0

My objective is to portray the locations with varying numbers of traffic conflicts in a road intersection. My data consists of all the conflicts that we observed in a given time period at an intersection coded into a .CSV file with the following fields "time of conflict", "TTC" (means Time to Collision), "Lat", "Lon" and "Conflict Type". I figured the best way to do so would be using the 'ggmap+stat_density2d' function in R. I am using the following code:

df = read.csv(filename, header = TRUE)
int.map = get_map(location = c(mean.long, mean.lat), zoom = 20, maptype = "satellite")
int.map = ggmap(int.map, extent ="device", legend = "right")'''
int.map +stat_density2d(data = new_xdf, aes(x, y, fill = ..levels.., alpha = ..levels..),
                                 geom = "polygon")
int.map + scale_fill_gradientn(guide = "colourbar", colours = rev(brewer.pal(7,"Spectral")),
                                         name = "Conflict Density")

The output is a very nice map Safety Heat Map that correctly portrays the conflict hotspots. My problem is that in the legends it gives the values of "levels" automatically calculated by the 'stat_density2d()' function. I tried searching for a way to display, say, the counts of all conflict points inside each level on the legend bar but to no avail.

I did find the below link that handles a similar question, but the problem with that is that it creates a new data frame (new_xdf) with much more points than in the original data. Thus, the counts determined in that program seems to be of no use to me as I want the exact number of conflict points in my original data to be displayed in the legends bar.

How to find points within contours in R?

Thanks in advance.

Edit: Link to a sample data file

https://docs.google.com/spreadsheets/d/11vc3lOhzQ-tgEiAXe-MNw2v3fsAqnadweVrvBdNyNuo/edit?usp=sharing

0 Answers0