reprex demo

reprex.R

#######################
####  Reprex demo  ####
#######################

## 2020-04-24

# A simple reprex --------------------------------------------------------------

dat <- data.frame(a = 1:2, b = LETTERS[1:2])
mean(dat$a)

## Copy the above and run reprex::reprex() -- markdown is now on my clipboard

# Can also provide code as an expression ---------------------------------------

reprex({
  dat <- data.frame(a = 1:2, b = LETTERS[1:2])
  mean(dat$a)
})

# Errors, warnings are included in output --------------------------------------

reprex({
  dat <- data.frame(a = 1:2, b = LETTERS[1:2])
  dat[, b]
})

# Everything you need should be included in the reprex -------------------------

library("ggplot2")
dat <- data.frame(a = 1:2, b = LETTERS[1:2])

reprex({
  p <- ggplot(dat, aes(x = a, y = b)) + geom_point()
})

# This will fail because ggplot2 is not loaded in the R session reprex creates
# Put library("ggplot2") and dat <- data.frame(a = 1:2, b = LETTERS[1:2]) 
# within the reprex

# Plots Just Work(TM) ----------------------------------------------------------

reprex({
  library("ggplot2")
  dat <- data.frame(a = 1:2, b = LETTERS[1:2])
  p <- ggplot(dat, aes(x = a, y = b)) + geom_point()
  p
})

# "But I need external files!!!" -----------------------------------------------

## Do you really?
my_file <- "a,b\n1,'a'\n2,'b'"
dat <- read.table(header = TRUE, text = my_file, sep = ",")
mean(dat$a)

## If you really, really need files on disk, use temp files
## https://github.com/r-lib/roxygen2md/issues/4

# Output options ---------------------------------------------------------------

# Default is GitHub-flavored markdown

# HTML
reprex({
  dat <- data.frame(a = 1:2, b = LETTERS[1:2])
  mean(dat$a)
}, venue = "html")

# R
reprex({
  dat <- data.frame(a = 1:2, b = LETTERS[1:2])
  mean(dat$a)
}, venue = "r")

# RTF - nice for presentations, copy/paste into Keynote
reprex({
  dat <- data.frame(a = 1:2, b = LETTERS[1:2])
  mean(dat$a)
}, venue = "rtf")


# Session info -----------------------------------------------------------------

reprex({
  dat <- data.frame(a = 1:2, b = LETTERS[1:2])
  mean(dat$a)
}, session_info = TRUE)