[R] Subseting in a 3D array

[Agustin Lobo]

Hi!

I have a 3d array:
> dim(ib5km15.dbc)
[1] 190 241  19

and a set of positions to extract:
> ib5km.lincol.random[1:3,]
     [,1] [,2]
[1,]   78   70
[2,]   29  213
[3,]  180   22

Geting the values of a 2D array
for that set of positions would
be:

> ima <- ib5km15.dbc[,,1]
> ima[ib5km.lincol.random[1:10,]]

but don't find the way for the case
of the 3D array:

> ib5km15.dbc[ib5km.lincol.random[1:10,],]
Error in ib5km15.dbc[ib5km.lincol.random[1:10, ], ] :
        incorrect number of dimensions

Could anyone suggest the way of subseting
the 3D array to get a vector of z values
for each position recorded in ib5km.lincol.random?
(avoiding the use of for loops).

Thanks

Agus

Dr. Agustin Lobo
Instituto de Ciencias de la Tierra (CSIC)
Lluis Sole Sabaris s/n
08028 Barcelona SPAIN
tel 34 93409 5410
fax 34 93411 0012
alobo at ija.csic.es