title: How to use walk to silently plot ggplot2 output with purrr
body: <p>I am trying to understand how to use <code>walk</code> to silently (without printing to the console) return <code>ggplot2</code> plots in a pipeline.</p>
  
  <pre><code>library(tidyverse)
  
  # EX1: This works, but prints [[1]], [[2]], ..., [[10]] to the console
  10 %&gt;%
    rerun(x = rnorm(5), y = rnorm(5)) %&gt;%
    map(~ data.frame(.x)) %&gt;%
    map(~ ggplot(., aes(x, y)) + geom_point())
  
  # EX2: This does not plot nor print anything to the console
  10 %&gt;%
    rerun(x = rnorm(5), y = rnorm(5)) %&gt;%
    map(~ data.frame(.x)) %&gt;%
    walk(~ ggplot(., aes(x, y)) + geom_point())
  
  # EX3: This errors: Error in obj_desc(x) : object 'x' not found
  10 %&gt;%
    rerun(x = rnorm(5), y = rnorm(5)) %&gt;%
    map(~ data.frame(.x)) %&gt;%
    pwalk(~ ggplot(.x, aes(.x$x, .x$y)) + geom_point())
  
  # EX4: This works with base plotting
  10 %&gt;%
    rerun(x = rnorm(5), y = rnorm(5)) %&gt;%
    map(~ data.frame(.x)) %&gt;%
    walk(~ plot(.x$x, .x$y))
  </code></pre>
  
  <p>I was expecting example #2 to work, but I must be missing or not understanding something. I want the plots from #1 without the console output.</p>