R - 将行连接/复制到上一行的最后一个非空列

Question

获取这个样本数据：

df <- data.frame(id=c("1","2","3","7", "8"),
                 fruit=c("Appl","e","t","Banan","a"),
                 veg=c(NA,"Carro","Dog","","Kale"),
                 animal=c("",NA,NA,NA,"Cat")) 

id   fruit    veg      animal
1    Appl     <NA>     <blank>
2    e        Carro    <NA>
3    t        Dog      <NA>   
7    Banan    <blank>  <NA>
8    a        Kale     Cat      

我想编写一个脚本来检查第 x 行的 id 值是否与第 x 行 -1 连续，如果是，则将第 x 行的第一列连接到最后一个非空、非 NA 行第 x-1 行，然后复制其余列，使其看起来像这样：

id   fruit    veg      animal
1    Apple    Carrot   Dog
2    <Blank>  <Blank>  <Blank>
3    <Blank>  <Blank>  <Blank>   
7    Banana   Kale     Cat
8    <Blank>  <Blank>  <Blank>  

提前致谢！

Answer 1

我认为这将满足您的需求。

df[is.na(df)] = ""
i = 1
while (i < nrow(df) - 1) {
    if (as.numeric(df[i, 1]) + 1 == as.numeric(df[i+1, 1])) {
        j = 4
        while (df[i, j] == "") j = j - 1
        k = 2
        while (df[i+1, k] == "") k = k + 1
        df[i, j] = paste(df[i, j], df[i+1, k], sep="")
        while (j < ncol(df)) {
            j = j + 1
            k = k + 1
            df[i, j] = df[i+1, k]
        }
        df[i, 1] = df[i+1, 1]
        df = df[-(i+1), ]
    } else {
        i = i + 1
    }
}

可能效率不高，因为它会迭代所有行。取决于您在数据集中有多少行。