爲什麼在rmarkdown循環時datatable不打印？

Question

我正在創建一個動態的rmarkdown文檔。最終結果應該爲數據中的每個「分類」創建一個標籤。每個選項卡都應該有一個來自DT包的數據表，其中打印了數據。下面是我一直使用的代碼：

--- 
output: html_document 
--- 

# Setup{.tabset} 
```{r setup, include=FALSE} 
knitr::opts_chunk$set(echo = FALSE) 
library(knitr) 
library(DT) 
``` 

```{r data.setup} 
set.seed = 1242 
rows = 64 
data.1 = runif(rows, 25, 75) 
data.2 = runif(rows, .01, 1) 
data.3 = runif(rows, 1, 10) 
classification = c("A", "B", "C", "D") 
df = data.frame(cbind(data.1 = data.1, data.2 = data.2, data.3 = data.3, classification = classification)) 
df$data.1 = as.numeric(df$data.1) 
df$data.2 = as.numeric(df$data.2) 
df$data.3 = as.numeric(df$data.3) 
``` 

```{r results= 'asis'} 
for(j in levels(df$classification)){ 
     df.j = df[df$classification == j, ] 
     cat(paste("\n\n## Classification: ", j, "##\n")) 
     w = datatable(df.j) 
     #datatable(df.j) 
     print(w) 
} 
``` 

通知我註釋掉直接呼叫到DataTable功能，那些沒有打印到rmarkdown。調用結果以書面形式生成帶有正確選項卡的html文檔，但其中沒有數據表。此外，數據表格實際上顯示在我的RStudio會話中，具有正確的子集。作爲一個測試，我嘗試使用knitr的kable函數實現目標，並且表格被打印在適當的選項卡中，不幸的是，kable不具備所需的全部功能。

Answer 1

這不是一個完整的答案，因爲其中一些問題仍然令我困惑，但至少這足以讓你走，而我試着去了解更多。

--- 
output: html_document 
--- 

# Setup{.tabset} 
```{r setup, include=FALSE} 
knitr::opts_chunk$set(echo = FALSE) 
library(knitr) 
library(DT) 
``` 

```{r data.setup} 
set.seed <- 1242 
rows <- 64 
data.1 <- runif(rows, 25, 75) 
data.2 <- runif(rows, .01, 1) 
data.3 <- runif(rows, 1, 10) 
classification <- c("A", "B", "C", "D") 
df <- data.frame(cbind(data.1 = data.1, data.2 = data.2, data.3 = data.3, classification = classification)) 
df$data.1 <- as.numeric(df$data.1) 
df$data.2 <- as.numeric(df$data.2) 
df$data.3 <- as.numeric(df$data.3) 
``` 

```{r include = FALSE} 
# Why, oh why do I need this chunk? 
datatable(df) 
``` 

```{r results = 'asis'} 
for(j in unique(df$classification)){ # You were using level() here, so your for-loop never got off the ground 
     df.j <- df[df$classification == j, ] 
     cat(paste("\n\n## Classification: ", j, "##\n")) 
     print(htmltools::tagList(datatable(df.j))) 
} 

第三個塊需要這個工作，我還不確定爲什麼。

Answer 2

通過使用Google搜索相同的問題到達此處。這對我有效：https://gist.github.com/ReportMort/9ccb544a337fd1778179。

基本上，生成呈現的Tibbles列表並手動調用knit。

這裏是一個工作RMD根據你的榜樣，用上面的鏈接中找到的技術：

--- 
output: html_document 
--- 

# Setup{.tabset} 
```{r setup, include=FALSE} 
knitr::opts_chunk$set(echo = FALSE) 
library(knitr) 
library(DT) 
``` 

```{r data.setup} 
set.seed <- 1242 
rows <- 64 
data.1 <- runif(rows, 25, 75) 
data.2 <- runif(rows, .01, 1) 
data.3 <- runif(rows, 1, 10) 
classification <- c("A", "B", "C", "D") 
df <- data.frame(cbind(data.1 = data.1, data.2 = data.2, data.3 = data.3, classification = classification)) 
df$data.1 <- as.numeric(df$data.1) 
df$data.2 <- as.numeric(df$data.2) 
df$data.3 <- as.numeric(df$data.3) 
``` 

```{r include = FALSE} 
# prepare a list of 4 sub-dataframes, each corresponding to one classification 
df_list <- split(df, df$classification) 
``` 

```{r create-markdown-chunks-dynamically, include=FALSE} 

out = NULL 
for (c in names(df_list)) { 
    knit_expanded <- paste0("\n\n## Classification: ", c, "##\n\n```{r results='asis', echo=FALSE}\n\ndatatable(df_list[['", c, "']])\n\n```") 
    out = c(out, knit_expanded) 
} 

``` 

<!--- knit those table chunk statements --> 
`r paste(knit(text = out), collapse = '\n')`