R help - Feb 2018 - Concatening two maps/shapefiles...

Dear All,
I'm new with mapping and using shapefiles in R.

I use the version: R 3.2.1 GUI 1.66 with Snow Leopard Mac OS (6956)

I want to build a map of the countries of Africa, in order to add points of
collecting species of beetles, for later publishing.

library(maptools)
library(mapdata)

When I put the extreme coordinates of Africa, the map began only at longitude 0?
and thus lacks the west africa part:

x<-map('world2Hires', xlim=c(-18,52), ylim=c(-35,38))

I attempted with the following script:


E<-map('world2Hires', xlim=c(0,52), ylim=c(-35,38))
W<-map('world2Hires', xlim=c(342,360), ylim=c(-35,38))

It ran fine but now I don't know how to get these two maps jointed.
I guess it may be trivial but I didn't found nothing about this in the
available tutorials.
Cheers,
Nicolas Degallier



Nicolas Degallier
120 rue de Charonne
F-75011 Paris

nicolas.degallier at free.fr
Publications :
http://www.documentation.ird.fr/hor/DEGALLIER,NICOLAS/tout

I would try using the xlim, ylim arguments in your first map() command, and then
using the add argument in the second one. See the help page for the map
function.

This assumes that the map() function you are using comes from the maps package.

Otherwise, perhaps you should be using the rgdal package to load your shapefiles
into R (you did mention shapefiles), and the basic plot() command to plot them.
Depending on whether you choose to use the 'sp' package or the
'sf' package.

See also the R-sig-geo mailing list.

-Don

--
Don MacQueen
Lawrence Livermore National Laboratory
7000 East Ave., L-627
Livermore, CA 94550
925-423-1062
Lab cell 925-724-7509
 
 
?On 2/5/18, 10:40 AM, "R-help on behalf of Nicolas Degallier"
<r-help-bounces at r-project.org on behalf of nicolas.degallier at
free.fr> wrote:

    Dear All,
    I'm new with mapping and using shapefiles in R.
    
    I use the version: R 3.2.1 GUI 1.66 with Snow Leopard Mac OS (6956)
    
    I want to build a map of the countries of Africa, in order to add points of
collecting species of beetles, for later publishing.
    
    library(maptools)
    library(mapdata)
    
    When I put the extreme coordinates of Africa, the map began only at
longitude 0? and thus lacks the west africa part:
    
    x<-map('world2Hires', xlim=c(-18,52), ylim=c(-35,38))
    
    I attempted with the following script:
    
    
    E<-map('world2Hires', xlim=c(0,52), ylim=c(-35,38))
    W<-map('world2Hires', xlim=c(342,360), ylim=c(-35,38))
    
    It ran fine but now I don't know how to get these two maps jointed.
    I guess it may be trivial but I didn't found nothing about this in the
available tutorials.
    Cheers,
    Nicolas Degallier
    
    
    
    Nicolas Degallier
    120 rue de Charonne
    F-75011 Paris
    
    nicolas.degallier at free.fr
    Publications :
    http://www.documentation.ird.fr/hor/DEGALLIER,NICOLAS/tout
    
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