警告消息以与警告无关的块的形式出现在RStudio笔记本中

Question

我开始使用RStudio笔记本,我仍然试图了解一些工作原理.我不明白为什么在执行与消息完全无关的代码时会保留并显示某些生成的警告消息.例如,我有一个包含多个块的文档,其中最后一个生成警告

> warnings()
Warning messages:
1: Unknown or uninitialised column: 'perc.goal.met.period'.
2: Unknown or uninitialised column: 'perc.goal.met.period'.
3: Unknown or uninitialised column: 'perc.goal.met.period'.
4: Unknown or uninitialised column: 'perc.goal.met.period'.
5: Unknown or uninitialised column: 'perc.goal.met.period'.
6: Unknown or uninitialised column: 'perc.goal.met.period'.
7: Unknown or uninitialised column: 'perc.goal.met.period'.
8: Unknown or uninitialised column: 'perc.goal.met.period'.
9: Unknown or uninitialised column: 'perc.goal.met.period'.
10: Unknown or uninitialised column: 'perc.goal.met.period'.
11: Unknown or uninitialised column: 'perc.goal.met.period'.
12: Unknown or uninitialised column: 'perc.goal.met.period'.
13: Unknown or uninitialised column: 'perc.goal.met.period'.
14: Unknown or uninitialised column: 'perc.goal.met.period'.
15: Unknown or uninitialised column: 'perc.goal.met.period'.
16: Unknown or uninitialised column: 'perc.goal.met.period'.
17: Unknown or uninitialised column: 'perc.goal.met.period'.
18: Unknown or uninitialised column: 'perc.goal.met.period'.
19: Unknown or uninitialised column: 'perc.goal.met.period'.
20: Unknown or uninitialised column: 'perc.goal.met.period'.
21: Unknown or uninitialised column: 'perc.goal.met.period'.
22: Unknown or uninitialised column: 'perc.goal.met.period'.
23: Unknown or uninitialised column: 'perc.goal.met.period'.
24: Unknown or uninitialised column: 'perc.goal.met.period'.
25: Unknown or uninitialised column: 'perc.goal.met.period'.
26: Unknown or uninitialised column: 'perc.goal.met.period'.
27: Unknown or uninitialised column: 'perc.goal.met.period'.
28: Unknown or uninitialised column: 'perc.goal.met.period'.
29: Unknown or uninitialised column: 'perc.goal.met.period'.
30: Unknown or uninitialised column: 'perc.goal.met.period'.
There were 30 warnings (use warnings() to see them)

我很满意这个警告.但后来,我想我会在第一个块(我加载它们)中加载一个额外的库.运行该块后,我得到:

```{r echo=F, message=F, warnings=F, include=F}
# Load libraries
library(rgdal)
library(raster)
library(openxlsx)
library(tidyverse)
library(dplyr)
library(magrittr)
library(ggplot2)
library(rasterVis)
```
There were 30 warnings (use warnings() to see them)

如果我看到警告,那就是我之前打过的那些.为什么我在这里看到他们？我也看到这个也与变量无关的其他块perc.goal.met.period.如果我看到警告,他们会停止出现一段时间,但在我仍然无法预料的那一刻,他们最终会在某个时刻重新出现.

这种行为有合理的解释吗？非常感谢你的帮助!

Answer 1

您将看到警告消息，直到您将其清除。运行 warnings() 函数不会执行此操作。要清除警告，您可以执行以下命令：

assign("last.warning", NULL, envir = baseenv())

不过，最好的方法是修复代码，这样就不会产生警告。处理它的一种方法是tryCatch()在 R 中使用。

您还可以使用supressWarnings()function 禁用所有警告，但不建议这样做，因为这会阻止您看到任何警告。