Códigos do Curso

"aniv" <- function(n, p){
  if(missing(n) && missing(p))
    error("um dos argumentos, n ou p deve ser fornecido")
  if(!missing(n) && !missing(p))
    error("apenas um dos argumentos, n ou p deve ser fornecido")
  Prob <- function(n) 1 - exp(sum(log(365:(365-n+1))) - n*log(365))
  VecProb <- Vectorize(Prob, "n")
  if(missing(n))
    res <- sapply(p, function(y) which((VecProb(1:366) - y) > 0)[1])
  if(missing(p))
    res <- VecProb(n)
  return(res)
}
 
aniv(n=23) 
aniv(n=c(36,41, 50))
aniv(n=c(10, 20, 35, 50, 57))
aniv(n=366)
plot(1:366, aniv(n=1:366), type="l", xlab="n", ylab="P[Coincidencia]")
 
aniv(p=0.5)
aniv(p=c(0.2, 0.4, 0.5, 0.7, 0.9, 0.99))
 
plot(1:100, aniv(n=1:100), type="l", xlab="n", ylab="P[Coincidencia]")
arrows(c(1,aniv(p=0.5)),c(0.5, 0.5),c(aniv(p=0.5),aniv(p=0.5)),c(0.5,0), length=0.1)
text(1, 0.5, 0.5, pos=2, off=0.1, cex=0.7)
text(aniv(p=0.5),0 ,aniv(p=0.5), pos=1, off=0.2, cex=0.7)

"nTenta" <- function(N, padrao="HTT", media = TRUE){
  padrao <- strsplit(padrao, NULL)[[1]]
  nc <- length(padrao)
  nTenta <- numeric(N)
  for(i in 1:N){
    res <- sample(c("H","T"), nc, rep=T)
    n <- nc
    while(any(res != padrao)){
      res <- c(res[2:nc],  sample(c("H","T"), 1, rep=T))
      n <- n+1
    }
    nTenta[i] <- n
  }
  if(media) return(mean(nTenta))
  else return(nTenta)
}
 
J1 <- nTenta(100, "HTT", med=F)
J2 <- nTenta(100, "HTH", med=F)
J1
J2
mean(J1)
mean(J2)
 
n1 <- nTenta(10000, "HTT", med=F)
plot(table(n1))
 
nTenta(100000, "HTT")
nTenta(100000, "HTH")

"jogo" <- function(){
  cartas <- LETTERS[1:3]
  premio <- sample(cartas, 1)
  escolha <- sample(cartas, 1)
  sobra <- cartas[which(cartas != escolha)]
  mostra <- sample(sobra[which(sobra != premio)], 1)
  NTroca <- escolha
  Res.NT <- ifelse(NTroca == premio, "Ganhou", "Perdeu")
  Troca <- sobra[sobra != mostra]
  Res.T <- ifelse(Troca == premio, "Ganhou", "Perdeu")
  return(c(premio, escolha, mostra, NTroca, Res.NT, Troca, Res.T))
}
 
jogo()
 
set.seed(231)
sim <- as.data.frame(t(replicate(10000, jogo())))
names(sim) <- c("premio", "escolha", "mostra", "NTroca", "Res.NT", "Troca", "Res.T")
dim(sim)
head(sim)
 
prop.table(table(sim$Res.NT))
prop.table(table(sim$Res.T))