On Mon, 18 Feb 2019, Miluji Sb wrote:
Dear all,
I am trying to plot coordinates on a world map with Robinson CRS. While the
world map is generated without any issues, when I try to plot the points -
I only get a single point.
Well, the point is correct, since you didn't project df, did you? This
seems to be typical of the arcane nature of ggplot invocations. Did you
try tmap? Almost all the loaded&attached packages are superfluous too.
Roger
The code I am using and the coordinates data is below. What am I doing
wrong? Any help/suggestions will be highly appreciated.
library(data.table)
library(foreign)
library(readstata13)
library(rgdal)
library(maptools)
library(ggplot2)
library(dplyr)
load(url("
https://github.com/valentinitnelav/RandomScripts/blob/master/NaturalEarth.RData?raw=true
"))
PROJ <- "+proj=robin +lon_0=0 +x_0=0 +y_0=0 +ellps=WGS84 +datum=WGS84
+units=m +no_defs"
NE_countries_rob <- spTransform(NE_countries, CRSobj = PROJ)
NE_graticules_rob <- spTransform(NE_graticules, CRSobj = PROJ)
NE_box_rob <- spTransform(NE_box, CRSobj = PROJ)
# project long-lat coordinates for graticule label data frames
# (two extra columns with projected XY are created)
prj.coord <- project(cbind(lbl.Y$lon, lbl.Y$lat), proj=PROJ)
lbl.Y.prj <- cbind(prj.coord, lbl.Y)
names(lbl.Y.prj)[1:2] <- c("X.prj","Y.prj")
prj.coord <- project(cbind(lbl.X$lon, lbl.X$lat), proj=PROJ)
lbl.X.prj <- cbind(prj.coord, lbl.X)
names(lbl.X.prj)[1:2] <- c("X.prj","Y.prj")
m <- ggplot() +
# add Natural Earth countries projected to Robinson, give black border
and fill with gray
geom_polygon(data=NE_countries_rob, aes(long,lat, group=group),
colour="black", fill="gray80", size = 0.25) +
# Note: "Regions defined for each Polygons" warning has to do with
fortify transformation. Might get deprecated in future!
# alternatively, use use map_data(NE_countries) to transform to data
frame and then use project() to change to desired projection.
# add Natural Earth box projected to Robinson
geom_polygon(data=NE_box_rob, aes(x=long, y=lat), colour="black",
fill="transparent", size = 0.25) +
# add graticules projected to Robinson
geom_path(data=NE_graticules_rob, aes(long, lat, group=group),
linetype="dotted", color="grey50", size = 0.25) +
# add graticule labels - latitude and longitude
geom_text(data = lbl.Y.prj, aes(x = X.prj, y = Y.prj, label = lbl),
color="grey50", size=2) +
geom_text(data = lbl.X.prj, aes(x = X.prj, y = Y.prj, label = lbl),
color="grey50", size=2) +
# the default, ratio = 1 in coord_fixed ensures that one unit on the
x-axis is the same length as one unit on the y-axis
coord_fixed(ratio = 1) +
geom_point(data=df,
aes(x=lon, y=lat), colour="Deep Pink",
fill="Pink",pch=21, size=2, alpha=I(0.7))
# remove the background and default gridlines
theme_void()
## coordinates dataframe
dput(df)
structure(list(lon = c(2.67569724621467, 17.5766416259819,
28.4126232192772,
23.8147674538232, 29.8917589327105), lat = c(28.1503115976162,
-12.3388787380201, 9.78891068739477, -22.1873831176644, -3.36546931479253
)), class = "data.frame", row.names = c(NA, -5L))
Sincerely,
Milu
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--
Roger Bivand
Department of Economics, Norwegian School of Economics,
Helleveien 30, N-5045 Bergen, Norway.
voice: +47 55 95 93 55; e-mail: roger.biv...@nhh.no
https://orcid.org/0000-0003-2392-6140
https://scholar.google.no/citations?user=AWeghB0AAAAJ&hl=en
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