title: Setting upper and lower bound to the values plotted in a matrix with plot.matrix
body: <p>I am trying to plot the values of a matrix and I need to do it using the <code>library(plot.matrix)</code>. My problem is that some of the matrix have extremely high values which bias the plot and do not allow me to observe graphically the differences of the non-outliers' values.</p>
  <p>To illustrate this, imagine I want to plot the following matrix:</p>
  <pre><code>&gt; a &lt;- matrix(1:9, nrow=3, byrow=TRUE)
  &gt; a[1,3] &lt;- 1000
  &gt; a
      [,1] [,2] [,3]
  [1,]    1    2 1000
  [2,]    4    5    6
  [3,]    7    8    9
  </code></pre>
  <p>Therefore, I would like to avoid considering the <code>a[1,3]</code> value when plotting the matrix (I do not want it to be considered when defining the breaks of the palette or other plot settings).</p>
  <p>After checking the documentation <a href="https://cran.r-project.org/web/packages/plot.matrix/vignettes/plot.matrix.html" rel="nofollow noreferrer">https://cran.r-project.org/web/packages/plot.matrix/vignettes/plot.matrix.htmlI</a> did not find any argument for the function plot plot.matrix which directly allows me to define the range of values to plot - something similar to the x.lim or y.lim arguments.</p>
  <p>Although I already have some other solutions:</p>
  <ul>
  <li>Redefine the matrix substituting these values for <code>NA</code></li>
  <li>Use an adequate definition of breaks</li>
  </ul>
  <p>I was wondering if there is any direct argument to the fuction <code>plot(...)</code> that allows me to do this directly.</p>