ggsn only supports one variable faceting. At the moment, when using two variables the scale bar is drawn on multiple facets. For example:

library(rgdal); library(broom); library(dplyr);
dsn <- system.file('extdata', package = 'ggsn')

## Map in geographic coordinates.
map <- readOGR(dsn, 'sp')
map@data$id <- 1:nrow(map@data)
map.df <- merge(tidy(map), map, by = 'id')

map_df <- bind_rows(
    map.df %>% mutate(f1 = "a", f2 = "c"),
    map.df %>% mutate(f1 = "b", f2 = "c"),
    map.df %>% mutate(f1 = "a", f2 = "d"),
    map.df %>% mutate(f1 = "b", f2 = "d")
)

ggplot(data = map_df, aes(long, lat, group = group, fill = nots)) +
    geom_polygon() +
    coord_equal() +
    geom_path() +
    facet_grid(f1~f2) +
    scale_fill_brewer(name = 'Animal abuse\nnotifications', palette = 8) +
    scalebar(map.df, dist = 5, dd2km = TRUE, model = 'WGS84', facet.var = 'f1', facet.lev = 'a')

Two variable faceting could be specified by supplying a vector of variable names and facet levels.

ggplot(data = map_df, aes(long, lat, group = group, fill = nots)) +
    geom_polygon() +
    coord_equal() +
    geom_path() +
    facet_grid(f1~f2) +
    scale_fill_brewer(name = 'Animal abuse\nnotifications', palette = 8) +
    scalebar(map.df, dist = 5, dd2km = TRUE, model = 'WGS84', facet.var = c('f1', 'f2'), facet.lev = c('a', 'b'))

Dear Oswaldo,

just found out about your package. It's very useful, but it could use some more flexibility in my opinion. Have you thought about letting the user modify the scalebar border and fill colors? This would make it more adequate for use on top of e.g. darker satellite images obtained through ggmap (I did run into this you see ...). If you think it is a good idea, I'd be happy to contribute.

Kind regards,
Bart

PS The workaround I use now is adding a transparent white rectangle below the scalebar.

Hi there! i'm noticing some unusual behaviour with the scalebar function and wondered if you had seen this before.

My code is here

# plot ggplot
ggplot() +
  geom_polygon(data = study_area_df, aes(x = long, y = lat, group = group),
               fill = "white", color = "black") +
  geom_path(data = sjer_roads_df, aes(x = long, y = lat,
                                      group = group, size = factor(RTTYP)), colour = "grey") +
  scale_size_manual("Road Type", values = c("M" = .3,
                                            "S" = .8,
                                            "Unknown" = .3)) +
  geom_point(data = sjer_plots_df, aes(x = coords.x1,
                                       y = coords.x2, shape = factor(plot_type), color = factor(plot_type)), size = 3) +
  scale_color_manual("Plot Type", values = c("trees" = "darkgreen",
                                 "grass" = "darkgreen",
                                 "soil" = "brown")) +
  scale_shape_manual("Plot Type", values = c("grass" = 18,
                                             "soil" = 15,
                                             "trees" = 8)) +
  labs(title = "ggplot() map of roads, plots and study area",
       subtitle = "with north arrow and scale bar",
       x = "", y = "") + ggsn::blank() +
  ggsn::scalebar(sjer_plots_df, dist = 100, dd2km = FALSE, model = 'WGS84', location = "topright",
                 st.dist = 10, st.size= 10,
                 anchor = c(x = x_scale_loc, y = y_scale_loc))

and the full tutorial is here:
https://earthdatascience.org/course-materials/earth-analytics/week-4/r-make-maps-with-ggplot-in-R/

this is for my students. am i doing something wrong ? i'm getting characters for the scale bar and no bar. i presume i'm doing something wrong but can't seem to figure out what! my data are in UTM meters.
Thank you for any help.

I am trying to use ggsn::scalebar in a script that produces maps that could range in area. The default scalebar labels overlap the scalebar.

Is there a way to ensure that this doesn't happen? st.dist doesn't seem to fit what I am looking for, and it seems like avoiding overlap should be built in by default.

Examples:

 ggsn::scalebar(location="bottomleft",
                 dist = roundup(diff(xlim.set)/10)/1000, #minimum 1/10 of x limits, in km
                 x.min = xlim.set[1],
                 x.max = xlim.set[2],
                 y.min = ylim.set[1],
                 y.max = ylim.set[2],
                 dd2km = F,
                 dist_unit = "km")

  ggsn::scalebar(location="bottomleft",
                 dist = roundup(diff(xlim.set)/10)/1000, #minimum 1/10 of x limits, in km
                 x.min = xlim.set[1],
                 x.max = xlim.set[2],
                 y.min = ylim.set[1],
                 y.max = ylim.set[2],
                 dd2km = F,
                 dist_unit = "km",
                 st.bottom = F)

Hi Oswaldo,
I was wondering if it's possible to place this scalebar off the face of the map; I'd like to place it more visibly and off the map where it won't interfere with the visual, perhaps below the x axis.

Code for the scalebar is:
scalebar(dist = 50, dd2km = TRUE, model = "WGS84",
st.size = 3, location="bottomleft",
x.min=-71.70774,
x.max=-70.63711,
y.min=41.89158,
y.max=42.7862)

First of all, thank you for this package.
When I have multiple layers to plot, I use to write my ggplot layers as is:

ggplot() +
  geom_sf(data = data1) +
  geom_sf(data = data2)

In that case, your scalebar continues to work but not the north arrow.
For instance with your example:

dsn <- system.file('extdata', package = 'ggsn')
# Map in geographic coordinates
map <- st_read(dsn, 'sp', quiet = TRUE)
# Map in projected coordinates
map2 <- st_transform(map, 31983)

ggplot() +
  geom_sf(data = map2, aes(fill = nots)) +
  north(map2, symbol = 16, scale = 0.15) +
  scale_fill_brewer(name = 'Animal abuse\nnotifications', palette = 8) +
  scalebar(map2, dist = 5, dd2km = FALSE)

I do not see where this comes from.

Hello-
I have tried adding a scalebar to a map created in ggplot2, following the code provided in the package documentation, and I have found that the example code no longer works. I've hit the same error when trying to add a scale bar to a map I've created using my own data. Here is the script that I am running, which generates the error. This code is copied and pasted directly from the package documentation file, "ggsn.pdf", page 7:

library(rgdal); library(broom) dsn <- system.file('extdata', package = 'ggsn') map <- readOGR(dsn, 'sp') map@data$id <- 1:nrow(map@data) map.df <- merge(tidy(map), map, by = 'id') ggplot(data = map.df, aes(long, lat, group = group, fill = nots)) + geom_polygon() + coord_equal() + geom_path() + scale_fill_brewer(name = 'Animal abuse\nnotifications', palette = 8) + scalebar(map.df, dist = 5, dd2km = TRUE, model = 'WGS84')

The error that this generates is as follows:

Error in FUN(left, right) : non-numeric argument to binary operator

For reproducibility, here is my RSessionInfo:

`R version 3.3.3 (2017-03-06)
Platform: x86_64-apple-darwin13.4.0 (64-bit)
Running under: macOS Sierra 10.12.3

locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

attached base packages:
[1] stats graphics grDevices utils datasets methods base

other attached packages:
[1] broom_0.4.2 knitr_1.15.1 stringr_1.0.0 readxl_0.1.1 gridExtra_2.2.1
[6] lattice_0.20-34 animation_2.4 dismo_1.0-15 raster_2.5-8 geosphere_1.5-1
[11] wesanderson_0.3.4 scales_0.4.1 maptools_0.9-2 roxygen2_5.0.1 adehabitatHR_0.4.14
[16] adehabitatLT_0.3.20 CircStats_0.2-4 boot_1.3-18 MASS_7.3-45 adehabitatMA_0.3.10
[21] ade4_1.7-4 deldir_0.1-12 rgdal_1.1-10 sp_1.2-4 ggmap_2.6.1
[26] RMySQL_0.10.9 DBI_0.5-1 ggsn_0.4.0 ggplot2_2.2.1 devtools_1.12.0

loaded via a namespace (and not attached):
[1] reshape2_1.4.1 colorspace_1.2-6 foreign_0.8-67 withr_1.0.1 jpeg_0.1-8
[6] plyr_1.8.3 munsell_0.4.3 gtable_0.2.0 RgoogleMaps_1.2.0.7 mapproj_1.2-4
[11] psych_1.7.3.21 memoise_1.0.0 labeling_0.3 parallel_3.3.3 curl_0.9.7
[16] proto_0.3-10 Rcpp_0.12.9 mnormt_1.5-5 rjson_0.2.15 png_0.1-7
[21] digest_0.6.12 stringi_1.1.1 dplyr_0.5.0 RJSONIO_1.3-0 grid_3.3.3
[26] tools_3.3.3 magrittr_1.5 maps_3.1.0 lazyeval_0.2.0 tibble_1.2
[31] tidyr_0.6.0 rsconnect_0.4.3 rstudioapi_0.5 assertthat_0.1 httr_1.1.0
[36] R6_2.2.0 nlme_3.1-131 git2r_0.15.0`

Loading required package: ggsn
Installing package into ‘/gpfs1/homes/uqbababa/.R/library’
(as ‘lib’ is unspecified)
also installing the dependency ‘sf’

trying URL 'https://cloud.r-project.org/src/contrib/sf_0.7-3.tar.gz'
Content type 'application/x-gzip' length 8166770 bytes (7.8 MB)

downloaded 7.8 MB

trying URL 'https://cloud.r-project.org/src/contrib/ggsn_0.5.0.tar.gz'
Content type 'application/x-gzip' length 649649 bytes (634 KB)

downloaded 634 KB

• installing source package ‘sf’ ...
  ** package ‘sf’ successfully unpacked and MD5 sums checked
  configure: CC: icc -std=gnu99
  configure: CXX: icpc -std=gnu++11
  checking for gdal-config... /opt/gdal/bin/gdal-config
  checking gdal-config usability... yes
  configure: GDAL: 2.2.0
  checking GDAL version >= 2.0.0... yes
  checking for gcc... icc -std=gnu99
  checking whether the C compiler works... yes
  checking for C compiler default output file name... a.out
  checking for suffix of executables...
  checking whether we are cross compiling... no
  checking for suffix of object files... o
  checking whether we are using the GNU C compiler... yes
  checking whether icc -std=gnu99 accepts -g... yes
  checking for icc -std=gnu99 option to accept ISO C89... none needed
  checking how to run the C preprocessor... icc -std=gnu99 -E
  checking for grep that handles long lines and -e... /usr/bin/grep
  checking for egrep... /usr/bin/grep -E
  checking for ANSI C header files... yes
  checking for sys/types.h... yes
  checking for sys/stat.h... yes
  checking for stdlib.h... yes
  checking for string.h... yes
  checking for memory.h... yes
  checking for strings.h... yes
  checking for inttypes.h... yes
  checking for stdint.h... yes
  checking for unistd.h... yes
  checking gdal.h usability... yes
  checking gdal.h presence... yes
  checking for gdal.h... yes
  checking GDAL: linking with --libs only... yes
  checking GDAL: /opt/gdal/share/gdal/pcs.csv readable... yes
  checking GDAL: checking whether PROJ is available for linking:... yes
  checking GDAL: checking whether PROJ is available fur running:... yes
  checking proj_api.h usability... no
  checking proj_api.h presence... no
  checking for proj_api.h... no
  configure: error: proj_api.h not found in standard or given locations.
  ERROR: configuration failed for package ‘sf’
• removing ‘/gpfs1/homes/uqbababa/.R/library/sf’
  ERROR: dependency ‘sf’ is not available for package ‘ggsn’
• removing ‘/gpfs1/homes/uqbababa/.R/library/ggsn’

The downloaded source packages are in
‘/gpfs1/scratch/30days/uqbababa/RtmpQeDgXO/downloaded_packages’
Warning messages:
1: In library(package, lib.loc = lib.loc, character.only = TRUE, logical.return = TRUE, :
there is no package called ‘ggsn’
2: In install.packages("ggsn") :
installation of package ‘sf’ had non-zero exit status
3: In install.packages("ggsn") :
installation of package ‘ggsn’ had non-zero exit status

Hello,
I have generated a map in ggplot, but plotted only the area between two sets of coordinates and would like to apply a scalebar. Using the x.min x.max etc. commands, the scale bar does appear, however no text appears.
The warning message "Removed 3 rows containing missing values (geom_text)." appears whenever my code is run.

Below is an example, apologies if it is not suitable. Please let me know if there are any issues with it:

`install.packages('mapdata','maps','maptools')
devtools::install_github("dkahle/ggmap")
library(ggplot2)
library(ggmap)
library(maptools)
library(maps)
library(mapdata)
library(ggsn)

japan <- map_data('japan')

JapanMap <- ggplot() +
geom_polygon(data = japan, aes(x = long, y = lat, group = group)) +
xlim(c(138, 144)) + ylim(c(35, 42)) +
scalebar(x.min = 138, x.max = 144,
y.min = 35, y.max = 42,
dist = 50, dd2km = T, model = 'WGS84', location = 'bottomright',
anchor = c(x = 144, y = 35, st.size = 3))`

Attached is the resultant map with scalebar but missing text

Many thanks,

Aran

library(ggmap)
library(ggplot2)
library(ggsn)


register_google(key = APIKEY)

map_saosebast <- ggmap(get_googlemap("sao sebastiao, sp, brazil",
                                     scale = 2, zoom = 12,
                                     maptype ='terrain',
                                     color = 'color'))

x_lim <- map_saosebast$data[c(1, 4), 1] * c(1, .9998)
y_lim <- map_saosebast$data[c(1, 4), 2] * c(1.003, 1)

map_saosebast + scalebar(x.min = x_lim[1], x.max = x_lim[2],
                        y.min = y_lim[1], y.max = y_lim[2],
                        dist = 1, dist_unit = 'km', transform = TRUE, model = 'WGS84')

Warning messages:
1: In min(x) : no non-missing arguments to min; returning Inf
2: In max(x) : no non-missing arguments to max; returning -Inf
3: In min(x) : no non-missing arguments to min; returning Inf
4: In max(x) : no non-missing arguments to max; returning -Inf
5: Removed 3 rows containing missing values (geom_text). 

> sessionInfo()
R version 3.6.1 (2019-07-05)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows 10 x64 (build 17763)

Matrix products: default

locale:
[1] LC_COLLATE=English_United States.1252  LC_CTYPE=English_United States.1252    LC_MONETARY=English_United States.1252
[4] LC_NUMERIC=C                           LC_TIME=English_United States.1252    

attached base packages:
[1] grid      stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] ggsn_0.5.3    ggmap_3.0.0   ggplot2_3.2.1

loaded via a namespace (and not attached):
 [1] Rcpp_1.0.2         pillar_1.4.2       compiler_3.6.1     plyr_1.8.4         class_7.3-15       bitops_1.0-6      
 [7] tools_3.6.1        digest_0.6.20      jsonlite_1.6       tibble_2.1.3       gtable_0.3.0       lattice_0.20-38   
[13] pkgconfig_2.0.2    png_0.1-7          rlang_0.4.0        DBI_1.0.0          rstudioapi_0.10    curl_4.0          
[19] e1071_1.7-2        withr_2.1.2        dplyr_0.8.3        httr_1.4.1         stringr_1.4.0      RgoogleMaps_1.4.4 
[25] classInt_0.4-1     tidyselect_0.2.5   glue_1.3.1         sf_0.7-7           R6_2.4.0           jpeg_0.1-8        
[31] foreign_0.8-71     sp_1.3-1           purrr_0.3.2        tidyr_0.8.3        magrittr_1.5       units_0.6-4       
[37] scales_1.0.0       maptools_0.9-5     assertthat_0.2.1   colorspace_1.4-1   labeling_0.3       KernSmooth_2.23-15
[43] stringi_1.4.3      lazyeval_0.2.2     munsell_0.5.0      crayon_1.3.4       rjson_0.2.20 

Map plots, but no scalebar. Using the values by hand in x.min, etc, produces the same error.

There seems to be a problem in the scalebar() function when the underlying data are simple features and the plot is faceted.

Reproducible example:

library(ggsn); library(sf)
dsn <- system.file('extdata', package = 'ggsn')

# Map in geographic coordinates
map <- st_read(dsn, 'sp', quiet = TRUE)

(ggm1 <- ggplot(map, aes(fill = nots)) +
    geom_sf() +
    scale_fill_brewer(name = 'Animal abuse\nnotifications', palette = 8))

ggm1 +
  blank() +
  facet_grid(~ nots) + 
  north(map) +
  scalebar(map, dist = 5, dd2km = TRUE, model = 'WGS84',
           facet.var = "nots", facet.lev = "[0,10]")

Throws this error:

Error in sort.list(y) : 'x' must be atomic for 'sort.list'
Have you called 'sort' on a list?

It seems that this line in scalebar():

data[, facet.var[i]] <- factor(data[, facet.var[i]])

is the culprit and breaks because data[, facet.var[i]] returns a simple features data frame containing two variables, nots and geometry. It makes sense to change the right hand side to pull(data, facet.var[i]) but I'm not sure about the best way to change the underlying class to factor on the left hand side. There are also several other spots in the code where factor(data[, facet.var[i]]) should also use pull().

I wanted to show scalebar on only one of the facets, but my variable is numeric (years). In that case, selecting a facet adds a new empty facet. I think this maybe due to the transformation to factors in your code. Maybe, you may want to use as.factor(as.character(...)) at some places.
Example:

library(dplyr)
library(ggsn); library(sf)
dsn <- system.file('extdata', package = 'ggsn')

# Map in geographic coordinates
map <- st_read(dsn, 'sp', quiet = TRUE)
map2 <- map %>% 
  mutate(years = as.numeric(nots) + 2000)

ggplot(map2, aes(fill = nots)) +
  geom_sf() +
  blank() +
  facet_grid(~years) + 
  north(map2) +
  scalebar(map2, dist = 5, dd2km = TRUE, model = 'WGS84',
           facet.var = "years", facet.lev = '2001')

Here is an example.

library(ggsn)
library(ggplot2)

levls = c("A", "B", "C")
tmp_data= expand.grid(type = levls,
            long = 1:10)
tmp_data$lat = runif(10)

tmp_data$type = factor(tmp_data$type, levels = levls[c(2,1,3)])

g = ggplot(data = tmp_data, aes(x = long, y = lat)) + facet_grid(.~type) + geom_point()
g

g + scalebar(data = tmp_data, location = "topright", facet.var = "type", 
             facet.lev = "B", dd2km = FALSE,dist = 0.1)

I'd like to be able to conserve a specific order for the levels in the facetting variable. However, using scalebar seems to rearrange them into alphabetical order.

Hi there.
First of all, thanks for the package.

I just wanted to point out an issue with the package gganimate. While the scale bar works fine for static plots, for some reason it gives problems for animated plots.

Here is a reproducible example inspired from your Readme:

library(ggsn); library(ggplot2); library(sf); library(gganimate)
#> Loading required package: ggplot2
#> Loading required package: grid
#> Linking to GEOS 3.5.1, GDAL 2.1.3, PROJ 4.9.2
data("domestic_violence")
(ggm1 <- ggplot(domestic_violence, aes(fill = Scaled)) +
    geom_sf() +
    scale_fill_continuous(low = "#fff7ec", high = "#7F0000") +
    ggsn::scalebar(domestic_violence, dist = 4, dist_unit = "km",
             transform = TRUE, model = "WGS84"))

gganimate::animate(
  ggm1 + transition_states(Value),
  nframes = 5
)

^{Created on 2019-04-17 by the reprex package (v0.2.1)}

As you can see, the scale bar is not rendered properly in all of the images of the animations. Furthermore, it raises an error when using transition_time() that I suspect must be due to the same underlying cause.

In ggsn v0.5.0, the scalebar() function will fail if the names of the columns containing latitude and longitude data do not start with lat and long, respectively:

library(ggmap)
library(ggsn)

coords <- 
    data.frame(stringsAsFactors = FALSE,
               x = c(150.750034, 150.6857303, 150.533333, 150.416667, 150.279,
                     150.3730633, 150.5625494, 150.65),
               y = c(-33.613769, -33.5801886, -33.5, -33.55, -33.514, -33.7094058,
                     -33.7002999, -33.666667))

head(coords)

#>          x         y
#> 1 150.7500 -33.61377
#> 2 150.6857 -33.58019
#> 3 150.5333 -33.50000
#> 4 150.4167 -33.55000
#> 5 150.2790 -33.51400
#> 6 150.3731 -33.70941

my_map <- qmplot(x, y, data = coords, geom = "blank", 
                 maptype = "terrain-background", zoom = 11)

my_map + 
    scalebar(data = coords, dist = 5, dist_unit = "km", model = "WGS84", 
             transform = TRUE)

#> Warning in min(data$long): no non-missing arguments to min; returning Inf
#> Warning in max(data$long): no non-missing arguments to max; returning -Inf
#> Warning in min(data$lat): no non-missing arguments to min; returning Inf
#> Warning in max(data$lat): no non-missing arguments to max; returning -Inf
#> Warning in sin(lat): NaNs produced
#> Warning in cos(phi): NaNs produced
#> Warning in sin(phi): NaNs produced

#> Warning in sin(phi): NaNs produced
#> Warning in sin(lat): NaNs produced
#> Warning in cos(phi): NaNs produced
#> Warning in sin(phi): NaNs produced

#> Warning in sin(phi): NaNs produced
#> `data` must be uniquely named but has duplicate columns

And no map will be generated. Compare this to the magic names:

names(coords) <- c("long", "lat")

my_map + 
    scalebar(data = coords, dist = 5, dist_unit = "km", model = "WGS84", 
             transform = TRUE)

I am ploting a map using the ggplot2 and sf packages and I would like to include a map scale and north arrow to the figure using the ggsn package. Here is the problem. I want to show a figure with two or more facets but I would like to add the scale and north arrow to only one of the figure facets.

I've detailed my question here. . I'm not sure this should be created as an issue .

I'd like to change border size and colors of the scalebar. I thought it would be possible to add "color", "fill" and "border.size" arguments to the code, unfortunately it s not. Any pointers?

I am trying to reproduce the first example of adding north and scalebar on my macOS,

library(ggsn)
library(sf)
dsn <- system.file('extdata', package = 'ggsn')

# Map in geographic coordinates
map <- st_read(dsn, 'sp', quiet = TRUE)

# Map in projected coordinates
map2 <- st_transform(map, 31983)

(ggm1 <- ggplot(map, aes(fill = nots)) +
    geom_sf() +
    scale_fill_brewer(name = 'Animal abuse\nnotifications', palette = 8))

ggm1 +
  blank() +
  north(map) +
  scalebar(map, dist = 5, dd2km = TRUE, model = 'WGS84')

but it gives following error

Error in grid.Call.graphics(C_setviewport, vp, TRUE) : 
  non-finite location and/or size for viewport
In addition: There were 21 warnings (use warnings() to see them)
> warnings()
Warning messages:
1: In max(data$long) : no non-missing arguments to max; returning -Inf
2: In min(data$long) : no non-missing arguments to min; returning Inf
3: In max(data$lat) : no non-missing arguments to max; returning -Inf
4: In min(data$lat) : no non-missing arguments to min; returning Inf
5: In max(data$long) : no non-missing arguments to max; returning -Inf
6: In max(data$lat) : no non-missing arguments to max; returning -Inf
7: In max(data$long) : no non-missing arguments to max; returning -Inf
8: In min(data$lat) : no non-missing arguments to min; returning Inf
9: In max(data$lat) : no non-missing arguments to max; returning -Inf
10: In min(data$lat) : no non-missing arguments to min; returning Inf
11: In max(data$lat) : no non-missing arguments to max; returning -Inf
12: In min(data$lat) : no non-missing arguments to min; returning Inf
13: In sin(lat) : NaNs produced
14: In cos(phi) : NaNs produced
15: In sin(phi) : NaNs produced
16: In sin(phi) : NaNs produced
17: In sin(lat) : NaNs produced
18: In cos(phi) : NaNs produced
19: In sin(phi) : NaNs produced
20: In sin(phi) : NaNs produced
21: Removed 2 rows containing missing values (geom_text).

My session information is as follows

> sessionInfo()
R version 3.4.1 (2017-06-30)
Platform: x86_64-apple-darwin16.7.0 (64-bit)
Running under: macOS Sierra 10.12.6

Matrix products: default
BLAS: /System/Library/Frameworks/Accelerate.framework/Versions/A/Frameworks/vecLib.framework/Versions/A/libBLAS.dylib
LAPACK: /System/Library/Frameworks/Accelerate.framework/Versions/A/Frameworks/vecLib.framework/Versions/A/libLAPACK.dylib

locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] sf_0.5-4           ggsn_0.4.0         ggplot2_2.2.1.9000

loaded via a namespace (and not attached):
 [1] Rcpp_0.12.12       lattice_0.20-35    png_0.1-7          digest_0.6.12      grid_3.4.1        
 [6] plyr_1.8.4         DBI_0.7            gtable_0.2.0       magrittr_1.5       units_0.4-6       
[11] scales_0.5.0.9000  rlang_0.1.2        lazyeval_0.2.0     sp_1.2-5           RColorBrewer_1.1-2
[16] tools_3.4.1        udunits2_0.13      foreign_0.8-69     munsell_0.4.3      yaml_2.1.14       
[21] compiler_3.4.1     colorspace_1.3-2   maptools_0.9-2     tibble_1.3.4

Hi. I often use small ggmaps with high Google API scale value, where 1km scales are definitely too much. Is it possible to use values of scale size lower than 1, like 100m?
Thanks

First off, I am super excited about this package! Thanks for all the work. I have been trying to get a scalebar on my own map and kept on getting various errors. So I ran through your example and got this
Error in FUN(left, right) : non-numeric argument to binary operator
After running
ggm1 + blank() + north(map.df) + scalebar(map.df, dist = 5, dd2km = TRUE, model = 'WGS84')

from your example. the creation of ggm1 worked just fine. This is the same error I get when I try to add a scalebar to my own map. Thoughts? Thanls

When I try to use ggsn on a ggplot-map, I get an error when using coord_map. I do see that certain map projections might cause an error (where to point to north on a globe for example), but in the default map projection it would not cause an issue (as far as I understand it).

Here is an example:

library(ggsn)
#> Loading required package: ggplot2

# following loosely the example in ?map_data (ggplot2)

## Data Preparation
states <- map_data("state")
arrests <- USArrests
names(arrests) <- tolower(names(arrests))
arrests$region <- tolower(rownames(USArrests))

choro <- merge(states, arrests, sort = FALSE, by = "region")
choro <- choro[order(choro$order), ]

# Map Creation
figure_map <- ggplot(choro, aes(long, lat)) +
  geom_polygon(aes(group = group, fill = assault))

The base map without coord map

## A minimum case
figure_map

figure_map + north(choro, symbol = 16, scale = 0.15)

Map + coord map

## Coordinates of a Map
figure_map + coord_map()

figure_map + coord_map() + north(choro, symbol = 16, scale = 0.15)
#> Error: annotation_custom only works with Cartesian coordinates

Any chance to fix this easily?

Hello,
How can I add a scale bar to a ggplot map where the axes have been modified? Here is what I have tried:

Code to generate data frame:

options(scipen = 12)
lib <- c("raster", "rgdal", "ggplot2", "ggsn")
sapply(lib, function(x) require(x, character.only = TRUE))
nz1 <- getData("GADM", country = "NZ", level = 1)
nz1 <- spTransform(nz1, CRS("+init=epsg:2135"))
nz1@data$id <- rownames(nz1@data)
nz1.ff <- fortify(nz1)
nz1.df <- merge(nz1@data, nz1.ff, by = "id", all.y = TRUE)
colnames(nz1.df)[7] <- "Region"

Tried this first, no dice:

mapNZ <- ggplot() +
        geom_polygon(data=nz1.df, aes(x=long, y=lat, fill = Region, group=group), size = 0.1) + scale_x_continuous(limits = c(-400000, 650000)) + scale_y_continuous(limits = c(-4500000, 6250000))
      theme_bw() + theme(text = element_text(size=50))

x_lim <- mapNZ$nz1.df[c(-400000, 650000), 1] * c(1, .9998)
y_lim <- mapNZ$nz1.df[c(-4500000, 6250000), 2] * c(1.003, 1)

mapNZ  + scalebar(x.min = x_lim[1], x.max = x_lim[2],
       y.min = y_lim[1], y.max = y_lim[2], dist = 200, st.size = 20) 

Then I replaced scale_x_continuous() and scale_y_continuous() with coord_cartesian(), as that seems to be the fix for similar issues, but that didn't work either. It doesn't throw an error, the scale bar just doesn't show up. Can you suggest anything? Thanks!

This error message even occurs with the examples provided.

How can I get around this?

Thanks

Is there any way to change the units of a scalebar from km to miles?

Using ggsn 0.5.0:

When creating a map with ggplot() and geom_sf() and using scalebar(), if your sf data object has a column named label, the information in that column is used instead of the proper unit labels specified in scalebar(). For example:

library(sf)
library(tidyverse)
library(ggsn)
library(maps)
library(ggplot2)

st <- st_as_sf(map("state", plot=FALSE, fill=TRUE)) %>%
  filter(ID %in% c("connecticut","massachusetts","new hampshire")) %>%
  mutate(label=c("CN","MA","NH"))

ggplot(data=st) +
  geom_sf() +
  scalebar(data=st, dist_unit="km", dist=100, transform=T)

You can work around this by changing the name of the column in the sf object to anything else, e.g.

st <- st %>% rename(.label = label)

ggplot(data=st) +
  geom_sf() +
  scalebar(data=st, dist_unit="km", dist=100, transform=T)

Naming the label column scalebar() creates to something other than label and less likely to overlap with sf column names should solve this. I can write a PR if you want.

In ggsn v0.5.0, the presence of extra columns will make scalebar() fail when it is time to pipe it together with a ggplot object:

library(ggmap)
library(ggsn)

coords <- 
    data.frame(stringsAsFactors = FALSE,
               long  = c(150.750034, 150.6857303, 150.533333, 150.416667, 150.279,
                         150.3730633, 150.5625494, 150.65),
               lat   = c(-33.613769, -33.5801886, -33.5, -33.55, -33.514, 
                         -33.7094058, -33.7002999, -33.666667),
               label = c("WSU", "Grose Vale", "Bilpin", "Mt Tomah", "Bell",
                         "Katoomba", "Springwood", "Hawkesbury Heights"))

head(coords)

#>       long       lat      label
#> 1 150.7500 -33.61377        WSU
#> 2 150.6857 -33.58019 Grose Vale
#> 3 150.5333 -33.50000     Bilpin
#> 4 150.4167 -33.55000   Mt Tomah
#> 5 150.2790 -33.51400       Bell
#> 6 150.3731 -33.70941   Katoomba

my_map <- qmplot(long, lat, data = coords, geom = "blank", 
                 maptype = "terrain-background", zoom = 11)

my_map + 
    scalebar(data = coords, dist = 5, dist_unit = "km", model = "WGS84", 
             transform = TRUE)
#> `data` must be uniquely named but has duplicate columns

And a blank map (white rectangle) is generated. But when the extra column(s) are removed:

my_map + 
    scalebar(data = coords[c("long", "lat")], dist = 5, dist_unit = "km", 
             model = "WGS84", transform = TRUE)

Hi Oswaldo,

I'm trying to add a scale bar to a ggplot object that includes several layers. There is an sf object (read from a shapefile using st_read( ) ) that I want to use to produce the scale bar. Here is my code and the error:

ggplot( prediction ) + theme_bw() + geom_raster( aes( Longitude , Latitude , fill = Probability )) + scale_fill_viridis( option = "B" , limits = c( 0, 0.6 )) + geom_sf(data=counties, color="gray5", fill="NA", cex=0.1) + geom_contour( aes( x=Longitude , y=Latitude , z=p) , breaks = c( 0.025 ), color="Blue" , cex=1.2, lty=1) + geom_contour( aes( x=Longitude , y=Latitude , z=p) , breaks = c( 0.975 ), color="Red" , cex=1.2, lty=1) + geom_sf(data=buffer, color="black", fill="NA", cex=2) + scalebar(data=buffer, dist = 25, dd2km = TRUE, x.min=-79.83613, x.max=-78.04790, y.min=35.11765, y.max=36.89916, model = "WGS84")

Here's the error:
Warning messages:
1: In max(data$long) : no non-missing arguments to max; returning -Inf
2: In min(data$lat) : no non-missing arguments to min; returning Inf
3: In max(data$lat) : no non-missing arguments to max; returning -Inf
4: In min(data$lat) : no non-missing arguments to min; returning Inf
5: In max(data$lat) : no non-missing arguments to max; returning -Inf
6: In min(data$lat) : no non-missing arguments to min; returning Inf

The map plots fine otherwise, but with no scale bar

north(ggmap(get_googlemap()) produces above error.
:(

Hi!

I'm using coord_map() instead of coord_equal() to select a segment of a map. Do you know any way to use ggsn with it?.

Thank you for your work!

Hi,
I am trying to update the ggsn (0.4.0) package in order to use north( ) and avoid the error "Error: annotation_custom only works with Cartesian coordinates", but every time that I run the github instalation I get this error:
Error: C:/Users/bmped/AppData/Local/Temp/RtmpWmL5pz/devtoolseb448a42356/oswaldosantos-ggsn-f0fd534/man/scalebar.Rd:54: Bad \link text

• removing 'C:/Users/bmped/Documents/R/win-library/3.4/ggsn'
• restoring previous 'C:/Users/bmped/Documents/R/win-library/3.4/ggsn'

I wonder, how can I solve it?
Thank you!
Thank you!

Hi Oswaldo, the scalebar function is great, but I was wondering if there is currently a way to change the number of labels (i.e. the number of scales), ideally from 3 to 2 whereby only "0" and the maximum scale is drawn. For example, on the map below only display 0 and 8km. This would be useful because sometimes in small scales the middle label isn't required and gets in the way.

Example

library(ggsn); library(ggplot2); library(sf)
data("domestic_violence")
(ggm1 <- ggplot(domestic_violence, aes(fill = Scaled)) +
geom_sf() +
scale_fill_continuous(low = "#fff7ec", high = "#7F0000"))
ggm1 + north(domestic_violence) + scalebar(domestic_violence, dist = 4, dist_unit = "km", transform = TRUE, model = "WGS84")

The sf package is the R implementation of Simple Features and starts to be a new standard for working with spatial data in R. More information at https://github.com/edzer/sfr and http://robinlovelace.net/geocompr/spatial-class.html.

Moreover, the development version of ggplot2 package already supports plots with sf object using a geom_sf() function - http://ggplot2.tidyverse.org/reference/ggsf.html. I think it could be very useful to have a possibility to add a north arrow and scale bar to maps with sf objects.

@oswaldosantos do you plan to add a support for sf objects?

I've installed ggsn 0.4.6 and ggplot2 2.2.1.9000. When I try to run the example code:

library(ggsn); library(sf)
dsn <- system.file('extdata', package = 'ggsn')

# Map in geographic coordinates
map <- st_read(dsn, 'sp', quiet = TRUE)

ggm1 +
    blank() +
    north(map) +
    scalebar(map, dist = 5, dd2km = TRUE, model = 'WGS84')

I get:

Error: GeomCustomAnn was built with an incompatible version of ggproto.
Please reinstall the package that provides this extension.

My session info:

R version 3.4.2 (2017-09-28)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows >= 8 x64 (build 9200)

Attached base packages:
[1] grid      stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] sf_0.5-5           ggsn_0.4.6         ggplot2_2.2.1.9000

In ggsn v0.5.0, the scalebar() function does not warn the user if the dist argument is too large for the map. This results in part of the scalebar being cut off (if dist goes off the edge of the plot area on only one edge) or the entire bar just going missing if dist is large enough that both sides go outside the plot area:

library(ggmap)
library(ggsn)

coords <- 
    data.frame(stringsAsFactors = FALSE,
               long  = c(150.750034, 150.6857303, 150.533333, 150.416667, 150.279,
                         150.3730633, 150.5625494, 150.65),
               lat   = c(-33.613769, -33.5801886, -33.5, -33.55, -33.514, 
                         -33.7094058, -33.7002999, -33.666667))

head(coords)

#>       long       lat
#> 1 150.7500 -33.61377
#> 2 150.6857 -33.58019
#> 3 150.5333 -33.50000
#> 4 150.4167 -33.55000
#> 5 150.2790 -33.51400
#> 6 150.3731 -33.70941

my_map <- qmplot(long, lat, data = coords, geom = "blank", 
                 maptype = "terrain-background", zoom = 11)

my_map + 
    scalebar(data = coords, dist = 22, dist_unit = "km", model = "WGS84", 
             transform = TRUE, location = "bottomleft")

This is the extent of this map, about 44 km wide.

my_map + 
    scalebar(data = coords, dist = 25, dist_unit = "km", model = "WGS84", 
             transform = TRUE, location = "bottomleft")
#> Warning: Removed 1 rows containing missing values (geom_text).

The right half of the scale bar cannot fit in the plot area.

my_map + 
    scalebar(data = coords, dist = 25, dist_unit = "km", model = "WGS84", 
             transform = TRUE, location = "bottomright")
#> Warning: Removed 1 rows containing missing values (geom_text).

The left half cannot fit.

my_map + 
    scalebar(data = coords, dist = 2500, dist_unit = "km", model = "WGS84", 
             transform = TRUE, location = "bottomright")
#> Warning in min(x): no non-missing arguments to min; returning Inf
#> Warning in max(x): no non-missing arguments to max; returning -Inf
#> Warning: Removed 2 rows containing missing values (geom_text).

This is what happens when neither half of the scale bar can fit.

my_map + 
    scalebar(data = coords, dist = 1, dist_unit = "m", model = "WGS84", 
             transform = TRUE, location = "bottomright")

And the above too-large example looks very much like this too-small example.

Thank your for the great package! I am using it regularly.
I recently created a map with a scale bar of 100m. The labels were 0.05 and 0.1km.
Is there any way to change the label format to meters?
I think this would be a useful option for users.

Any way to adjust the line width on the scale bar? Looks good in plot window, but when exported as a postscript file, the line width is too wide. I see you can adjust text size with st.size, but don't see a way of adjusting line width.

Using the latest sf:

library(ggsn); library(sf); library(ggplot2)
dsn <- system.file('extdata', package = 'ggsn')
map <- st_read(dsn, 'sp', quiet = TRUE)
map2 <- st_transform(map, 31983)
ggm1 <- ggplot(map, aes(fill = nots)) +
    geom_sf() +
    scale_fill_brewer(name = 'Animal abuse\nnotifications', palette = 8)
ggm1 +
    blank() +
    north(map)

Returns:

Error in grid.Call.graphics(C_setviewport, vp, TRUE) : 
  non-finite location and/or size for viewport

Also, ggm1 + scalebar(map, dist = 5, dd2km = TRUE, model = 'WGS84') does not show any scalebar.

I updated to the latest development version ggsn (0.5.1) and I get this error.

Error in st_geometry<-.data.frame(tmp, value = NULL) : inherits(value, "sfc") || is.character(value) is not TRUE

The error is the same as the one described in this stack exchange post. It seems there is some issue with the line st_geometry(legend2) <- NULL.

https://stackoverflow.com/questions/55943227/new-error-when-fitting-a-ggsn-scale-bar-to-ggmap-object

Also, I believe that the sf library should be prefixed to the st_geometry call, so that users don't need to load sf library themselves. e.g. sf:st_geometry(legend2). After loading the sf library, I get the above message.

Blz cara... muito obrigado! This is great!

I was wondering... it could be really useful to also allow for a title block. .. expandable to title and author... etc.. that way the scale bar, legend, and title block could all be optionally combined?

If we can do all that and add a border, i think R maps could really compete with any software package!

Can't load this package

my code:

%load_ext rpy2.ipython

%%R
install.packages(c("ggplot2", "devtools", "dplyr", "stringr"))
install.packages(c("maps", "mapdata", "ggmap", "sf", "gssn")) 

%%R
library(ggplot2)
library(ggmap)
library(maps)
library(mapdata)
library(gssn) 

RInterpreterError: Failed to parse and evaluate line 'library(ggsn)\n'.
R error message: 'Error in library(ggsn) : there is no package called ‘ggsn’'

This happens on colab, and R studio (version 4.0.2 (2020-06-22)). I've allso tried the devtools install and still get the same error.

Hi,
could you clarify which projection are you using to define the scale bar? a standard plate carée?
I couldn't seem to find what I was looking for in the code.
Thanks

Hi Oswaldo - Feature request rather than issue. It would be great to add support for terra raster datasets to be used as the 'data' used for creating the ggplot in ggsn::north and ggsn::scalebar. At the moment I have to manually extract the extents using terra::ext and then set them in using x.min, x.max, y.min, y.max. Hopefully quite an easy one to implement and would remove an annoying step. Thanks!

I'm adding a scale bar (using the ggsn package) to a map that is faceted. I can't quite figure out how to correctly use the facet.var variable. I currently can successfully add a scalebar that appears on all facets, but cannot restrict it to a single facet (get the undefined columns selected error). It looks like the examples are for facet_grid, and I can't quite replicate the result with facet_wrap. Any help would be appreciated...

An example of my issue:

library(ggmap)
library(ggsn)

Finalmap <- get_map(location = c(lon = -23.17, lat = 15.2), zoom = 11,  
                maptype = "hybrid", scale = 2)

data <- expand.grid(x = -23.17, y = 15.2, Factor = c("A", "B", "C"))
    
ggmap(Finalmap) +
    geom_point(data = data, aes(x = x, y = y)) +
    facet_wrap(~ Factor) +
    scalebar(dist = 3, dist_unit = "km",
            x.min = -23.2, x.max = -23.1, y.min = 15.1, y.max = 15.3,
            anchor = c(x = -23.12, y = 15.12),
            height = 0.04, st.dist = 0.1,
            st.color = "white", 
         transform = TRUE, model = "WGS84",
#### THESE TWO LINES ARE THE PROBLEM
         facet.var = c("Factor"), 
         facet.lev = "C")

Hi,

My plotting code that used ggsn::scalebar fine last year stopped working until I made a minor change, replacing dd2km with transform. The documentation doesn't explain this.

See https://stackoverflow.com/questions/58510360/i-am-looking-to-add-a-scalebar-to-my-ggmap-in-r-but-keep-getting-transform-sho/62901185#62901185.

Thanks for the package - otherwise works great!

Hello,
it seems like the package is not working anymore. If I execute the example-code, I get this error-message
Error in grid.Call.graphics(C_setviewport, vp, TRUE) : non-finite location and/or size for viewport In addition: There were 21 warnings (use warnings() to see them)

Example Code

dsn <- system.file('extdata', package = 'ggsn')
map <- st_read(dsn, 'sp', quiet = TRUE)
map2 <- st_transform(map, 31983)

(ggm1 <- ggplot(map, aes(fill = nots)) +
    geom_sf() +
    scale_fill_brewer(name = 'Animal abuse\nnotifications', palette = 8))

ggm1 +
  blank() +
  north(map) +
  scalebar(map, dist = 5, dd2km = TRUE, model = 'WGS84')```

Here is my session info

```r 
sessionInfo()
R version 3.5.0 (2018-04-23)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows >= 8 x64 (build 9200)

Matrix products: default

locale:
[1] LC_COLLATE=English_Australia.1252  LC_CTYPE=English_Australia.1252   
[3] LC_MONETARY=English_Australia.1252 LC_NUMERIC=C                      
[5] LC_TIME=English_Australia.1252    

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] sf_0.6-3      ggsn_0.4.0    ggplot2_3.0.0

loaded via a namespace (and not attached):
 [1] Rcpp_0.12.18       RColorBrewer_1.1-2 pillar_1.3.0       compiler_3.5.0     plyr_1.8.4        
 [6] bindr_0.1.1        class_7.3-14       tools_3.5.0        digest_0.6.15      tibble_1.4.2      
[11] gtable_0.2.0       lattice_0.20-35    pkgconfig_2.0.1    png_0.1-7          rlang_0.2.1       
[16] DBI_1.0.0          rstudioapi_0.7     yaml_2.1.19        bindrcpp_0.2.2     spData_0.2.9.0    
[21] e1071_1.6-8        withr_2.1.2        dplyr_0.7.6        classInt_0.2-3     grid_3.5.0        
[26] tidyselect_0.2.4   glue_1.3.0         R6_2.2.2           foreign_0.8-70     sp_1.3-1          
[31] purrr_0.2.5        magrittr_1.5       scales_0.5.0       maptools_0.9-2     units_0.6-0       
[36] assertthat_0.2.0   colorspace_1.3-2   lazyeval_0.2.1     munsell_0.5.0      crayon_1.3.4  `

Hi,

I keep getting the following error message when attempting to install 'ggsn':
##########################
double free or corruption (out)
Aborted (core dumped)
#########################

which seems to suggest "insufficient package version (submitted: 0.5.0, existing: 0.5.0)

I have attached log files and session info.

Many thanks for your help, I look forward to using the package.

Best,

Dylan

Session Info:
R version 4.0.2 (2020-06-22)
Platform: x86_64-pc-linux-gnu (64-bit)
Running under: Ubuntu 20.04.1 LTS

Matrix products: default
BLAS: /usr/lib/x86_64-linux-gnu/blas/libblas.so.3.9.0
LAPACK: /usr/lib/x86_64-linux-gnu/lapack/liblapack.so.3.9.0

locale:
[1] LC_CTYPE=en_US.UTF-8 LC_NUMERIC=C
[3] LC_TIME=es_CL.UTF-8 LC_COLLATE=en_US.UTF-8
[5] LC_MONETARY=es_CL.UTF-8 LC_MESSAGES=en_US.UTF-8
[7] LC_PAPER=es_CL.UTF-8 LC_NAME=C
[9] LC_ADDRESS=C LC_TELEPHONE=C
[11] LC_MEASUREMENT=es_CL.UTF-8 LC_IDENTIFICATION=C

attached base packages:
[1] stats graphics grDevices utils datasets methods base

loaded via a namespace (and not attached):
[1] compiler_4.0.2

00check.txt
00install.txt

Hi,
I use ggsn from time to time to make maps, and I'm pretty sure it should be more famous than it is. As it's very useful.
I stumbled upon the ggplot2-exts repository https://github.com/ggplot2-exts/ggplot2-exts.github.io that makes a searchable gallery for ggplot2 extensions.
Would you consider to make a PR to add ggsn to the list of ggplot2 extensions?

Thanks again for building ggsn!

How can I add a N arrow and scale to maps obtained directly from the web with ggmap? For example:

library(ggmap)
library(ggsn)


myLocation <-  c(lon = 98.883060, lat = 8.167072)
myMap <- get_googlemap(center = myLocation,
              zoom = 11,
              scale = 2, 
              maptype = "terrain",
              markers = data.frame(t(myLocation)))


close_up <- ggmap(myMap)

I'm not sure what to put in here:

close_up +
    blank() +
    north(???) +
    scalebar(???, dist = 5, dd2km = TRUE, model = 'WGS84')

What do you recommend? It would be great to have an example of this in the docs!

If I want to keep the scalebar on all facets, text appears in a weird way:

library(ggsn); library(sf)
dsn <- system.file('extdata', package = 'ggsn')

# Map in geographic coordinates
map <- st_read(dsn, 'sp', quiet = TRUE)

(ggm1 <- ggplot(map, aes(fill = nots)) +
    geom_sf() +
    scale_fill_brewer(name = 'Animal abuse\nnotifications', palette = 8))

ggm1 +
  blank() +
  facet_grid(~nots) + 
  north(map) +
  scalebar(map, dist = 5, dd2km = TRUE, model = 'WGS84')