[问答] 层次分析法与R软件 [推广有奖]

11楼

Afgr4289ch

发表于 2014-6-2 22:47:36

其中关键的部分是从成对比较阵中算出权向量并做一致性检验。其R代码如下：

代码1：计算权重向量的函数weight

function (B)
{
A = matrix(B, nrow = sqrt(length(B)), ncol = sqrt(length(B)),
      byrow = TRUE)
n = ncol(A)
mul_collect = c(1:n)
for (i in 1:n) mul_collect[i] = prod(A[i, ])
weight = mul_collect^(1/n)
weight_one = weight/sum(weight)
round(weight_one, 4)
}

代码2：计算一致性检验的函数CI_CR

function (B)
{
RI = c(0, 0, 0.58, 0.9, 1.12, 1.24, 1.32, 1.41, 1.45, 1.49,
      1.51)
Wi = weight(B)
n = length(Wi)
if (n > 2) {
      W = matrix(Wi, ncol = 1)
      A = matrix(B, nrow = sqrt(length(B)), ncol = sqrt(length(B)),
         byrow = TRUE)
      AW = A %*% W
      aw = as.vector(AW)
      la_max = sum(aw/Wi)/n
      CI = (la_max - n)/(n - 1)
      CR = CI/RI[n]
      cat("\n CI=", round(CI, 4), "\n")
      cat("\n CR=", round(CR, 4), "\n")
      cat("\n la_max=", round(la_max, 4), "\n\n")
      if (CR <= 0.1) {
         cat(" 通过一致性检验！\n")
         cat("\n Wi: ", round(Wi, 4), "\n")
      }
      else {
         cat(" 请调整判断矩阵！\n")
         Wi = null
         break
      }
}
else if (n <= 2) {
      return(Wi)
}
}

注：本代码由《多元统计分析及R语言建模》作者王斌会老师编写