[R-sig-Geo] rbind and spRbind

[Danlin Yu]

Agustin:

Since you are using the sp method for binding, I suppose the coordinates 
(in UTM project according to the name) are added automatically (as the 
added two new names are UTMX and UTMY). Why not check these two values 
to see what's in them.

Hope this helps.

Danlin


Agustin Lobo wrote:
> I'm a bit confused with the following:
>
> I have a SPDF object ika1v4
>
> > dim(ika1v4geo at data)
> [1] 693  23
> > dim(ika1v4geo)
> [1] 693  23
>
> Then I do an rbind:
>
> > a <- rbind(ika1v4geo,ika1v4geo)
> > dim(a)
> [1] 1386   23
> > dim(a at data)
> [1] 1386   23
>
> But spRbind introduces 2 variables:
> > a2 <- spRbind(ika1v4geo,ika1v4geo)
> > dim(a2)
> [1] 1386   25
> > dim(a2 at data)
> [1] 1386   25
>
> > names(a at data)
>  [1] "IKAPUNTO" "IKAID"    "CN"       "dia"      "hora_obs" "GPSID"
>  [7] "GPS"      "N_PUNTO"  "GUIA"     "MONITOR"  "COD_SP_C" "SP_C"
> [13] "COD_OBS"  "OBS"      "N"        "VULN"     "VULNT"    "CL"
> [19] "A"        "H"        "D"        "S"        "V"
> > names(a2 at data)
>  [1] "IKAPUNTO" "IKAID"    "CN"       "dia"      "hora_obs" "GPSID"
>  [7] "GPS"      "UTMX"     "UTMY"     "N_PUNTO"  "GUIA"     "MONITOR"
> [13] "COD_SP_C" "SP_C"     "COD_OBS"  "OBS"      "N"        "VULN"
> [19] "VULNT"    "CL"       "A"        "H"        "D"        "S"
> [25] "V"
> >
>
> Why? Which are the differences between rbind and spRbind?
>
> Thanks!
>
> Agus

-- 
___________________________________________
Danlin Yu, Ph.D.
Assistant Professor
Department of Earth & Environmental Studies
Montclair State University
Montclair, NJ, 07043
Tel: 973-655-4313
Fax: 973-655-4072
email: yud at mail.montclair.edu
webpage: csam.montclair.edu/~yu