[R] rpart with circular data?

Hi I am planning to use a CART analysis with rpart() to analyse the impact of, among others, slope, altitude and aspect on mortality rates. My question is: Is there a p[roblem with using aspect as a predictor as it is circular? And if it is a problem (which I suspect), is there a transformation I

Re: [R] rpart with circular data?

Hi Rainer, In a similar situation I used the two components of the normal vector of the surface (northing easting). I.e. for a horizontal plane both are 0, for a vertical slope facing south northing=-1and easting=0, etc. This descartian decomposition of the slope vector avoids the problem of

Re: [R] rpart with circular data?

On Mon, May 12, 2008 at 6:29 AM, Bálint Czúcz [EMAIL PROTECTED] wrote: Hi Rainer, In a similar situation I used the two components of the normal vector of the surface (northing easting). I.e. for a horizontal plane both are 0, for a vertical slope facing south northing=-1and easting=0, etc.