title: Time Series Plot Matrix
body: <p>I have a question concerting R:
  I was trying to plot a set of daily time series commodity data in R with the package <code>ggplot2</code> and <code>ggfortify</code> into a matrix. I am trying to have standardized values on each y axis and the dates 1/1/2007, 1/1/2008... on the x axis. 
  The visual concept should look like this:</p>
  
  <p><img src="https://i.stack.imgur.com/FEKIb.png" alt="enter image description here"></p>
  
  <p>Does anyone know how that works ?</p>