PAF 514 - Lab 01 - West

Function 1: Game Setup | create.game()

Psuedocode:
1. Create a vector with 3 doors (goat, goat, car)
2. Randomize positions for each game
3. Return new game

Code:

create.game <- function()
{
  game <- sample (x = c("goat", "goat", "car"), size = 3, replace = F)
  return(game)
}

Test Code:

create.game()

## [1] "goat" "goat" "car"

create.game()

## [1] "car"  "goat" "goat"

create.game()

## [1] "goat" "car"  "goat"

Function 2: Contestant Selection | select.door()

Psuedocode:
1. Create vector for door numbers (1, 2, 3)
2. Select a RANDOM door
3. Return randomly selected door

Code:

select.door <- function()
{
  doors <- c(1, 2, 3)
  pick <- sample(1:3, size =1, replace = F)
  return(pick)
}

Test Code:

select.door()

## [1] 2

select.door()

## [1] 2

select.door()

## [1] 3

select.door()

## [1] 1

Function 3: Reveal Goat Door | open.goat.door()

Psuedocode:
1. Build off of previous create.game & select_door functions.
2. Create parameters for host to select door (must be goat, can’t be contestants selection)
3. Select Door

Code:

open.goat.door <- function(game, pick) {
  goat.doors <- which(game == "goat") 
  goat.doors<- goat.doors[! goat.doors %in% c(pick)] 
  if (game[goat.doors[1]] == "goat"){
    host.pick <-goat.doors[1]
  } else{
    host.pick <- goat.doors[2]
  }
  return(host.pick)
}

Test Code:

this.game <- create.game()
this.game

## [1] "goat" "car"  "goat"

my.initial.pick <- select.door()
my.initial.pick

## [1] 2

host.choice <- open.goat.door(this.game, my.initial.pick)
host.choice

## [1] 1

Function 4: Stay/Switch | change.door()

Psuedocode:
Create leftover doors object that removes the host selected door
Create if else statement that says IF stay = TRUE, keep pick (original selection)
ELSE switch to the other unopened door

Code: change.door()

change.door <- function(stay=T, host.pick, pick)
{
  doors <- c(1,2,3)
  final.pick <- doors[!doors %in% c(host.pick, pick)]

if (stay) {
  return(pick)
} else{
  return(final.pick)
}
}  

Test Code:

this.game

## [1] "goat" "car"  "goat"

my.initial.pick

## [1] 2

host.choice

## [1] 1

change.door(stay = T, host.choice, my.initial.pick )

## [1] 2

change.door(stay = F, host.choice, my.initial.pick )

## [1] 3

Function 5: Determine winner | determine_winner()

Psuedocode:
1. Build off switch function and original create game function
2. Create if else statement where if final selection is car, WIN, if anything else, LOSE.

Code: determine_winner()

determine_winner <- function(final.pick, game)
{ 
  if (game[final.pick] == "car")
  {return("WIN")
  }
  else {return("LOSE")}
  
}

Test Code:

this.game

## [1] "goat" "car"  "goat"

my.initial.pick

## [1] 2

host.choice

## [1] 1

determine_winner(final.pick = 1, this.game)

## [1] "LOSE"

determine_winner(final.pick = 2, this.game)

## [1] "WIN"

determine_winner(final.pick = 3, this.game)

## [1] "LOSE"

Test Code:

game2 <- create.game()
g2pick <- select.door()
g2hostpick <- open.goat.door(game2, g2pick)

game2

## [1] "goat" "goat" "car"

g2pick

## [1] 2

g2hostpick

## [1] 1

my.final.pick <- change.door(stay = T,
                             host.pick =  g2hostpick,
                             pick = g2pick)

determine_winner(final.pick = my.final.pick,
                 game=game2)

## [1] "LOSE"

my.final.pick <- change.door(stay = F,
                             host.pick =  g2hostpick,
                             pick = g2pick)

determine_winner(final.pick=my.final.pick,
                 game = game2)

## [1] "WIN"

Testing the Code:

## [1] "GAME SETUP"

## [1] "goat" "goat" "car"

## [1] "My initial selection: 2"

## [1] "The opened goat door: 1"

## [1] "My final selection: 2"

## [1] "GAME OUTCOME:"

## [1] "LOSE"

## [1] "GAME SETUP"

## [1] "goat" "goat" "car"

## [1] "My initial selection: 2"

## [1] "The opened goat door: 1"

## [1] "My final selection: 3"

## [1] "GAME OUTCOME:"

## [1] "WIN"