R and ggplot2: how to connect points for a line chart and polar coordinates?

Question

As my colleague points out, connecting dots is what they learn at the expat school.

Here are the data:

hour_timetable mean_delayed_pass 0 6.074 1 6.512 2 7.632 3 9.393 4 8.759 5 4.600 6 6.040 7 5.575 8 5.680 9 6.315 10 6.895 11 7.852 12 6.832 13 6.961 14 6.322 15 5.954 16 5.579 17 5.540 18 5.142 19 5.579 20 6.139 21 6.501 22 6.140 23 6.061 

and here is the code:

 library(ggplot2) ggplot(data = test_vis, aes(x = factor(hour_timetable), y = mean_delayed_pass, group = 1)) + ylim(0, NA) + geom_point(color = 'purple', stat = 'identity') + geom_line(color = 'purple') + coord_polar(start = -0.12) # why offset? 

Answer 1

Use geom_polygon() instead of geom_line() . You can set an empty fill for the polygon using geom_polygon(..., fill=NA) .

Try the following:

 library(ggplot2) ggplot(data = test_vis, aes(x = factor(hour_timetable), y = mean_delayed_pass, group = 1)) + ylim(0, NA) + geom_point(color = 'purple', stat = 'identity') + geom_polygon(color = 'purple', fill=NA) + coord_polar(start = - pi * 1/24) 

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To set a zero point at the top of the graph, use offset = - pi / 24 .