如何从频率表转换为R中的原始数据

Question

假设我有一个频率表：

t = matrix(c(20,10,5,15), ncol=2, dimnames=list(c("yes","no"), c("yes","no")))
t
    yes no
yes  20  5
no   10 15

我想将频率表转换回原始数据。我的代码是（不起作用）：

a = rep(c("yes","no"), colSums(t(t)))
b = rep(c("yes","no"), colSums(t))

table(a,b)
        b
a     no yes
  no  20   5
  yes  0  25

谁能告诉我怎么了？

Answer 1

mat <- matrix(c(20,10,5,15), ncol=2, dimnames=list(c("yes","no"), c("yes","no")))

a <- rep(rep(c("yes", "no"), 2), c(mat))
b <- rep(c("yes", "no"), colSums(mat))
a <- factor(a, levels=c("yes", "no"))
b <- factor(b, levels=c("yes", "no"))


table(a, b)
     b
a     yes no
  yes  20  5
  no   10 15

Answer 2

我想你想从reshape2 使用melt：

test = matrix(c(20,10,5,15), ncol=2, dimnames=list(c("yes","no"), c("yes","no")))

test
#    yes no
#yes  20  5
#no   10 15

library(reshape2)

melt(test)
#  Var1 Var2 value
#1  yes  yes    20
#2   no  yes    10
#3  yes   no     5
#4   no   no    15