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.
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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