R markdown子文档：找不到对象

Question

这似乎是一个非常基本的问题，但不知何故我无法在任何地方找到解决方案。我正在尝试将变量传递给 R markdown 子文档。

在父文档中，我有这个块：

```{r}
var1 = "test-var1!"
cat(knit_child("child.Rmd"), sep = "\n")
```

在子文档中，如果我使用ls()，我可以看到var1 在环境中。但是，如果我尝试使用 var1，我会收到一个 knit 错误：

Error in str(var1) : object 'var1' not found
Calls: <Anonymous> ... withCallingHandlers -> withVisible -> eval -> eval -> str

我尝试在 RStudio 和命令行中编织。

有没有办法在子文档中使用对象？

Answer 1

我创建了一个带有两个默认文件的 MWE，格式为 RStudio，但我无法重现您的错误，尽管我猜输出不是您要查找的那个。

Parent.Rmd 文件：

---
title: "Parent"
author: "Clement Walter"
date: "27/11/2017"
output: html_document
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)
```

## R Markdown

This is an R Markdown document. Markdown is a simple formatting syntax for authoring HTML, PDF, and MS Word documents. For more details on using R Markdown see <http://rmarkdown.rstudio.com>.

When you click the **Knit** button a document will be generated that includes both content as well as the output of any embedded R code chunks within the document. You can embed an R code chunk like this:

```{r}
var = 1
cat(knitr::knit_child("Child.Rmd"), sep = "\n")
```

Child.Rmd 文件：

## R Markdown

This is an R Markdown document. Markdown is a simple formatting syntax for authoring HTML, PDF, and MS Word documents. For more details on using R Markdown see <http://rmarkdown.rstudio.com>.

When you click the **Knit** button a document will be generated that includes both content as well as the output of any embedded R code chunks within the document. You can embed an R code chunk like this:

```{r}
ls()
var + 1
```

输出：