raster - Create a new GRASS database in R with CRS projection

How to create a new GRASS database in R with CRS projection? I am able to create a new one using the following code but it is not projected

require(raster)
require(spgrass6)
initGRASS("/Applications/GRASS-6.4.app/Contents/MacOS", gisDbase="/Users/junf/Documents",
          location='temp',mapset='PERMANENT', override=TRUE)
# gisdbase    /Users/junf/Documents 
# location    temp 
# mapset      PERMANENT 

# rows        1 
# columns     1 
# north       1 
# south       0 
# west        0 
# east        1 
# nsres       1 
# ewres       1 
# projection  NA 

Now I tried using a projected GeoTiff using the following code which is better but the projection is still NA:

r <- as(raster('/Users/junf/Documents/WatershedModel/UpperPulangi/upw_srtm30.tif'), 'SpatialGrid')
initGRASS("/Applications/GRASS-6.4.app/Contents/MacOS", gisDbase="/Users/junf/Documents", location='temp',mapset='PERMANENT', override=TRUE,SG=r)
# gisdbase    /Users/junf/Documents 
# location    temp 
# mapset      PERMANENT 
# rows        3317 
# columns     2774 
# north       950826 
# south       849428.7 

# west        690839.6 
# east        775638 
# nsres       30.56898 
# ewres       30.569 
# projection  NA 

Can someone please help me create a new GRASS database with WGS 84 (EPSG: 4326) projection or a projection that matches an existing georeferenced image for import in GRASS?

Answer

I came up with the following approach which is adopted from R-sig-Geo. First, create a new location via initGRASS using the default PERMANENT mapset. Next, set the desired coordinate reference system (CRS). And finally, create a new mapset which will automatically inherit the CRS from PERMANENT.

library(rgrass7)


## initialize new location and baseline mapset with required epsg code
gisBase <- system("grass72 --config path", intern = TRUE)

initGRASS(gisBase = gisBase, home = raster::tmpDir(), 
          gisDbase = "~/grassdata", location = "tmp", 
          mapset = "PERMANENT", override = TRUE)

execGRASS("g.proj", flags = "c", epsg = 4326)


## initialize new mapset inheriting projection info
execGRASS("g.mapset", flags = "c", mapset = "new_mapset")

Ideally, you should call g.mapset and g.region with print option enabled afterwards to check if everything is running smoothly.

execGRASS("g.mapset", flags = "p")
# new_mapset

execGRASS("g.region", flags = "p")
# projection: 3 (Latitude-Longitude)
# zone:       0

# datum:      wgs84
# ellipsoid:  wgs84
# north:      1N
# south:      0
# west:       0
# east:       1E
# nsres:      1
# ewres:      1
# rows:       1
# cols:       1

# cells:      1