add lab 04

lab04.R

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+# Q1 - Run 10 times and count heads vs tails
+sample(c("Heads", "Tails"), 1)
+sample(c("Heads", "Tails"), 1)
+sample(c("Heads", "Tails"), 1)
+sample(c("Heads", "Tails"), 1)
+sample(c("Heads", "Tails"), 1)
+sample(c("Heads", "Tails"), 1)
+sample(c("Heads", "Tails"), 1)
+sample(c("Heads", "Tails"), 1)
+sample(c("Heads", "Tails"), 1)
+sample(c("Heads", "Tails"), 1)
+
+# *******************************
+FlipOnce = function()
+{
+  headOrTail<-sample(c("Heads", "Tails"), 1)
+  return(headOrTail)
+}
+
+CoinResults = function(n)
+{
+  coinList<-c(1:n)
+  for (i in 1:n)
+  {
+    coinList[i]=FlipOnce()
+  }
+  return(coinList)
+}
+
+ProbHeads=function(n)
+{
+  coinList<-CoinResults(n)
+  numHeads<-sum(coinList=="Heads")
+  return(numHeads / n)
+}
+
+# Q2 Rewrite your CoinResults(n) function in the script window without using 
+# loops
+CoinResults = function(n)
+{
+  coinList<-sample(c("Heads", "Tails"), n, repl=T)
+  return(coinList)
+}
+
+ProbHeads = function(n)
+{
+  coinList<-CoinResults(n)
+  numHeads<-sum(coinList=="Heads")
+  return(numHeads / n)
+}
+
+# Q3 Write a function called MaxAndMinHeads(m,n) that calls ProbsHeads(m) n 
+# times, and returns the maximum and minimum probability of obtaining heads.
+
+MaxAndMinHeads = function(m, n)
+{
+  results<-c(1:n)
+  for (i in 1:n)
+  {
+    results[i] = ProbHeads(m)
+  }
+  return(c(min(results), max(results)))
+}
+
+# Q4 Write a function called RollDie(n) that simulates rolling a die n times, 
+# and returns a bar plot
+RollDie = function(n)
+{
+  rolls<-sample(c(1,2,3,4,5,6), n, repl=T)
+  title<-paste("Distribution of outcomes of", n, "die rolls", sep=" ")
+  plot<-barplot(table(rolls), main=title)
+  return(plot)
+}
+
+# Q5 Write a function called RollSomeDice(n,m) that simulates rolling m dice n 
+# times, and each time counts the number of 3’s obtained in the m dice.
+RollSomeDice = function(n, m)
+{
+  threes<-c(1:n)
+  for (i in 1:n)
+  {
+    rolls<-sample(c(1,2,3,4,5,6), m, repl=T)
+    threes[i]<-sum(rolls==3)
+  }
+  title<-paste("Number of 3's obtained in rolling", m, "dice", sep=" ")
+  plot<-barplot(table(threes), main=title)
+  return(plot)
+}
+
+# Q6 Write a function DrawCardsWithReplacement(n,m) that simulates drawing m 
+# cards from a 52-card deck with replacement, n times.
+DrawCardsWithReplacement = function(n, m)
+{
+  red_counts <- c(1:n)
+  for (i in 1:n)
+  {
+    draws <- sample(c(0,1), m, replace = TRUE)
+    red_counts[i] <- sum(draws== 1)
+  }
+  
+  title<-paste("Number of red cards in", m,
+                 "draws (with replacement)", sep=" ")
+  
+  plot<-barplot(table(red_counts), main = title,
+                  xlab = "Number of red cards",
+                  ylab = "Frequency")
+  return(plot)
+}
+
+# Q7 Now write a function DrawCardsWithoutReplacement(n,m) 
+# that simulates drawing m cards from a 52-card deck without replacement, 
+# n times. For each draw, record the number of red cards. 
+DrawCardsWithoutReplacement = function(n, m)
+{
+  deck <- c(rep(1,26), rep(0,26))
+  red_counts <- c(1:n)
+  
+  for (i in 1:n)
+  {
+    draws <- sample(deck, m, replace = FALSE)
+    red_counts[i] <- sum(draws == 1)
+  }
+  
+  title <- paste("Number of red cards in", m,
+                 "draws (without replacement)")
+  
+  plot <- barplot(table(red_counts),
+                  main = title,
+                  xlab = "Number of red cards",
+                  ylab = "Frequency")
+  return(plot)
+}
+