場景:
問題:
GNU R:
# Probability with Time ExponentialProbabilityDesity <- function(timeExpect, timeMean) { myPower <- -1 * (timeExpect / timeMean) myProbability <- exp(myPower) / timeMean myProbability } ExponentialCumulativeProbability <- function(timeExpect, timeMean) { myPower <- -1 * (timeExpect / timeMean) myProbability <- 1 - exp(myPower) myProbability } #################################################################### # 平均安檢時間 timeMean <- 12.1 myProbability <- vector(mode="double", 3) # 10 min 內完成安檢機率 timeExpect <- 10 myProbability[1] <- ExponentialCumulativeProbability(timeExpect, timeMean) print(myProbability[1]) # 20 min 內完成安檢機率 timeExpect <- 20 myProbability[2] <- ExponentialCumulativeProbability(timeExpect, timeMean) # 超過 20 min 內完成安檢機率 print(1- myProbability[2]) # 10 ~ 20 min 內完成安檢機率 print(myProbability[2] - myProbability[1]) # 必須在 30 min 內登機 # 從安檢關卡至登機門需時:12 min # 最多安檢時間,否則遲到 timeExpect <- 30 - 12 # 最多安檢時間內機率 myProbability[3] <- ExponentialCumulativeProbability(timeExpect, timeMean) # 超過最多安檢時間內機率,遲到機率 print(1- myProbability[3])