根据给定的顺序对数据帧进行排序

Question

可能是一个简单的问题。

我有一个data.frame（样本名称，它们的因子水平以及因子水平的副本）：

df <- data.frame(name=c("DP_A","DP_B","PA_A","PA_B","PA_C"),
                 level=c("DP","DP","PA","PA","PA"),
                 replicate=c("A","B","A","B","C"),
                 stringsAsFactors = F)

以及其中一列的给定所需顺序-因子水平：

level.order <- c("PA","DP")

因此，我想df按level.order（含义df$level）订购。

奖励是，如果我可以第二次添加到level.order我可以订购的产品df$replicate，那么订购产品可以是character（如本例中所示）integer，或它们的组合（例如，A1，A2等）

在这种情况下，顺序df为：

df <- data.frame(name=c("PA_A","PA_B","PA_C","DP_A","DP_B"),
                 level=c("PA","PA","PA","DP","DP"),
                 replicate=c("A","B","C","A","B"),
                 stringsAsFactors = F)

Answer 1

有几种选择。一种是基于match“ level.order' to get the numeric index and then订单”的“级别”列

df[order(match(df$level, level.order)),]

或将“级别”转换为factor指定levels为“ level.order”，然后order在其上

df[order(factor(df$level, levels = level.order)),]