title: R Markdown makes custom plot disappear if I set echo=FALSE
body: <p>I created a custom function which sets mfrow to nxn and creates n^2 scatter plots, with multiple data sets on each plot, based on an input list of data frames.  The signature of my plotting function looks like this:</p>
  
  <pre><code>plot.return.list&lt;-function(df.list,num.plot,title)
  </code></pre>
  
  <p>Where <code>df.list</code> is my list of data frames, <code>num.plot</code> is the total number of plots to generate (used to set <code>mfrow</code>) and <code>title</code> is the overall plot title (the function generates titles for each individual sub-graph).</p>
  
  <p>This creats plots fine when I run the function from the console.  However, I'm trying to get this figure into a markdown document using RStudio, like so:</p>
  
  <pre><code>```{r, fig.height=6,fig.width=6} 
  plot.return.list(f.1.list,4,bquote(atop("Numerical Approximations vs Exact Soltuions for "
  ,dot(x)==-1*x*(t))))
  ```
  </code></pre>
  
  <p>Since I haven't set the <code>echo</code> option in my <code>{r}</code> statement, this prints both the plotting code as well as the plot itself.  However, if my first line instead reads: </p>
  
  <pre><code>{r, fig.height=6,fig.width=6,echo=FALSE} 
  </code></pre>
  
  <p>Then both the code AND the plot disappear from the final document.  </p>
  
  <p>How do I make the plot appear WITHOUT the code?  According to the example RStudio gives, setting <code>echo=FALSE</code> should make the plot appear without the code, but that isn't the behavior I'm observing.</p>
  
  <p><strong>EDIT:</strong> I seem to have tracked my problem down to <code>kable</code>.  Whether or not I'm making a custom plot-helper function, any call to <code>kable</code> kills my plot.  This can be reproduced in a markdown:</p>
  
  <pre><code>---
  title: "repro"
  author: "Frank Moore-Clingenpeel"
  date: "October 9, 2016"
  output: pdf_document
  ---
  
  ```{r setup, include=FALSE}
  knitr::opts_chunk$set(echo = TRUE)
  library(knitr)
  options(default=TRUE)
  repro.df&lt;-data.frame((0.1*1:10)%*%t(1:10)) 
  ```
  ```{r, echo=FALSE}
  kable(repro.df)
  ```
  ```{r, fig.height=6,fig.width=6,echo=FALSE} 
  plot(repro.df[,1],repro.df[,2])
  ```
  </code></pre>
  
  <p>In this code, the plot won't plot because I have <code>echo</code> set to false; removing the flag makes the plot visible</p>
  
  <p>Also note that in my repro code, <code>kable</code> produces a table with a bunch of garbage in the last line--I don't know why, but this isn't true for my full original code, and I don't think it's related to my problem.</p>