为什么all.equal在dplyr的mutate函数中不起作用？ [英] Why doesn't all.equal work within dplyr's mutate function?

问题描述

请考虑以下代码：

library(dplyr)       
patientID <- c(1, 2, 3, 4)
age <- c(25, 34, 28, 52)
diabetes <- c("Type1", "Type2", "Type1", "Type1")
status <- c("Poor", "Improved", "Excellent", "Poor")
patientdata <- data.frame(patientID, age, diabetes, status)
myf <- function(patientID, age, diabetes, status) { isTRUE(all.equal(age, 34))}
mutate(patientdata, isAge34 = myf(patientID, age, diabetes, status))

我写了 myf 返回 TRUE 表示 age == 34 的行，但这不起作用：

I wrote myf to return TRUE for the row where age == 34, but this doesn't work:

  patientID age diabetes    status isAge34
1         1  25    Type1      Poor   FALSE
2         2  34    Type2  Improved   FALSE
3         3  28    Type1 Excellent   FALSE
4         4  52    Type1      Poor   FALSE

为什么没有用？我做错了吗？

Why didn't this work? Did I doing something wrong?

编辑：这是一个人为的简化示例。实际上，我的函数内部逻辑复杂得多。

This is a contrived, simplified example. In reality, I have much more complicated logic inside of my function.

我发问的动机：

• 我认为我应该更喜欢 isTRUE（all.equal（））而不是 == 因为这是R的处理方式。

• I thought that I was supposed to prefer isTRUE(all.equal()) over == because that's the R way of doing things.

参考1 ，参考2 ：

对于数值和复数值，请记住==和！=不允许分数的有限表示或舍入错误。将all.equal与same一起使用几乎总是可取的。请参见示例。

For numerical and complex values, remember == and != do not allow for the finite representation of fractions, nor for rounding error. Using all.equal with identical is almost always preferable. See the examples.

推荐答案

为 @ DavidArenburg说， all.equal（）

As @DavidArenburg said, all.equal() is not vectorized.

以下代码将起作用：

mutate(patientdata, isAge34 = age == 34)

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