Knitr无视fig.pos？

Question

我试图在RMarkdown文档中插入一个图形，但在使其出现在正确的位置时遇到了问题。下图显示了问题:当使用插图标题时，插图显示在页面的顶部，而不是文档中相关段落的下方。

​

下面是这个最小工作示例的代码：

---
title: "Untitled"
author: "Author"
date: "27 February 2017"
output: 
  pdf_document:
    fig_cap: yes
    keep_tex: yes
---

```{r setup, include=FALSE}

knitr::opts_chunk$set(echo = TRUE，fig.pos= "h")

## 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>.

\newpage

## Including Plots

You can also embed plots, for example:

```{r pressure, echo=FALSE, fig.cap = "Hello"}

绘图(压力)

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

下面是LaTeX输出的相关部分；请注意，忽略了fig.pos选项：

You can also embed plots, for example:

\begin{figure}
\centering
\includegraphics{test_files/figure-latex/pressure-1.pdf}
\caption{Hello}
\end{figure}

Note that the \texttt{echo\ =\ FALSE} parameter was added to the code
chunk to prevent printing of the R code that generated the plot.

我的设置如下所示。我很确定这在之前的版本中是有效的，但是我不知道是哪一个版本。

> sessionInfo()
R version 3.3.2 (2016-10-31)
Platform: x86_64-w64-mingw32/x64 (64-bit)
Running under: Windows >= 8 x64 (build 9200)

locale:
[1] LC_COLLATE=English_United Kingdom.1252  LC_CTYPE=English_United Kingdom.1252   
[3] LC_MONETARY=English_United Kingdom.1252 LC_NUMERIC=C                           
[5] LC_TIME=English_United Kingdom.1252    

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

loaded via a namespace (and not attached):
 [1] backports_1.0.5 magrittr_1.5    rprojroot_1.2   htmltools_0.3.5 tools_3.3.2    
 [6] yaml_2.1.14     Rcpp_0.12.9     stringi_1.1.2   rmarkdown_1.3   knitr_1.15.1   
[11] stringr_1.2.0   digest_0.6.12   evaluate_0.10  

Answer 1

chunk选项fig.pos仅在认为必须写出LaTeX figure环境而不是纯Markdown ![]()时使用，并且仅当指定了图形标题(fig.cap)时才写入LaTeX，并且至少指定了以下选项之一：fig.align、out.width、out.extra。如果您想要强制knitr为图形编写LaTeX代码并使用fig.pos，您可以设置chunk选项out.extra = ''。

Answer 2

我知道Yihui Xie已经回答了这个问题，但我有一个替代的解决方案，它可以避免包含out.extra = ''或任何其他给出的选项，同时也不会干扰没有字幕的图形。

只需添加latex包'float'并使用\floatplacement{figure}{H}来确保每个带有标题的图形在文本中按照您想要的顺序呈现。或者它可以添加到RMarkdown编织pdf时使用的.tex文件中，但我对此相当陌生，还没有时间自己研究这个选项。

我通过查看来自Chestar Ismay的包中的.tex文件找到了这个修复

只需在YAML中添加三行代码，就可以很容易地解决这个问题。我没有足够的声誉来发布它工作的屏幕截图，但你可以复制我所做的并亲自尝试！

---
title: "Untitled"
author: "Author"
date: "27 February 2017"
header-includes: #allows you to add in your own Latex packages
- \usepackage{float} #use the 'float' package
- \floatplacement{figure}{H} #make every figure with caption = h
output: 
  pdf_document:
    fig_cap: yes
    keep_tex: yes
---

```{r setup, include=FALSE}

knitr::opts_chunk$set(echo = TRUE，fig.pos= "h")

## 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>.

\newpage

## Including Plots

You can also embed plots, for example:

```{r pressure, echo=FALSE, fig.cap = "Hello"}

绘图(压力)

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