Reverse datetime (POSIXct data) axis in ggplot previous solution broken-CodePudding

A previous post detailed a solution to reversing the time on a ggplot post with this data:

MyData <-
  structure(list(Date = structure(c(1492979809.99827, 1492602845.68722, 
  1493093428.90318, 1492605578.0691, 1492961342.65056, 1492771976.83545, 
  1493020588.88485, 1493057018.85104, 1492852011.23873, 1492855996.55059
  ), class = c("POSIXct", "POSIXt")), Value = c(4.52885504579172, 
  6.0024610790424, 8.96430060034618, 7.06435370026156, 5.08460514713079, 
  3.47828012891114, 6.29844291834161, 0.898315710946918, 1.44857675535604, 
  5.74641009094194)), .Names = c("Date", "Value"), row.names = c(NA, 
  -10L), class = "data.frame")

and this solution:

c_trans <- function(a, b, breaks = b$breaks, format = b$format) {
  a <- as.trans(a)
  b <- as.trans(b)

  name <- paste(a$name, b$name, sep = "-")

  trans <- function(x) a$trans(b$trans(x))
  inv <- function(x) b$inverse(a$inverse(x))

  trans_new(name, trans, inverse = inv, breaks = breaks, format=format)

}

rev_date <- c_trans("reverse", "time")

ggplot(MyData, aes(x=Value, y=Date))  
  geom_point()   
  scale_y_continuous(trans = rev_date)

However, when I try and run this code now I get the following error: Error: Invalid input: time_trans works with objects of class POSIXct only

I am running this code on R version 4.2.2 and cannot find a solution to fix this.

I tried forcing my data into POSIXct format, but the graphing still breaks in the same way.

CodePudding user response：

You could slightly modify the function coord_x_datetime from the tidyquant package to reverse the datetime for your y-axis. Here is the function called coord_y_datetime:

coord_y_datetime <- function(xlim = NULL, ylim = NULL, expand = TRUE) {
  if (!is.null(ylim)) {
    ylim <- lubridate::as_datetime(ylim)
  }
  ggplot2::coord_cartesian(xlim = xlim, ylim = ylim, expand = expand)
}

Here is a reproducible example:

library(ggplot2)
ggplot(MyData, aes(x = Value, y = Date))  
  geom_point()   
  coord_y_datetime(ylim = c(max(MyData$Date), min(MyData$Date)))

^{Created on 2022-11-14 with reprex v2.0.2}