I’m currently trying to display my data on a map as points. In fact I got two different data sets of two different studies which I’d like to combine on the map. But my first problem was where to find a map to use for my purpose.
#In the R graphics Cookbook I read about this code to create a map using the ggplot2 package
library(ggplot2)
library(maps)
states_map <- mapd_data(“state”)
ggplot(states_map, aes(x=long, y=lat, group=group)) +
geom_polygon(fill=”white”, colour=”black”) +
#Then I added the data of my two data sets and it worked perfectly fine.
geom_point(data = dat1, aes(x = longitude, y = latitude, group= NA), shape=21, col = "black", fill=”red”, size = dat1$var1) +
geom_point(data = dat2, aes(x = longitude, y = latitude, group= NA), shape=21, col = "black", fill=”blue”, size = dat2$var2)
Now I want to add two legends, one to explain the difference between the point colors and the other to explain the point size. Both data sets can share the same legend for the point size because Var1 and Var2 are on the same scale. But I don’t know how to add custom legends to a ggplot (I even don’t achieve to add any legend to the ggplot). It would be nice to have anything like legend()-function which adds a legend to a normal plot, but I think ggplot wasn’t programmed to solve problems like this on your own. Another approach to solve the problem could be to plot the map without using ggplot.
If you want a legend then you have to map on an aesthetic, i.e. move fill=... and size=... inside aes(). After doing so you could set your desired fill colors via scale_fill_manual:
library(ggplot2)
library(maps)
states_map <- map_data("state")
dat1 <- data.frame(longitude = -110, latitude = 35, var1 = 100)
dat2 <- data.frame(longitude = -90, latitude = 40, var2 = 200)
ggplot(states_map, aes(x=long, y=lat)) +
geom_polygon(aes(group=group), fill="white", colour="black") +
geom_point(data = dat1, aes(x = longitude, y = latitude, fill = "dat1", size = var1), shape=21, col = "black") +
geom_point(data = dat2, aes(x = longitude, y = latitude, fill = "dat2", size = var2), shape=21, col = "black") +
scale_fill_manual(values = c(dat1 = "red", dat2 ="blue"), labels = c(dat1 = "Data 1", dat2 ="Data 2"))
Related
I am trying to label my polygons by using ggplot in R. I found a topic here on stackoverflow that I think is very close to what I want except with points.
Label points in geom_point
I found some methods online. Now I first need to find the central location of each shape and then I have to put these locations together with the name together. Then link this to the labeling function in geom_text()
ggplot centered names on a map
Since I have been trying for a long time now I decided to ask the question and hope that someone here can give me the final push to what I want. My plotting function:
region_of_interest.fort <- fortify(region_of_interest, region = "score")
region_of_interest.fort$id <- as.numeric(region_of_interest.fort$id)
region_of_interest.fort$id <- region_of_interest.fort$id
region_of_interest.fort1 <- fortify(region_of_interest, region = "GM_NAAM")
region_of_interest.fort1$id <- as.character(region_of_interest.fort1$id)
region_of_interest.fort1$id <- region_of_interest.fort1$id
idList <- unique(region_of_interest.fort1$id)
centroids.df <- as.data.frame(coordinates(region_of_interest))
names(centroids.df) <- c("Longitude", "Latitude")
randomMap.df <- data.frame(id = idList, shading = runif(length(idList)), centroids.df)
ggplot(data = region_of_interest.fort, aes(x = long, y = lat, fill = id, group = group)) +
geom_polygon() +
geom_text(centroids.df, aes(label = id, x = Longitude, y = Latitude)) +
scale_fill_gradient(high = "green", low = "red", guide = "colorbar") +
coord_equal() +
theme() +
ggtitle("Title")
It gives me the error: ggplot2 doesn't know how to deal with data of class uneval
My data
region_of_interest$GM_NAAM
[1] Groningen Haren Ooststellingwerf Assen Aa en Hunze Borger- Odoorn
[7] Noordenveld Westerveld Tynaarlo Midden-Drenthe
415 Levels: 's-Gravenhage 's-Hertogenbosch Aa en Hunze Aalburg Aalsmeer Aalten ... Zwolle
region_of_interest$score
[1] 10 -2 -1 2 -1 -4 -4 -5 0 0
Try something like this?
Get a data frame of the centroids of your polygons from the
original map object.
In the data frame you are plotting, ensure there are columns for
the ID you want to label, and the longitude and latitude of those
centroids.
Use geom_text in ggplot to add the labels.
Based on this example I read a world map, extracting the ISO3 IDs to use as my polygon labels, and make a data frame of countries' ID, population, and longitude and latitude of centroids. I then plot the population data on a world map and add labels at the centroids.
library(rgdal) # used to read world map data
library(rgeos) # to fortify without needing gpclib
library(maptools)
library(ggplot2)
library(scales) # for formatting ggplot scales with commas
# Data from http://thematicmapping.org/downloads/world_borders.php.
# Direct link: http://thematicmapping.org/downloads/TM_WORLD_BORDERS_SIMPL-0.3.zip
# Unpack and put the files in a dir 'data'
worldMap <- readOGR(dsn="data", layer="TM_WORLD_BORDERS_SIMPL-0.3")
# Change "data" to your path in the above!
worldMap.fort <- fortify(world.map, region = "ISO3")
# Fortifying a map makes the data frame ggplot uses to draw the map outlines.
# "region" or "id" identifies those polygons, and links them to your data.
# Look at head(worldMap#data) to see other choices for id.
# Your data frame needs a column with matching ids to set as the map_id aesthetic in ggplot.
idList <- worldMap#data$ISO3
# "coordinates" extracts centroids of the polygons, in the order listed at worldMap#data
centroids.df <- as.data.frame(coordinates(worldMap))
names(centroids.df) <- c("Longitude", "Latitude") #more sensible column names
# This shapefile contained population data, let's plot it.
popList <- worldMap#data$POP2005
pop.df <- data.frame(id = idList, population = popList, centroids.df)
ggplot(pop.df, aes(map_id = id)) + #"id" is col in your df, not in the map object
geom_map(aes(fill = population), colour= "grey", map = worldMap.fort) +
expand_limits(x = worldMap.fort$long, y = worldMap.fort$lat) +
scale_fill_gradient(high = "red", low = "white", guide = "colorbar", labels = comma) +
geom_text(aes(label = id, x = Longitude, y = Latitude)) + #add labels at centroids
coord_equal(xlim = c(-90,-30), ylim = c(-60, 20)) + #let's view South America
labs(x = "Longitude", y = "Latitude", title = "World Population") +
theme_bw()
Minor technical note: actually coordinates in the sp package doesn't quite find the centroid, but it should usually give a sensible location for a label. Use gCentroid in the rgeos package if you want to label at the true centroid in more complex situations like non-contiguous shapes.
The accepted answer here may work, but the actual question asked specifically notes that there is an error "ggplot2 doesn't know how to deal with data of class uneval."
The reason that it is giving you the error is because the inclusion of centroids.df needs to be a named variable (e.g. accompanied by "data=")
Currently:
ggplot(data = region_of_interest.fort, aes(x = long, y = lat, fill = id, group = group)) +
geom_polygon() +
geom_text(centroids.df, aes(label = id, x = Longitude, y = Latitude)) +
scale_fill_gradient(high = "green", low = "red", guide = "colorbar") +
coord_equal() +
theme() +
ggtitle("Title")
Should be (note: "data=centroids.df"):
ggplot(data = region_of_interest.fort, aes(x = long, y = lat, fill = id, group = group)) +
geom_polygon() +
geom_text(data=centroids.df, aes(label = id, x = Longitude, y = Latitude)) +
scale_fill_gradient(high = "green", low = "red", guide = "colorbar") +
coord_equal() +
theme() +
ggtitle("Title")
This issue was addressed here: How to deal with "data of class uneval" error from ggplot2?
I have the following:
set.seed(100)
df <- data.frame(
lng = runif(n=20, min=5, max=10),
lat = runif(n=20, min=40, max=50),
year = rep(c("2001","2002","2003","2004"), each=5),
season = sample(c("spring", "autumn"), 10, replace = T),
info = sample(c("yes","no"), 10, replace = T)
)
Which can be plotted by:
ggplot() +
geom_point(data=df,
aes(x = lng,
y = lat,
color = year,
shape = season),
size=3)
To produce:
Great. But I want a red outline on the shapes were info == "yes".
The desired output would be:
Not made using actual data, just for demonstrative purpose. Made in powerpoint.
Admittedly it is similar to this question here, but not quite.
I am happy to split the df using a filter if easier then two + geom_points()
Many thanks
Jim
Below is a quick solution (not the best), which is to use another scale, and below I use size as the scale, then use guides() to manually specify the shape to appear in the legend. you need to plot the bigger red shapes first and then plot over so that it looks like an outline:
ggplot() +
geom_point(data=subset(df,info=="yes"),
aes(x=lng,y=lat,shape = season,size=info),col="red") +
scale_size_manual(values=3.6)+
geom_point(data=df,
aes(x = lng,
y = lat,
color = year,
shape = season),
size=3)+
guides(size = guide_legend(override.aes = list(shape = 1)))
You can change the legend for the shape by playing around with options in the guide()
As I know gganimate has been in version 1.0.3,we can use transition_* function to plot a dynamic graph. But when I run following code ,there is an error :
Error in `$<-.data.frame`(`*tmp*`, "group", value = "") :
replacement has 1 row, data has 0
code:
library(ggmap)
library(gganimate)
world <- map_data("world")
world <- world[world$region!="Antarctica",]
data <- data.frame(state = c("Alabama","Alaska","Alberta","Alberta","Arizona"),
lon = c(-86.55,-149.52,-114.05,-113.25,-112.05),
lat = c(33.30,61.13,51.05,53.34,33.30)
)
ggplot()+
geom_map(data = world,
map = world,
aes(long,lat,map_id = region),
color = '#333300',
fill = '#663300') +
geom_point(data = data,
aes(x = lon, y = lat),
size = 2.5) +
geom_jitter(width = 0.1) +
transition_states(states = state)
You have no data defined in the top level ggplot() line, so state in transition_* comes out of nowhere.
It's also unclear to me why you have a geom_jitter level in your code. Like transition_*, it has no top level data / aesthetic mappings to inherit, so it would have thrown an error too, had transition_* not triggered an error first. In addition, even if we add the mappings, given the range of lat/lon coordinates in your data, jittering by 0.1 is hardly going to matter visually.
You can try the following:
# put data in top level ggplot()
ggplot(data,
aes(x = lon, y = lat))+
geom_map(data = world,
map = world,
aes(long,lat,map_id = region),
color = '#333300', fill = '#663300',
# lighter background for better visibility
alpha = 0.5) +
geom_point(size = 2.5) +
# limit coordinates to relevant range
coord_quickmap(x = c(-180, -50), y = c(25, 85)) +
transition_states(states = state)
I'm trying to highlight zones on a map based on an associated factor, like so:
My initial problem was that, because the boundaries are overlapping, the zones would display improperly, like this:
I fixed that by hackily subsetting the data, which resulted in the first picture.
#First Map With No Legend
p <- ggplot() +
geom_polygon(data = OpportunityAreas.df[OpportunityAreas.df$Opp_Area == 'Yes',],
aes(long,lat,group=group), fill = "#d2eef7", color = 'black') +
geom_polygon(data = OpportunityAreas.df[OpportunityAreas.df$Opp_Area == 'No',],
aes(long,lat,group=group), fill = "#d2eef7", color = 'orange') +
coord_map()
But now I have no legend and also it just seems like a poor solution. Is there a proper way to color polygon boundaries by an associated factor?
#Second Map With Improper Boundaries
p.improperly.drawn <- ggplot() +
geom_polygon(data = OpportunityAreas.df,
aes(long,lat,group=group, color = Opp_Area), fill = "#d2eef7") +
coord_map()
Your first solution needs only a small tweak to get what you are looking for: move the color arguments within the geom_polygon calls to a mapping = aes() call instead. For the first call, mapping = aes(color = 'black') and for the second geom_polygon call use mapping = aes(color = 'orange').
I do not have access to the OpportunityAreas.df in your example so I will use some generic mapping data for my example below.
library(ggplot2)
library(mapdata)
counties <- map_data("county")
ca_county <- subset(counties, region == "california")
ca_county$color <- cut(ca_county$group, 2, labels = c("A", "B"))
ggplot() +
aes(x = long, y = lat, group = group) +
geom_polygon(data = subset(ca_county, color == "A"),
mapping = aes(color = "A"),
fill = NA) +
geom_polygon(data = subset(ca_county, color == "B"),
mapping = aes(color = "B"),
fill = NA)
I am trying to label my polygons by using ggplot in R. I found a topic here on stackoverflow that I think is very close to what I want except with points.
Label points in geom_point
I found some methods online. Now I first need to find the central location of each shape and then I have to put these locations together with the name together. Then link this to the labeling function in geom_text()
ggplot centered names on a map
Since I have been trying for a long time now I decided to ask the question and hope that someone here can give me the final push to what I want. My plotting function:
region_of_interest.fort <- fortify(region_of_interest, region = "score")
region_of_interest.fort$id <- as.numeric(region_of_interest.fort$id)
region_of_interest.fort$id <- region_of_interest.fort$id
region_of_interest.fort1 <- fortify(region_of_interest, region = "GM_NAAM")
region_of_interest.fort1$id <- as.character(region_of_interest.fort1$id)
region_of_interest.fort1$id <- region_of_interest.fort1$id
idList <- unique(region_of_interest.fort1$id)
centroids.df <- as.data.frame(coordinates(region_of_interest))
names(centroids.df) <- c("Longitude", "Latitude")
randomMap.df <- data.frame(id = idList, shading = runif(length(idList)), centroids.df)
ggplot(data = region_of_interest.fort, aes(x = long, y = lat, fill = id, group = group)) +
geom_polygon() +
geom_text(centroids.df, aes(label = id, x = Longitude, y = Latitude)) +
scale_fill_gradient(high = "green", low = "red", guide = "colorbar") +
coord_equal() +
theme() +
ggtitle("Title")
It gives me the error: ggplot2 doesn't know how to deal with data of class uneval
My data
region_of_interest$GM_NAAM
[1] Groningen Haren Ooststellingwerf Assen Aa en Hunze Borger- Odoorn
[7] Noordenveld Westerveld Tynaarlo Midden-Drenthe
415 Levels: 's-Gravenhage 's-Hertogenbosch Aa en Hunze Aalburg Aalsmeer Aalten ... Zwolle
region_of_interest$score
[1] 10 -2 -1 2 -1 -4 -4 -5 0 0
Try something like this?
Get a data frame of the centroids of your polygons from the
original map object.
In the data frame you are plotting, ensure there are columns for
the ID you want to label, and the longitude and latitude of those
centroids.
Use geom_text in ggplot to add the labels.
Based on this example I read a world map, extracting the ISO3 IDs to use as my polygon labels, and make a data frame of countries' ID, population, and longitude and latitude of centroids. I then plot the population data on a world map and add labels at the centroids.
library(rgdal) # used to read world map data
library(rgeos) # to fortify without needing gpclib
library(maptools)
library(ggplot2)
library(scales) # for formatting ggplot scales with commas
# Data from http://thematicmapping.org/downloads/world_borders.php.
# Direct link: http://thematicmapping.org/downloads/TM_WORLD_BORDERS_SIMPL-0.3.zip
# Unpack and put the files in a dir 'data'
worldMap <- readOGR(dsn="data", layer="TM_WORLD_BORDERS_SIMPL-0.3")
# Change "data" to your path in the above!
worldMap.fort <- fortify(world.map, region = "ISO3")
# Fortifying a map makes the data frame ggplot uses to draw the map outlines.
# "region" or "id" identifies those polygons, and links them to your data.
# Look at head(worldMap#data) to see other choices for id.
# Your data frame needs a column with matching ids to set as the map_id aesthetic in ggplot.
idList <- worldMap#data$ISO3
# "coordinates" extracts centroids of the polygons, in the order listed at worldMap#data
centroids.df <- as.data.frame(coordinates(worldMap))
names(centroids.df) <- c("Longitude", "Latitude") #more sensible column names
# This shapefile contained population data, let's plot it.
popList <- worldMap#data$POP2005
pop.df <- data.frame(id = idList, population = popList, centroids.df)
ggplot(pop.df, aes(map_id = id)) + #"id" is col in your df, not in the map object
geom_map(aes(fill = population), colour= "grey", map = worldMap.fort) +
expand_limits(x = worldMap.fort$long, y = worldMap.fort$lat) +
scale_fill_gradient(high = "red", low = "white", guide = "colorbar", labels = comma) +
geom_text(aes(label = id, x = Longitude, y = Latitude)) + #add labels at centroids
coord_equal(xlim = c(-90,-30), ylim = c(-60, 20)) + #let's view South America
labs(x = "Longitude", y = "Latitude", title = "World Population") +
theme_bw()
Minor technical note: actually coordinates in the sp package doesn't quite find the centroid, but it should usually give a sensible location for a label. Use gCentroid in the rgeos package if you want to label at the true centroid in more complex situations like non-contiguous shapes.
The accepted answer here may work, but the actual question asked specifically notes that there is an error "ggplot2 doesn't know how to deal with data of class uneval."
The reason that it is giving you the error is because the inclusion of centroids.df needs to be a named variable (e.g. accompanied by "data=")
Currently:
ggplot(data = region_of_interest.fort, aes(x = long, y = lat, fill = id, group = group)) +
geom_polygon() +
geom_text(centroids.df, aes(label = id, x = Longitude, y = Latitude)) +
scale_fill_gradient(high = "green", low = "red", guide = "colorbar") +
coord_equal() +
theme() +
ggtitle("Title")
Should be (note: "data=centroids.df"):
ggplot(data = region_of_interest.fort, aes(x = long, y = lat, fill = id, group = group)) +
geom_polygon() +
geom_text(data=centroids.df, aes(label = id, x = Longitude, y = Latitude)) +
scale_fill_gradient(high = "green", low = "red", guide = "colorbar") +
coord_equal() +
theme() +
ggtitle("Title")
This issue was addressed here: How to deal with "data of class uneval" error from ggplot2?