[Gstat-info] Re: two rapid questions: change column name in a slot and overlay(SpatialPixels, SpatialPoints)

[G. Allegri]

Solved the second questions. I didn't understood that overlay returns
the x index values at y locations...
The first remains.

2008/3/12, G. Allegri <giohappy at gmail.com>:
> I've also tried:
>
>  overlay(EceZKRIG0_3[,"V151"],t0)
>
>  but it doesn't help
>
>  2008/3/12, G. Allegri <giohappy at gmail.com>:
>
> > I've two questions more (I will stop soon!):
>  >
>  >  1 - I'm trying to change a column name of the data slot of a
>  >  SpatialPixelsDataFrame
>  >  I've added the column this way:
>  >  slot(EceZKRIG0_3,"data")[,index]<-Sim_mean_approx[[2]]
>  >
>  >  The column added is V151 (as 151 is the actual index).
>  >  I want to rename it, and I've tried:
>  >
>  >  names(slot(EceZKRIG0_3,"data")[index])<-"Mean_approx"
>  >
>  >  No errors are raised, but the column remain V151. What's wrong?
>  >
>  >  2 - I need to extract the values from a SpatialPixelsDataFrame (SP1)
>  >  at SpatialPointsDataFrame (SP2) locations.
>  >  I've simply used:
>  >
>  >  overlay(EceZKRIG0_3,t0)
>  >
>  >  where EceZKRIG0_3 is SP1 and t0 is SP2. It returns some numerical
>  >  values that I don't know what they refer to. How can I indicate that I
>  >  want to extract a certain data column from SP1 (V151, in this case)?
>  >
>  >  Thanks very much, as usual.
>  >  Giovanni
>  >
>