Q:

R join coordinates on map with lines

I have a list of start longidudes,latitudes and end longitudes and latitudes in a .csv file which i need to plot on a map and join with lines. The coordinates are for Manchester in England.
.csv example:
Timestamp    Start Description  End Description  Start(lon,lat)      End(lon,lat)
24/10/2016       Wimslow          Simonsway      53.371535,-2.23148   53.32803,-2.246991 
14/10/2016     Horwich Park       M1 3BG         53.58194,-2.53801    53.47837,-2.23296  

etc.

A:

Assuming your data is called dat you can first create seperate columns for Lon and Lat (careful, the values are in opposite order of the variable names), then use geom_segment to plot the lines.
library(tidyr)
library(ggmap)
library(ggplot2)

map <- get_map(location = 'Manchester', zoom = 9, scale = 2)
dat <- dat %>%
  separate(Start.lon.lat., c("Start.Lat", "Start.Lon"), sep =",") %>%
  separate(End.lon.lat., c("End.Lat", "End.Lon"), sep =",")

ggmap(map) +
  geom_segment(data = dat, aes(x = as.numeric(Start.Lon), 
                               y = as.numeric(Start.Lat), 
                               xend = as.numeric(End.Lon), 
                               yend = as.numeric(End.Lat)))

