16/2012 09:44 AM, Andreas wrote: > Hi Everybody. > I'm still trying to hack at the trees. This time I stumbled across the > computation of the Gini index. > Could someone please explain this to me? > Hastie, Tishirani and Friedman told me this is computed as > \sum_{k} p_{mk}*(1- p_{mk}) > wh

[Scikit-learn-general] Computation of Gini Index in Decision Tree

2012-01-16 Thread Andreas
Hi Everybody. I'm still trying to hack at the trees. This time I stumbled across the computation of the Gini index. Could someone please explain this to me? Hastie, Tishirani and Friedman told me this is computed as \sum_{k} p_{mk}*(1- p_{mk}) where k enumerates the classes and m denotes a node (I