title: Plot data with MATLAB biplot with more than 1 color
body: <p>I have 3 groups of data that had PCA performed on them as one group. I want to highlight each variable group with a different color. Prior to this I overlaid 3 biplots. This gives different colors but creates a distortion in the data as each biplot function skews the data. This caused the groups to all be skewed by different amounts, making the plot not a correct representation.</p>
  
  <p>How do I take a PCA scores matrix (30x3) and split it so the first 10x3 is one color, the next 10x3 is another and the third 10x3 is another, without the data being skewed?  </p>