Question

希望这很简单。我似乎无法拼凑出答案。我有一个数据框。对于每一行，我都需要将值更改为NA。它与每行需要更改的值不同。我想根据指定列中的值将每行的值更改为NA。

    mydata = as.data.frame(rbind(c("AA","CC","BB","DC","CC"),c("CC","CC","BB","DC","BB"),c("BB","BB","BB","DC","DC")))

    > mydata
      V1 V2 V3 V4 V5
    1 AA CC BB DC CC
    2 CC CC BB DC BB
    3 BB BB BB DC DC

    #for each row, replace values that match the value in column 5 with NA
    apply(mydata[,1:4], 1, function(x){
    x[x %in% x$V5]  = NA
    })

期望的输出

    > mydata
      V1 V2 V3 V4 V5
    1 AA NA BB DC CC
    2 CC CC NA DC BB
    3 BB BB BB NA DC

谢谢！

---- ---- UPDATE

使用arvi1000中的以下代码非常适合将一行中的值与一列值进行比较。有没有办法做这样的事情，但比较两个或更多列的值？

当前代码

    mydata[,1:4][mydata[,1:4]==mydata[,5]] <- NA

假设我也有一列6.按行，我想将第5列或第6列中不等于值的值更改为NA。

    mydata = as.data.frame(rbind(c("AA","CC","BB","DC","CC","AA"),c("CC","CC","BB","DC","BB","CC"),c("BB","BB","BB","DC","DC","BB")),stringsAsFactors=F)

    > mydata
      V1 V2 V3 V4 V5 V6
    1 AA CC BB DC CC AA
    2 CC CC BB DC BB CC
    3 BB BB BB DC DC BB

期望的输出

    > mydata
      V1 V2 V3 V4 V5 V6
    1 AA CC NA NA CC AA
    2 CC CC BB NA BB CC
    3 BB BB BB DC DC BB

我试图这样做，但收到错误

 mydata[,1:4][mydata[,1:4]==mydata[,5]|mydata[,6]] <- NA
    Error in mydata[, 1:4] == mydata[, 5] | mydata[, 6] : 
      operations are possible only for numeric, logical or complex types

Answer 1

将stringsAsFactors = F添加到as.data.frame。这是关键，因为'CC'!='CC'当它们是不同因素的不同层次时。

mydata = as.data.frame(rbind(c("AA","CC","BB","DC","CC"),c("CC","CC","BB","DC","BB"),c("BB","BB","BB","DC","DC")),
                       stringsAsFactors=F)

然后：

mydata[,1:4][mydata[,1:4]==mydata[,5]] <- NA

瞧：

  V1   V2   V3   V4 V5
1 AA <NA>   BB   DC CC
2 CC   CC <NA>   DC BB
3 BB   BB   BB <NA> DC

Answer 2

另一种方法是使用apply：

mydata = as.data.frame(rbind(c("AA","CC","BB","DC","CC"),c("CC","CC","BB","DC","BB"),c("BB","BB","BB","DC","DC")))

mydata <- data.frame(t(apply(mydata,1,function(x) {
  for ( i in 1:(ncol(mydata)-1)){
    if ( x[i] == x[ncol(mydata)]) {
      x[i] <- NA
    }  
  }
  return(x)
})))

输出：

> mydata
  V1   V2   V3   V4 V5
1 AA <NA>   BB   DC CC
2 CC   CC <NA>   DC BB
3 BB   BB   BB <NA> DC

按行，将值替换为指定列中的值

2 个答案: