I am trying to create a plot of user login behavior for a two month period. I used the qplot function from the ggplot2 package, and with the following code
qplot(date_time, login_count, data=client_login_clean)
I plotted login_count over time as shown below. Unfortunately, the y-axis, num_records is sorted such that the first five tick marks on the y-axis are 1, 10, 106, 11, and 12, rather than 1, 2, 3, 4, 5. Could someone let me know how to fix this?
That's because, for some reason, your login_count variable is a character vector. ggplot internally coerces all character vectors to factors, with labels ordered alphabetically, and then sorts the axis according to that order.
I also think I know why this happened: "num_records" is actually a value in your login_count column, so the whole thing has been coerced to a character vector. Delete that element and use as.numeric, then the ordering should be correct. This is a good opportunity to read over your data loading/generating process and make sure you haven't made any other mistakes. Sometimes the tiniest bugs can uncover massive problems you would never have noticed otherwise.
As a side note, this is why you should be careful with character-class variables and ggplot plotting. You can save yourself a lot of headaches by explicitly specifying a factor ordering up front.
You almost certainly have your variable encoded as a factor rather than an integer. Try login_count <- as.numeric( as.character( login_count ) ) then run it again. An alternative is taRifx::destring.
As a side note, a wizard never mis-sorts his axis. He sorts it precisely as he means to.
