在R中使用apply时如何打印当前行的名称? [英] How to print the name of current row when using apply in R?

问题描述

例如，我有一个矩阵 k

> k
  d e
a 1 3
b 2 4

我想在 k 上应用一个函数

I want to apply a function on k

> apply(k,MARGIN=1,function(p) {p+1})
a b
d 2 3
e 4 5

但是，我还想打印 apply 所在行的 rowname，以便我可以知道当时应用了该函数的哪一行.

However, I also want to print the rowname of the row being apply so that I can know which row the function is applied on at that time.

它可能看起来像这样:

apply(k,MARGIN=1,function(p) {print(rowname(p)); p+1})

但我真的不知道如何在 R 中做到这一点.有人知道吗?

But I really don't do how to do that in R. Does anyone has any idea?

推荐答案

据我所知你不能用 apply 做到这一点，但你可以遍历 rownames你的数据框.蹩脚的例子:

As far as I know you cannot do that with apply, but you could loop through the rownames of your data frame. Lame example:

lapply(rownames(mtcars), function(x) sprintf('The mpg of %s is %s.', x, mtcars[x, 1]))

这篇关于在R中使用apply时如何打印当前行的名称?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！