r - Order x axis day values in ggplot2

Question

I have below dataset. As you can see I have some quantitative for two weeks and Id like to make a comparison between their days ( i.e: Monday 09 with Monday 10 ):

      week       date       day     n
     (chr)     (date)     (chr) (int)
1  Week 09 2016-02-29    Monday  5535
2  Week 09 2016-03-01   Tuesday  7497
3  Week 09 2016-03-02 Wednesday  8658
4  Week 09 2016-03-03  Thursday  6113
5  Week 09 2016-03-04    Friday  4553
6  Week 09 2016-03-05  Saturday     2
7  Week 10 2016-03-07    Monday  5339
8  Week 10 2016-03-08   Tuesday  6196
9  Week 10 2016-03-09 Wednesday  5395
10 Week 10 2016-03-10  Thursday  5633

I got below code, but days are unordered.Is there anyway I can order these days in chronological order:

ggplot(data = my_data, aes(x = as.factor(x = day), 
                           y = n, 
                           col = week, 
                           group = week)) + 
  geom_line() + 
  geom_point()

Answer 1

You need to reorder the levels of the day, which is what determines plotting order. You can either type out the days of the week, or use your favorite method for generating a sequence of Sunday to Saturday dates and call weekdays (or format or strftime with format = %A) on it. You can either do this on your data.frame before you plot (a good idea, as that's the best way to store the data anyway), or inside of aes when you plot:

ggplot(data = my_data, aes(x = factor(day, weekdays(min(my_data$date) + 0:6)), 
                           y = n, 
                           col = week, 
                           group = week)) + 
    geom_line() + geom_point() + xlab('Weekday')