R: scatter points using longitude/latitude - r

Question

I want to fill the colour on a map. However, the plot doesn't come out as aspected.
How can I visualize the data with longitude and latitude?
install.packages("WDI")
install.packages("tidyverse")
library(WDI)
library(tidyverse)
literacy_globe <- WDI(country = "all", indicator = "SE.ADT.LITR.ZS", start = 2015, end = 2018, extra = TRUE)
literacy_globe <- na.omit(literacy_globe)
ggplot(literacy_globe, aes(x = longitude, y = latitude, group = iso3c)) +
geom_point(aes(fill = income), colour = "white")
I'd like the result similar to:

Answer 1

You can use the following code
#Loading the required packges
library(WDI)
library(tidyverse)
library(maptools)
library("ggplot2")
library("sf")
#Downloading the data
literacy_globe <- WDI(country = "all", indicator = "SE.ADT.LITR.ZS", start = 2015, end = 2018, extra = TRUE)
#Removing the NAs
literacy_globe_1 <- na.omit(literacy_globe)
#Saving the data as .csv file as your data contains blank cells which are not NAs
write.csv(literacy_globe_1, "literacy_globe_1.csv")
#Reading the data from .csv file
data <- read.csv("literacy_globe_1.csv")
#Removing the NAs
literacy_globe <- na.omit(data)
summary(literacy_globe)
head(literacy_globe,2)
#Mapping using ggplot2 package
data(wrld_simpl)
#sp to sf conversion
world <- st_as_sf(wrld_simpl)
# now create the map
ggplot(world) +
geom_sf(colour = "black", fill = NA) + coord_sf(expand = FALSE) +
theme_bw() + geom_point(aes(longitude, latitude),data= literacy_globe, colour=alpha("red",0.7))
For white fill of polygon and grey outside area, you can use
ggplot(world) +
geom_sf(colour = "black", fill = "white") + coord_sf(expand = FALSE) +
geom_point(aes(longitude, latitude),data= literacy_globe, colour=alpha("red",0.7))
Update
choropleth map
literacy_globe <- WDI(country = "all", indicator = "SE.ADT.LITR.ZS", start = 2015, end = 2018, extra = TRUE)
literacy_globe <- na.omit(literacy_globe)
summary(literacy_globe)
head(literacy_globe,2)
#Using ggplot2 package
data(wrld_simpl)
#fortify shape file to get into dataframe
wrld_simpl.f <- fortify(wrld_simpl, region = "NAME")
class(wrld_simpl.f)
head(wrld_simpl.f)
#merge with coefficients and reorder
merge.shp<-merge(wrld_simpl.f,literacy_globe, by.x = "id", by.y = "country", all.x=TRUE)
final.plot<-merge.shp[order(merge.shp$order), ]
head(final.plot, 2)
#basic plot
ggplot() +
geom_polygon(data = final.plot,
aes(x = long, y = lat, group = group, fill = income),
color = "black", size = 0.25)

Answer 2

I found another way to draw the hierarchy scatter on world map, but i were not so sure if it has some drawbakcs.
literacy_globe <- WDI(country = "all", indicator = "SE.ADT.LITR.ZS", start =
2015, end = 2018, extra = TRUE)
literacy_globe <- na.omit(literacy_globe)
lit.long <- literacy_globe$longitude
lit.lat <- literacy_globe$latitude
income <- literacy_globe$income
# prepare a NULL map
mp<-NULL
mapworld<-borders("world",colour = "gray50",fill="white")
#mp = empty map
#plot a map
mp <- ggplot() + mapworld + ylim(-60,90)
#geom_point plot the data on it
mp2 <- mp + geom_point(aes(x = lit.long, y = lit.lat), color = "darkblue",
fill = income) +
scale_size(range = c(1,1))