CODEWITHSUNDEEP
rggplot2
Schillerlocke
Schillerlocke

Reputation: 343

ggplot manually change axis scale order for time variable of 24 hours

I want to change the order in which the x-axis labels are displayed. Below is my sample data and my graph. You can see, that the 23:30 mark is on the far right. The x-axis should start by 23:30 on the left, so that all the bars are nicely condensed.

DF <- data.frame(time = as.POSIXct(c("1970-01-01 23:30:00", "1970-01-01 23:30:00", "1970-01-01 23:30:00", "1970-01-01 00:00:00", "1970-01-01 00:00:00",
                                     "1970-01-01 00:30:00", "1970-01-01 00:30:00", "1970-01-01 01:00:00", "1970-01-01 01:30:00", "1970-01-01 01:30:00")))

library(ggplot2)
ggplot(data = DF) +
  geom_bar(aes(x = time))+
  scale_x_datetime(date_breaks = "30 min", date_labels = "%H:%M")+
  theme(axis.text.x = element_text(angle = 90, vjust = 0.5, hjust=1))

I tried to add something like limits = (c(as.POSIXct(min("1970-01-01 23:30"), max("1970-01-01 10:00")))) but it just give me error messages:

Removed 7 rows containing non-finite values (stat_count)

1: In strptime(xx, f, tz = tz) : unknown timezone '1970-01-01 10:00'

2: In as.POSIXct.POSIXlt(x) : unknown timezone '1970-01-01 10:00'

I'd be really glad about some help!

Upvotes: 1

Views: 353

Answers (1)

Georgery
Georgery

Reputation: 8117

Does this help?

DF %>%
    mutate(time = if_else(hour(time) > 4, time - days(1), time)) %>%
    ggplot(aes(time)) +
    geom_bar() + 
    scale_x_datetime(date_breaks = "30 min", date_labels = "%H:%M")+
    theme(axis.text.x = element_text(angle = 90, vjust = 0.5, hjust=1))

enter image description here

The point is that 23:30 is after 01:00 and therefore should be on the right. If you want these times to be on the left, you need to change the date (virtually) if the time is after some cut-off point. The date_labels argument only changes what is displayed on the axis.

Upvotes: 3

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