[R-sig-Geo] putting scalebar and north arrow on google map

[Bacou, Melanie]

No self promotion, but in case you're looking for code examples using 
leaflet plugins (scalebar and minimap) available through `tmap` :
http://tools.harvestchoice.org/ar/ (code is linked at the bottom of the 
page).

--Mel.


On 7/18/2016 8:36 AM, Tim Appelhans wrote:
> My suggestion would be the wonderful tmap package. It is, however, 
> using OpenStreetMap rather than google for background maps AFAIK.
>
> Tim
>
> On 18.07.2016 14:32, Manuel Spínola wrote:
>> Or you can try the package ggsn with the package ggmap
>>
>> Manuel
>>
>> 2016-07-17 22:57 GMT-06:00 Chris Lusk <clusk at waikato.ac.nz>:
>>
>>> Hi - I've made a map to show the spatial arrangement of my plots, 
>>> and would
>>> now like to add a scale bar (in hundreds of metres) and a north 
>>> arrow. I've
>>> seen several solutions online, most of which threw error messages 
>>> when I
>>> tried them. Although the solution below doesn't give an error 
>>> message, it
>>> doesn't actually add anything to the map!
>>>
>>> Any advice would be appreciated.
>>>
>>> Chris
>>> ..........
>>>
>>> library(ggplot2)
>>> library(ggmap)
>>> library(maps)
>>> library(GISTools)
>>>
>>> ##Coordinates of four types of plots
>>> Gaps <- read.table(text="lon lat
>>> 176.431823     -38.086894
>>> 176.4329002     -38.08855667
>>> 176.4286505     -38.08421246
>>> 176.4239767     -38.08297953
>>> 176.4306576     -38.09032491
>>> 176.4181457     -38.08283416
>>> 176.4325089     -38.09042394
>>> 176.4243027     -38.08215021
>>> 176.4220882     -38.08720573
>>> 176.430974    -38.093108", header = TRUE, strip.white = TRUE)
>>>
>>> Understorey <- read.table(text="lon lat
>>> 176.431523   -38.086965
>>> 176.418408   -38.082935
>>> 176.4244189     -38.08242069
>>> 176.4287644     -38.08372266
>>> 176.4240118     -38.0823004
>>> 176.4333778     -38.08853369
>>> 176.4217424     -38.0876122
>>> 176.4309304     -38.09055117
>>> 176.4324084     -38.0907023
>>> 176.430821   -38.093687", header = TRUE, strip.white = TRUE)
>>>
>>> Treeferns <- read.table(text="lon lat
>>> 176.432134      -38.086298
>>> 176.4246547     -38.08226916
>>> 176.4335132     -38.08801622
>>> 176.4183628     -38.08260261
>>> 176.429       -38.08413018
>>> 176.4213997     -38.08710868
>>> 176.4304333     -38.09064678
>>> 176.4324081     -38.0909994
>>> 176.4242689     -38.08264669
>>> 176.429837      -38.093061", header = TRUE, strip.white = TRUE)
>>>
>>> Margins <- read.table(text="lon lat
>>> 176.4225302     -38.08177849
>>> 176.427018     -38.08879161
>>> 176.4207786     -38.08356826
>>> 176.4315118     -38.08251629
>>> 176.426456     -38.08920441
>>> 176.426010   -38.088253
>>> 176.422526   -38.082794
>>> 176.421399   -38.084780
>>> 176.429339   -38.092742", header = TRUE, strip.white = TRUE)
>>>
>>> ## Get the map at right zoom level
>>> OkatainaMap <- get_googlemap(center = c(lon = 176.425, lat = -38.0845),
>>> maptype='hybrid', zoom=15)
>>>
>>> ## Plot the points on the map
>>> ggmap(OkatainaMap) +
>>>    geom_point(data=Gaps, aes(x=lon, y=lat), pch=15, 
>>> colour="chartreuse1",
>>> size=2.5, alpha=1) +
>>>    geom_point(data=Understorey, aes(x=lon, y=lat), pch=21, 
>>> colour="gray40",
>>> bg="black", size=3, alpha=1) +
>>>    geom_point(data=Treeferns, aes(x=lon, y=lat), pch=23, 
>>> colour="gray40",
>>> bg="blue", size=2.5, alpha=1) +
>>>    geom_point(data=Margins, aes(x=lon, y=lat), pch=17, colour="orange",
>>> size=2.5, alpha=1)
>>>
>>> ##Add scale and north arrow (NEITHER COMMAND WORKS FOR ME)
>>>
>>> map.scale(x=176.42,y=-38.092, ratio=FALSE, relwidth=0.2, col="white")
>>> north.arrow(xb=176.435, yb=-38.079, len=0.02, lab="N", col="white")
>>>
>>> ...................
>>>
>>>
>>> Dr. Chris Lusk
>>> Senior Research Fellow
>>> Environmental Research Institute
>>> The University of Waikato
>>> Private Bag 3105, Hamilton
>>> New Zealand / Aotearoa
>>> http://sci.waikato.ac.nz/sites/clusk/
>>> Ph 64 7 838 4205
>>> Senior Editor, *NZ J Botany*
>>> ~  ~  ~  ~  ~  ~  ~  ~  ~  ~  ~
>>>
>>>          [[alternative HTML version deleted]]
>>>
>>> _______________________________________________
>>> R-sig-Geo mailing list
>>> R-sig-Geo at r-project.org
>>> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>>>
>>
>>
>