title: How to highlight with different color cells that contain a specific string?
body: <p>I'm using the Amelia package in R and after some processing I get a Missingness Map that is all blue: that is good it means all my cells contain <em>something</em>.</p>
  
  <p>Now, what if some cells around the map contain a string value like: <code>draw_me</code>.</p>
  
  <p>Is it possible to draw those cells with a different color?</p>
  
  <p>(I'm free to use any extra/other package)</p>
  
  <p>Example:</p>
  
  <p>CSV file (data.csv):</p>
  
  <pre><code>field1,field2,field3,field4
  3,1,45
  draw_me,1,44,4.4
  1,,draw_me,4
  7,,,9
  543,5,,5
  7.7,draw_me,2,5
  3,2,6,8
  5.5,6,7,8
  3,1,draw_me,6.2
  1,2,3,4
  </code></pre>
  
  <p>R code:</p>
  
  <pre><code>library(Amelia)
  data &lt;- read.csv("data.csv", header = TRUE,na.strings = c("NA","NaN","","#DIV/0!"))
  missmap(data, col=c("gray90", "red"), legend = FALSE, rank.order = FALSE, y.labels = NULL, y.at = NULL)
  data &lt;- data[complete.cases(data),]
  missmap(data, col=c("gray90", "red"), legend = FALSE, rank.order = FALSE, y.labels = NULL, y.at = NULL)
  </code></pre>
  
  <p>Initial missmap:</p>
  
  <p><a href="https://i.stack.imgur.com/ceSkQ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ceSkQ.png" alt="enter image description here"></a></p>
  
  <p>After cleaning out the rows with empty cells:
  <a href="https://i.stack.imgur.com/fIGf4.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/fIGf4.png" alt="enter image description here"></a></p>
  
  <p>What I'm looking for to draw (the blue boxes represent cells with the "draw_me" string in them):</p>
  
  <p><a href="https://i.stack.imgur.com/01vGp.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/01vGp.png" alt="enter image description here"></a></p>