r - 更改rmarkdown保存由r代码生成的图像的位置

Question

我有一个rmarkdown文档，正在将该文件转换为md文档。
我的问题是我希望将由情节创建的图片放在文件同一目录中的名为Images的文件夹中。

假设我有这个文件：

---
title: "my test"
author: "daniel"
date: "18/08/2015"
output:
  md_document
---

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}
summary(cars)
```

You can also embed plots, for example:

```{r, echo=FALSE}
plot(cars)
```

Note that the `echo = FALSE` parameter was added to the code chunk to prevent printing of the R code that generated the plot.

渲染时我有这个：

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:

    summary(cars)

    ##      speed           dist       
    ##  Min.   : 4.0   Min.   :  2.00  
    ##  1st Qu.:12.0   1st Qu.: 26.00  
    ##  Median :15.0   Median : 36.00  
    ##  Mean   :15.4   Mean   : 42.98  
    ##  3rd Qu.:19.0   3rd Qu.: 56.00  
    ##  Max.   :25.0   Max.   :120.00

You can also embed plots, for example:

![](test_files/figure-markdown_strict/unnamed-chunk-2-1.png)

Note that the `echo = FALSE` parameter was added to the code chunk to
prevent printing of the R code that generated the plot.

我想要那条线

![](test_files/figure-markdown_strict/unnamed-chunk-2-1.png)

是这样的：

![](images/unnamed-chunk-2-1.png)

并将图像放置在那里。

Answer 1

就像是：

---
title: "my test"
author: "daniel"
date: "18/08/2015"
output:
  md_document
---

<!-- README.md is generated from README.Rmd. Please edit that file -->

```{r opts, echo = FALSE}
knitr::opts_chunk$set(
  fig.path = "images/"
)
```

将所有生成的图形保存到 images子目录（如果该目录不存在，则创建该目录）。