r - 分配由概率分布通知的特定数量的值(在 R 中)

Question

您好，在此先感谢您的帮助!

我正在尝试生成一个向量，其中包含根据概率分布分配的特定数量的值。例如，我想要一个长度为 31 的向量，包含 26 个零和 5 个 1。 (向量的总和应始终为 5。)但是，向量的位置很重要。为了确定哪些值应该是 1，哪些应该是 0，我有一个概率向量(长度为 31)，如下所示:

probs<-c(0.01,0.02,0.01,0.02,0.01,0.01,0.01,0.04,0.01,0.01,0.12,0.01,0.02,0.01,
0.14,0.06,0.01,0.01,0.01,0.01,0.01,0.14,0.01,0.07,0.01,0.01,0.04,0.08,0.01,0.02,0.01)

我可以根据这个分布选择值，并使用 rbinom 得到一个长度为 31 的向量，但我不能正好选择五个值。

Inv=rbinom(length(probs),1,probs)
Inv
[1] 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 0

有任何想法吗？

再次感谢!

Answer 1

仅使用加权 sample.int 怎么样？选择地点？

Inv<-integer(31)
Inv[sample.int(31,5,prob=probs)]<-1
Inv
[1] 0 0 0 1 0 1 0 0 0 0 1 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0