答案如下：
#找到特征所在的位置
getColNumber<-function(data,colname="Class"){
    CN <- colnames(data)
    for (i in 1:ncol(data)){
        if (CN[i] == colname) {
            return (i)
        }
    }
    return (FALSE)
}

#将特征列移到最末
moveColToEnd<-function(data,colname="Class"){
    colNumber <- getColNumber(data,colname)
    data <- data[,c(1:(colNumber-1),(colNumber+1):ncol(data),colNumber)]

    return (data)
}

#调换两列特征的顺序
switchCol<-function(data,col1name,col2name){
    col1Number <- getColNumber(data,col1name)
    col2Number <- getColNumber(data,col2name)
    positionEnd = ncol(data)

    if (col2Number < col1Number) {
        tmp <- col1Number
        col1Number <- col2Number
        col2Number <- tmp
    }

    positionBeforCol1 <- col1Number -1
    positionAfterCol1 <- col1Number +1
    positionBeforCol2 <- col2Number -1
    positionAfterCol2 <- col2Number +1

    newOrder = c()
    if (positionAfterCol2 > ncol(data)){
        positionAfterCol2 = ncol(data)
        newOrder <- c(1:positionBeforCol1,col2Number,positionAfterCol1:positionBeforCol2,col1Number)
    } else {
        newOrder <- c(1:positionBeforCol1,col2Number,positionAfterCol1:positionBeforCol2,col1Number,positionAfterCol2:positionEnd)
    }
    dataNew <- data[,newOrder]

    return (dataNew)
}