ggplot fails with duration objects.

[ghost]

Trying to print a ggplot object created using a tibble with a duration object inside yields the same error.

df <- tibble::tibble(                                                       
  a = 1:10,                                                                   
  b = lubridate::as.duration(1:10)                                            
)                                                                           
                                                                            
p <- ggplot2::ggplot(df, ggplot2::aes(x = a, y = b)) + ggplot2::geom_point()
p                                                                           
#> Error: Incompatible duration classes (Duration, integer). Please coerce with `as.duration`.

Initially, I thought this might be caused by the bug at r-lib/pillar#88, due to the same error message. Indeed, we encounter the same error message if df is printed, and this is caused by the pillar issue.

However, trying to print a ggplot object created using a data.frame with a duration object inside still yields the error, even though we're not using tibbles anymore.

df <- data.frame(                                                           
  a = 1:10,                                                                   
  b = lubridate::as.duration(1:10)                                            
)                                                                           
                                                                            
p <- ggplot2::ggplot(df, ggplot2::aes(x = a, y = b)) + ggplot2::geom_point()
p                                                                           
#> Error: Incompatible duration classes (Duration, integer). Please coerce with `as.duration`.

Given that ggplot2 depends on tibble, this is still likely caused by r-lib/pillar#88, even though we're not actually printing tibbles here. Perhaps the data.frame is being coerced to a tibble?

[ghost]

Curiously, the fix at r-lib/pillar/issues/88 did not resolve the above error messages.

Package versions:

• ggplot2_2.2.1
• tibble_1.4.2
• pillar_1.2.1

I don't know enough about the internals of ggplot2 to comment further on why this might be the case.

Edit: Upon further investigation, using period objects works:

df1 <- tibble::tibble(
  a = 1:10
  b = lubridate::seconds(1:10)
)

p <- ggplot2::ggplot(df1, ggplot2::aes(x = a, y = b)) + ggplot2::geom_point()
p

[dpseidel]

So this is genuine bug but I think it may be best solved in lubridate rather than ggplot2. All it would take is specifying a Compare method for duration and numeric objects, which currently doesn't exist and thus returns the above error. There may be a very good reason why this is not already specified but none seem immediately obvious to me.

Basically what is happening is ggplot2 is trying to check to make sure none of your data is outside the range/limits of the scale, but it's running into issues because duration objects don't maintain their class when range() is calculated. See below:

library(ggplot2)

df <- data.frame(                                                           
  a = 1:10,                                                                   
  b = lubridate::duration(1:10)                                            
)                                                                           

(x <- df$b)
#>  [1] "1s"  "2s"  "3s"  "4s"  "5s"  "6s"  "7s"  "8s"  "9s"  "10s"
class(x)
#> [1] "Duration"
#> attr(,"package")
#> [1] "lubridate"

(r <- range(df$b))
#> [1]  1 10
class(r)
#> [1] "numeric"

x < r[2]
#> Error: Incompatible duration classes (Duration, numeric). Please coerce with `as.duration`.

x < as.duration(r[2])
#> [1]  TRUE  TRUE  TRUE  TRUE  TRUE  TRUE  TRUE  TRUE  TRUE FALSE

For now, an easy way to get around this is to call the numeric .Data of your Duration object explicitly:

ggplot(df, aes(x = a, y = b@.Data)) + geom_point()

As you note, period objects don't have this problem because they do have a specified Compare method.

[dpseidel]

This is now fixed. The dev version of lubridate now includes a compare method for numeric and duration objects.

[lock]

This old issue has been automatically locked. If you believe you have found a related problem, please file a new issue (with reprex) and link to this issue. https://reprex.tidyverse.org/