Re: [R] logistic regression tree

2010-08-22 Thread Peter Dalgaard
On 08/22/2010 01:51 PM, Kay Cichini wrote: > achim, thank you for the very kind offer!! sorrily i'm not around vienna in > the near feature, otherwise i'd be glad to coming back to your invitation. Not that it's any of my business, but I don't think you need to go THAT far to visit Achim these da

Re: [R] logistic regression tree

2010-08-22 Thread Kay Cichini
dear all, thank you everyone for the profound answers and the needful references! achim, thank you for the very kind offer!! sorrily i'm not around vienna in the near feature, otherwise i'd be glad to coming back to your invitation. yours, kay - Kay Cichini Postgrad

Re: [R] logistic regression tree

2010-08-20 Thread Frank Harrell
On Fri, 20 Aug 2010, Kay Cichini wrote: hello, my data-collection is not yet finished, but i though have started investigating possible analysis methods. below i give a very close simulation of my future data-set, however there might be more nominal explanatory variables - there will be no

Re: [R] logistic regression tree

2010-08-20 Thread Gavin Simpson
On Fri, 2010-08-20 at 14:46 -0700, Kay Cichini wrote: > hello, > > my data-collection is not yet finished, but i though have started > investigating possible analysis methods. > > below i give a very close simulation of my future data-set, however there > might be more nominal explanatory variabl

Re: [R] logistic regression tree

2010-08-20 Thread Kay Cichini
hello, my data-collection is not yet finished, but i though have started investigating possible analysis methods. below i give a very close simulation of my future data-set, however there might be more nominal explanatory variables - there will be no continous at all (maybe some ordered nominal

Re: [R] logistic regression tree

2010-08-20 Thread Frank Harrell
It would be good to tell us of the frequency of observations in each category of Y, and the number of continuous X's. Recursive partitioning will require perhaps 50,000 observations in the less frequent Y category for its structure and predicted values to validate, depending on X and the sig

Re: [R] logistic regression tree

2010-08-20 Thread Achim Zeileis
On Fri, 20 Aug 2010, Kay Cichini wrote: hello gavin & achim, thanks for responding. by logistic regression tree i meant a regression tree for a binary response variable. but as you say i could also use a classification tree - in my case with only two outcomes. i'm not aware if there are s

Re: [R] logistic regression tree

2010-08-20 Thread Kay Cichini
hello gavin & achim, thanks for responding. by logistic regression tree i meant a regression tree for a binary response variable. but as you say i could also use a classification tree - in my case with only two outcomes. i'm not aware if there are substantial differences to expect for the two a

Re: [R] logistic regression tree

2010-08-19 Thread Achim Zeileis
On Thu, 19 Aug 2010, Gavin Simpson wrote: On Thu, 2010-08-19 at 13:42 -0700, Kay Cichini wrote: hello everyone, i sampled 100 stands at 20 restoration sites and presence of 3 different invasive plant species. i came across logistic regression trees and wonder if this is suited for my purpose -

Re: [R] logistic regression tree

2010-08-19 Thread Gavin Simpson
On Thu, 2010-08-19 at 13:42 -0700, Kay Cichini wrote: > hello everyone, > > i sampled 100 stands at 20 restoration sites and presence of 3 different > invasive plant species. > i came across logistic regression trees and wonder if this is suited for my > purpose - predicting presence of these pro

[R] logistic regression tree

2010-08-19 Thread Kay Cichini
hello everyone, i sampled 100 stands at 20 restoration sites and presence of 3 different invasive plant species. i came across logistic regression trees and wonder if this is suited for my purpose - predicting presence of these problematic invasive plant species (one by one) by a set of recorded