Points resize on ggplot geom_point and no legend?
So here is my code for the basemap:
gg <- ggmap(Peru) +
geom_map(data = peru.coast, map = peru.coast, aes(x = long, y = lat, map_id = region),
fill="gray", color="black") +
xlim(-86, -70) +
ylim(-20, -4) +
labs(x = "Longitude", y = "Latitude") +
coord_map()
Then I add to the cities I want to name manually (not sure how to do this using google maps as I only wanted 4 of them)
gg <- gg + geom_point(aes(x=-78.981885, y=-8.229354, size=3)) +
annotate("text", label='Salaverry', size=4, x=-77.2, y=-8.229354) +
geom_point(aes(x=-71.345838, y=-17.644347, size=3)) +
annotate("text", x=-70.545838, y=-17.644347, label = 'Ilo', size=4) +
geom_point(aes(x=-77.142375, y=-12.047544, size=3)) +
annotate("text", x=-75.9, y=-12.047544, label = 'Callao', size=4) +
geom_point(aes(x=-78.610677, y=-9.074166, size=3)) +
annotate("text", x=-76.9, y=-9.074166, label = 'Chimbote', size=4)
gg <- gg + guides(size=FALSE) #this removes the legend with the black dot and '3' on it
gg
I get this lovely map:
Then I use this dataset to add datapoints and I want to make the points larger or smaller according to the 'n' abundance
Trip_Set sex Set.Lon Set.Lat n
119_1 hembra -81.09390 -9.32338 2
119_7 hembra -81.03117 -9.09622 1
161_3 macho -83.76533 -9.74533 5
193_8 hembra -81.00888 -9.00950 7
255_5 macho -80.14992 -8.64592 1
271_6 hembra -72.20233 -18.05117 6
271_6 macho -72.20233 -18.05117 7
328_7 hembra -78.66667 -12.91700 2
403_3 hembra -80.03037 -10.03900 1
428_2 hembra -83.01305 -8.74883 2
655_4 hembra -71.58363 -18.24882 1
using this code:
ggAB <- gg + geom_point(data=dframe4, aes(Set.Lon, Set.Lat, colour='red', size=n))
ggAB <- ggAB + theme(legend.title = element_text(colour="black", size=12, face="bold"))
ggAB <- ggAB + guides(colour=FALSE) #This removes the legend for the red colour
ggAB <- ggAB + scale_size(name='Sharks per line', range = c(5,9))
ggAB <- ggAB + theme(legend.key=element_rect(fill = NA)) #This removes the boxes around the points
ggAB
However, when I do this, I get this:
The datapoints are plotted fine (ugh!), But why does that make the dots bigger for my city names? I can't get it to just keep an abundance of its "n" datapoints ... It also doesn't include the automatic legend (as ggplot usually does), even when I try to manually use its scale_discrete function.
I thought it might have something to do with the fact that I am using gg + guides(size=FALSE)
in the first part, but even when you accept it it doesn't work but adds datapoints to the annoying legend for my city.
Any ideas?
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The problem is that in the code where you add the cities you have placed size
inside aes
. Therefore, it is also converted when called scale_size(name='Sharks per line', range = c(5,9))
. Just use size
outside aes
:
gg <- gg + geom_point(aes(x=-78.981885, y=-8.229354), size=3) +
annotate("text", label='Salaverry', size=4, x=-77.2, y=-8.229354) +
geom_point(aes(x=-71.345838, y=-17.644347), size=3) +
annotate("text", x=-70.545838, y=-17.644347, label = 'Ilo', size=4) +
geom_point(aes(x=-77.142375, y=-12.047544), size=3) +
annotate("text", x=-75.9, y=-12.047544, label = 'Callao', size=4) +
geom_point(aes(x=-78.610677, y=-9.074166), size=3) +
annotate("text", x=-76.9, y=-9.074166, label = 'Chimbote', size=4)
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In addition to @ shadow's answer, I would like to leave the following for the OP as additional information. This comes from a chat with the OP. If you want to avoid using annotate
, you can use geocode
in package ggmap
. Here I have added some of my answer to the OP's previous question, and I have merged / modified the OP's code. One change is that I usedalpha
so you can see red / pink dots in the ocean. It should be noted that the positions of city names are not ideal; the further you go south on the map, the more you can see the gaps between points and city names. It might have something to do with the map projection. According to the Wiki, googlemap uses something close to a marker, but not the same. This could be the reason. Some GIS experts can provide additional information here.
library(ggmap)
library(mapdata)
library(ggplot2)
# Get Peru map
Peru <- get_map(location = "Peru", zoom = 5, maptype="satellite")
# This is the layer I wish to put over the top
coast_map <- fortify(map("worldHires", fill = TRUE, plot = FALSE))
# Subset data for Peru
peru.coast <- subset(coast_map, region == "Peru")
### Get lon and lat using geocode() in the ggmap package and crate a data frame
cities <- c("Salaverry", "Chimbote", "Callao", "Ilo")
locations <- geocode(cities)
locations$city <- cities
locations2 <- transform(locations, lon2 = lon + 1.1) # This is for text position
ggmap(Peru) +
geom_map(data = peru.coast, map = peru.coast, aes(x = long, y = lat, map_id = region),
fill="gray", color="black") +
geom_point(data = locations2, aes(x = lon, y = lat, color = city), size = 4) +
geom_text(data = locations2, aes(x = lon2, y = lat, label = city), size = 3) +
scale_color_manual(values = rep(c("black"), times = 4)) +
geom_point(data = newdata, aes(Set.Lon, Set.Lat, size = n), colour = "red", alpha = 0.5) +
scale_size(name = "Sharks per line", range = c(5,9)) +
xlim(-86, -70) +
ylim(-20, -4) +
labs(x = "Longitude", y = "Latitude") +
coord_map("mercator") +
guides(colour=FALSE) +
theme(legend.key=element_rect(fill = NA))
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