使用 kableExtra() 进行条件着色失败，列中有 NA

Question

我使用 kableExtra() 包对 PDF 输出 Rmarkdown 报告中的表格进行条件格式设置。一切都很好，但如果在一列中存在 NA 则会失败。

原始报告包含在特定变量上具有百分比一致性的列（例如 21%（但 % 不在单元格中）），但是如果该值基于少于 10 个答案以保护受试者答案，它将显示 NA，因此，我将在表中列出潜在的 NA。

这里是一个小例子，它适用于一个案例（没有 NA）：

---
output: pdf_document
---

```{r setup}
knitr::opts_chunk$set(echo = TRUE)
# load packages
library(tidyverse)
library(kableExtra)


# example when no NA are resent
df1 <- mtcars %>% select(mpg, cyl, disp)
df1 <- head(df1, 10)
# kable
df1 %>%
  mutate(cyl = cell_spec(cyl, color = if_else(cyl == 8, "teal",
                                              if_else(cyl == 6, "orange", 
                                                      if_else(is.na(cyl), "black", "red"))))) %>%
    kable("latex", escape = F, booktabs = TRUE, linesep = "")

```

这是另一个，当存在 NA 时：

```{r, eval=T}
# example when NA is present
df2 <- mtcars %>% select(mpg, cyl, disp)
df2 <- head(df2, 10)
df2$cyl[df2$cyl == 4] <- NA

# kable
df2 %>%
  mutate(cyl = cell_spec(cyl, color = if_else(cyl == 8, "teal",
                                              if_else(cyl == 6, "orange", "red")))) %>%
    kable("latex", escape = F, booktabs = TRUE, linesep = "")


```

运行块的错误是：

Error in if (substr(color, 1, 1) != "#") { : missing value where 
TRUE/FALSE needed

编织时的错误是：

我还尝试添加第三个 if_else() 评估为 is.na() - 错误保持不变：

# kable
df2 %>%
  mutate(cyl = cell_spec(cyl, color = if_else(cyl == 8, "teal",
                                              if_else(cyl == 6, "orange", 
                                                      if_else(is.na(cyl), "black","red"))))) %>%
    kable("latex", escape = F, booktabs = TRUE, linesep = "")

我的会话信息：

R version 3.5.2 (2018-12-20)
Platform: x86_64-apple-darwin15.6.0 (64-bit)
Running under: macOS Mojave 10.14.2

Matrix products: default
BLAS: /System/Library/Frameworks/Accelerate.framework/Versions/A/Frameworks/vecLib.framework/Versions/A/libBLAS.dylib
LAPACK: /Library/Frameworks/R.framework/Versions/3.5/Resources/lib/libRlapack.dylib

locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
 [1] naniar_0.4.1       shurp2018_0.0.9000 kableExtra_1.0.1   forcats_0.3.0      stringr_1.3.1      dplyr_0.8.0        purrr_0.3.0       
 [8] readr_1.3.1        tidyr_0.8.2        tibble_2.0.99.9000 ggplot2_3.1.0      tidyverse_1.2.1 

Answer 1

看来你有两个问题：

首先，我认为默认情况下，没有设置颜色值。然而，对于某些单元格color = NA，它也不会被覆盖。所以你可以通过设置color = NULL 来解决它（任何其他颜色都会与下一步分配的颜色连接，这会导致麻烦）。所以这对我来说有点作用：

```{r}
# kable
df2 %>%
  mutate(cyl = cell_spec(cyl, color = NULL)) %>% 
  mutate(cyl = cell_spec(cyl, color = if_else(cyl == 8, "teal",
                                              if_else(cyl == 6, "orange", "red")))) %>%
    kable("latex", escape = F, booktabs = TRUE, linesep = "")
```

问题是NA 的颜色现在是红色而不是黑色。

第二个问题是您的ifelse 评估无法正常工作

您还可以单独检查ifelse 函数中发生的情况，以更好地了解此问题：

> with(df2,  if_else(cyl == 8, "teal",
+                    if_else(cyl == 6, "orange", 
+                            if_else(is.na(cyl), "black","red"))))
 [1] "orange" "orange" NA       "orange" "teal"   "orange" "teal"   NA       NA       "orange"

但是您可以通过首先评估 is.na(cyl) 而不是最后一个来使其工作：

df2 %>%
  mutate(cyl = cell_spec(cyl, color = if_else(is.na(cyl), "black", 
                                              if_else(cyl == 8, "teal",
                                                      if_else(cyl == 6, "orange", "red"))))) %>%
  kable("latex", escape = F, booktabs = TRUE, linesep = "")