autotests/input/highlight.R

0001 ## R Script Sample File
0002 ## Source: http://www.rexamples.com
0003
0004 ## Basics
0005 a <- 42
0006 A <- a * 2  # R is case sensitive
0007 print(a)
0008 cat(A, "\n") # "84" is concatenated with "\n"
0009 if(A>a) # true, 84 > 42
0010 {
0011   cat(A, ">", a, "\n")
0012 }
0013
0014 ## Functions
0015 Square <- function(x) {
0016   return(x^2)
0017 }
0018
0019 print(Square(4))
0020 print(Square(x=4)) # same thing
0021
0022 DoSomething(color="red",number=55)
0023
0024 ## Countdown
0025 countdown <- function(from)
0026 {
0027   print(from)
0028   while(from!=0)
0029   {
0030     Sys.sleep(1)
0031     from <- from - 1
0032     print(from)
0033   }
0034 }
0035
0036 countdown(5)
0037
0038 ## Reading user input
0039 readinteger <- function()
0040 {
0041   n <- readline(prompt="Enter an integer: ")
0042   n <- as.integer(n)
0043   if (is.na(n)){
0044     n <- readinteger()
0045   }
0046   return(n)
0047 }
0048 print(readinteger())
0049
0050 readinteger <- function()
0051 {
0052   n <- readline(prompt="Enter an integer: ")
0053   if(!grepl("^[0-9]+$",n))
0054   {
0055     return(readinteger())
0056   }
0057
0058   return(as.integer(n))
0059 }
0060 print(readinteger())
0061
0062 ## Guess a random number game
0063 readinteger <- function()
0064 {
0065   n <- readline(prompt="Enter an integer: ")
0066   if(!grepl("^[0-9]+$",n))
0067   {
0068     return(readinteger())
0069   }
0070   return(as.integer(n))
0071 }
0072
0073 # real program start here
0074
0075 num <- round(runif(1) * 100, digits = 0)
0076 guess <- -1
0077
0078 cat("Guess a number between 0 and 100.\n")
0079
0080 while(guess != num)
0081 {
0082   guess <- readinteger()
0083   if (guess == num)
0084   {
0085     cat("Congratulations,", num, "is right.\n")
0086   }
0087   else if (guess < num)
0088   {
0089     cat("It's bigger!\n")
0090   }
0091   else if(guess > num)
0092   {
0093     cat("It's smaller!\n")
0094   }
0095 }
0096
0097 ## Lists
0098 sum(0:9)
0099 append(LETTERS[1:13],letters[14:26])
0100 c(1,6,4,9)*2
0101 something <- c(1,4,letters[2])  # indices start at one, you get (1,4,"b")
0102 length(something)
0103
0104 ## margrittr's pipe
0105 diamonds %>%
0106   filter(price > 1000) %>%
0107   group_by(cut) %>%
0108   tally() %>%
0109   rename(tally = n) %>%
0110   arrange(-tally) %>%
0111   mutate(pct = tally / sum(tally)) -> df
0112
0113 ## R native pipes (R > 4.1)
0114 Sys.setenv("_R_USE_PIPEBIND_"= TRUE)
0115 mtcars |> x => lm(mpg ~ cyl, data = x)
0116
0117 ## ggplot2
0118 plot = ggplot(diamonds, aes(x = price, y = carat)) +
0119   geom_point(alpha = 0.3, colour = 'steelblue') +
0120   labs(
0121     title = "ggplot diamonds",
0122     x = "Price, $",
0123     y = "Carat"
0124   ) +
0125   facet_wrap(~ cut) +
0126   theme_minimal()
0127
0128 plot + coord_flip()