intro

OSMscale is an R package to easily handle and project lat-long coordinates, download background maps and add a correct scale bar to 'OpenStreetMap' plots in any map projection. There are some other spatially related miscellaneous functions as well.

installation

OSMscale is available on CRAN:

It relies on OpenStreetMap to do the actual work, thus rgdal and rjava must be available.

• On Windows: Check if Java is available. There should be no errors when running install.packages("rJava") ; library(rJava) in R. If necessary, install Java in the same bit-version as R (eg 64bit). The Java binary file must be on the search path, which will normally happen automatically.

• On Linux: open a terminal (CTRL+ALT+T) and paste (CTRL+SHIFT+V) the following line by line to install gdal and rJava:

sudo apt update
sudo apt install libgdal-dev libproj-dev
sudo apt-get install r-cran-rjava
R
install.packages("rgdal")
library("rgdal"); library("rJava") # should not return errors
q("no") # to quit R

• Now actually install OSMscale from within R:

install.packages("OSMscale") 
library(OSMscale)
?OSMscale

# To update to the most recent development version:
if(!requireNamespace("remotes", quitly=TRUE)) install.packages("remotes")
remotes::install_github("brry/OSMscale")

In case you run into the 32/64 bits error: "JAVA_HOME cannot be determined from the Registry", try
remotes::install_github("brry/OSMscale", build_opts="--no-multiarch")

basic usage

Assuming a data.frame with lat-long coordinates:

d <- read.table(sep=",", header=TRUE, text=
"lat, long # could e.g. be copied from googleMaps, rightclick on What's here?
55.685143, 12.580008
52.514464, 13.350137
50.106452, 14.419989
48.847003, 2.337213
51.505364, -0.164752")
png("ExampleMap.png", width=4, height=3, units="in", res=150)

map <- pointsMap(lat, long, data=d, type="maptoolkit-topo", proj=putm(d$long), scale=FALSE)
scaleBar(map, abslen=500, y=0.8, cex=0.8)
lines(projectPoints(d$lat, d$long), col="blue", lwd=3)
points(projectPoints(52.386609, 4.877008, to=putm(zone=32)), cex=3, lwd=2, col="purple")

dev.off()

trouble

If direct installation doesn't work, your R version might be too old. In that case, an update is really recommendable: r-project.org. If you can't update R, try installing from source (github) via instGit as mentioned above. If that's not possible either, you might be able to source some functions from the package zip folder

Vectorize(source)(dir("path/you/unzipped/to/OSMscale-master/R", full=T))

This creates all R functions as objects in your globalenv workspace (and overwrites existing objects of the same name!).