Reputation: 73
I want to use R and ggmaps to plot a heatmap over a map of Mexico City,
I constructed a map with
g.map <- get_map(location = c(lon = -99.1393, lat = 19.3772),
zoom = 11, maptype = 'roadmap')
map <- ggmap(g.map)
I have a data frame of latitude / longitude and number of tweets in the area, like this
x y tweets
1 -99.300 19.200 1
2 -99.291 19.209 10
3 -99.282 19.218 2
4 -99.273 19.227 4
5 -99.264 19.236 5
6 -99.255 19.245 9
I can already plot a map with points representing each tweet, using
map + geom_point(aes(x=x,y=y,size=c,colour=c),data=tweets.df)
And I read on the other question that you could use geom_density2d
to plot a heatmap, but the results seem a bit odd
So, what am I doing wrong?
Upvotes: 3
Views: 1192
Reputation: 4999
You can try
map + geom_point(aes(x = x, y = y, size = c, colour = c),
data = tweets.df,
alpha = 0.5)
to get a cheap & easy heatmap effect.
Upvotes: 1