الاحتمالات والعشوائية والمحاكاة

outcomes <- expand.grid(first = 0:1, second = 0:1)
counts <- table(factor(rowSums(outcomes), levels = 0:2))
probabilities <- as.numeric(counts)/nrow(outcomes)
cat("counts=", paste(as.integer(counts), collapse = ","), "\n", sep = "")
cat("probabilities=", paste(probabilities, collapse = ","), "\n", sep = "")
cat("expected successes=", sum((0:2)*probabilities), "\n", sep = "")

counts=1,2,1
probabilities=0.25,0.5,0.25
expected successes=1

التعداد دقيق لأن الأزواج الثنائية الأربعة متساوية الاحتمال وفق تجربتين عادلتين مستقلتين.

set.seed(17)
first <- sample.int(6L, size = 5L, replace = TRUE)
set.seed(17)
second <- sample.int(6L, size = 5L, replace = TRUE)
cat("same within session=", identical(first, second), "\n", sep = "")
cat("draw count=", length(first), "\n", sep = "")
cat("valid faces=", all(first >= 1L & first <= 6L), "\n", sep = "")

same within session=TRUE
draw count=5
valid faces=TRUE

تكرر البذرة السحب في إعداد المولد نفسه؛ ولا نفترض قيماً بعينها أو تطابقاً عبر الإصدارات.