CODEWITHSUNDEEP
rggplot2
mikebmassey
mikebmassey

Reputation: 8594

Formatting dates on X axis in ggplot2

I'm having a very, very tough time getting the x-axis to look correct for my graphs.

Here is my data:

df <- data.frame(
  Month = factor(c(
    "2011-07-31", "2011-08-31", "2011-09-30", "2011-10-31", "2011-11-30",
    "2011-12-31", "2012-01-31", "2012-02-29", "2012-03-31", "2012-04-30",
    "2012-05-31", "2012-06-30"
  )),
  AvgVisits = c(
    6.98655104580674, 7.66045407330464, 7.69761337479304, 7.54387561322994,
    7.24483848458728, 6.32001400498928, 6.66794871794872, 7.207780853854,
    7.60281201431308, 6.70113837397123, 6.57634103019538, 6.75321935568936
  )
)

Here is the chart I am trying to graph:

ggplot(df, aes(x = Month, y = AvgVisits)) + 
  geom_bar() +
  theme_bw() +
  labs(x = "Month", y = "Average Visits per User")

That chart works fine - but, if I want to adjust the formatting of the date, I believe I should add this: scale_x_date(labels = date_format("%m-%Y"))

I'm trying to make it so the date labels are 'MMM-YYYY'

ggplot(df, aes(x = Month, y = AvgVisits)) + 
  geom_bar() +
  theme_bw() +
  labs(x = "Month", y = "Average Visits per User") +
  scale_x_date(labels = date_format("%m-%Y"))

When I plot that, I continue to get this error:

stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.

Despite hours of research on formatting of geom_line and geom_bar, I can't fix it. Can anyone explain what I'm doing wrong?

Edit: As a follow-up thought: Can you use date as a factor, or should you use as.Date on a date column?

Upvotes: 88

Views: 188344

Answers (2)

user5099519
user5099519

Reputation:

To show months as Jan 2017 Feb 2017 etc:

scale_x_date(date_breaks = "1 month", date_labels =  "%b %Y")

Angle the dates if they take up too much space:

theme(axis.text.x=element_text(angle=60, hjust=1))

Upvotes: 140

joran
joran

Reputation: 173697

Can you use date as a factor?

Yes, but you probably shouldn't.

...or should you use as.Date on a date column?

Yes.

Which leads us to this:

library(scales)
df$Month <- as.Date(df$Month)
ggplot(df, aes(x = Month, y = AvgVisits)) + 
  geom_bar(stat = "identity") +
  theme_bw() +
  labs(x = "Month", y = "Average Visits per User") +
  scale_x_date(labels = date_format("%m-%Y"))

enter image description here

in which I've added stat = "identity" to your geom_bar call.

In addition, the message about the binwidth wasn't an error. An error will actually say "Error" in it, and similarly a warning will always say "Warning" in it. Otherwise it's just a message.

Upvotes: 91

Related Questions