R rpois() Function - Generate Poisson Distribution Random Numbers
R Language ExamplesThe R rpois() function is used to generate random numbers that follow a Poisson distribution.
The Poisson distribution describes the number of times a random event occurs in a fixed time or space interval. It is often used to simulate website visits, phone call volume, etc.
The syntax of the rpois() function is as follows:
rpois(n, lambda) dpois(x, lambda) # 概率质量函数 ppois(q, lambda) # 累积分布函数
Parameter description:
nThe number of random numbers to generate.
lambdaThe average number of events occurring per unit time (mean).
Example
# Simulate an average of 5 visits per hour, generate visit counts for 24 hours
set.seed(123)
hourly_visits <- rpois(24, lambda = 5)
print("Visits per hour for 24 hours:")
print(hourly_visits)
# dpois: probability of exactly 3 visits in one hour
prob_3 <- dpois(3, lambda = 5)
print(paste("Probability of exactly 3 visits:", round(prob_3, 4)))
# ppois: probability of more than 8 visits in one hour
prob_over_8 <- 1 - ppois(8, lambda = 5)
print(paste("Probability of more than 8 visits:", round(prob_over_8, 4)))
set.seed(123)
hourly_visits <- rpois(24, lambda = 5)
print("Visits per hour for 24 hours:")
print(hourly_visits)
# dpois: probability of exactly 3 visits in one hour
prob_3 <- dpois(3, lambda = 5)
print(paste("Probability of exactly 3 visits:", round(prob_3, 4)))
# ppois: probability of more than 8 visits in one hour
prob_over_8 <- 1 - ppois(8, lambda = 5)
print(paste("Probability of more than 8 visits:", round(prob_over_8, 4)))
Executing the above code produces the following output:
[1] "24 小时每小时访问量:" [1] 4 6 7 3 4 6 6 7 3 1 5 6 6 6 4 6 3 3 4 5 4 10 4 4 [1] "恰好 3 次访问的概率: 0.1404" [1] "超过 8 次访问的概率: 0.0681"Other Extensions