小编cbs*_*thu的帖子

我的数据集来自基于计算机的测试,下面给出了一个样本.

x<-data.frame(rbind(c("A","C","A","B","A"),
                    c("M","M","M","M","M"),
                    c("M","M","M","M","M"),
                    c("C","C","A","C","A"),
                    c("C","C","B","C","A"),
                    c("A","C","A","C","B")))

colnames(x)<-c("q1","q2","q3","q4","q5")
rownames(x)<-c("key","c1","c2","c3","c4","c5")
    q1 q2 q3 q4 q5
key  A  C  A  B  A
c1   M  M  M  M  M
c2   M  M  M  M  M
c3   C  C  A  C  A
c4   C  C  B  C  A
c5   A  C  A  C  B

列表示问题,行表示候选.第一行是答案键.M代表没有答案.我需要替换值,使Ms替换为"NA",正确答案为1,错误答案为0. EX.对于q1,正确的答案是"A",因此候选3的值,"C"必须替换为0,因为答案是错误的.

最终数据集应如下所示

      q1   q2   q3   q4   q5
key    A    C    A    B    A
c1  <NA> <NA> <NA> <NA> <NA>
c2  <NA> <NA> <NA> <NA> <NA>
c3     0    1    1 …