change a column name of the data slot

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?

Giovanni

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"
The point of the Spatial*DataFrame classes is to look like GIS to GIS 
people and data.frames to data people. Isn't it easier just to say:

EceZKRIG0_3$Mean_approx <- Sim_mean_approx[[2]]

There is also a names()<- method, so if you wanted to change a name, you 
could do it:

names(EceZKRIG0_3)[151] <- "Mean_approx"

library(sp)
data(meuse)
coordinates(meuse) <- c("x", "y")
class(meuse)
names(meuse)
meuse$s_lime <- sample(meuse$lime)
names(meuse)
names(meuse)[13] <- "not_slime"
names(meuse)

OK? Isn't that easier?

Roger
No errors are raised, but the column remain V151. What's wrong?

Giovanni

_______________________________________________
R-sig-Geo mailing list
R-sig-Geo at stat.math.ethz.ch
https://stat.ethz.ch/mailman/listinfo/r-sig-geo

Roger Bivand
Economic Geography Section, Department of Economics, Norwegian School of
Economics and Business Administration, Helleveien 30, N-5045 Bergen,
Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43
e-mail: Roger.Bivand at nhh.no
Roger, I have to get experience yet... I thought that the right way to
access the datas in Spatial*DataFrame should be through the use of
slots.
Thanks for the hint. Now things get easier! :-)

2008/3/12, Roger Bivand <Roger.Bivand at nhh.no>:
On Wed, 12 Mar 2008, G. Allegri wrote:

 > 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"

The point of the Spatial*DataFrame classes is to look like GIS to GIS
 people and data.frames to data people. Isn't it easier just to say:

 EceZKRIG0_3$Mean_approx <- Sim_mean_approx[[2]]

 There is also a names()<- method, so if you wanted to change a name, you
 could do it:

 names(EceZKRIG0_3)[151] <- "Mean_approx"

 library(sp)
 data(meuse)
 coordinates(meuse) <- c("x", "y")
 class(meuse)
 names(meuse)
 meuse$s_lime <- sample(meuse$lime)
 names(meuse)
 names(meuse)[13] <- "not_slime"
 names(meuse)

 OK? Isn't that easier?

 Roger

 >
 > No errors are raised, but the column remain V151. What's wrong?
 >
 > Giovanni
 >

_______________________________________________
 > R-sig-Geo mailing list
 > R-sig-Geo at stat.math.ethz.ch
 > https://stat.ethz.ch/mailman/listinfo/r-sig-geo
 >

 --
 Roger Bivand
 Economic Geography Section, Department of Economics, Norwegian School of
 Economics and Business Administration, Helleveien 30, N-5045 Bergen,
 Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43
 e-mail: Roger.Bivand at nhh.no