title: Creating a scatter plot with multiple (>10) variables from repeated measures in SPSS
body: <p>Some <strong>explaining facts</strong> in the beginning:
  I have got my data structured in SPSS in the following way.
  I've got 20 variables (case_number, a_1, b_1, c_1, a_2, b_2, c_2, ....)
  The variables are named in such a way because I took repeated measures (at different points of time, here named 1 and 2) with different devices (named a, b and c). All devices are supposed to measure the same.</p>
  
  <p><strong>What I want to do</strong> now is create a <strong>scatter plot for all devices</strong> and <strong>all points of time</strong>, e.g. I would like to have device a on the x-axis and devices b and c on the y-axis and then plot
  (a_1, b_1)
  (a_1, c_1)
  (a_2, b_2)
  (a_2, c_2) 
  and so on.</p>
  
  <p>I would like <strong>all points that use device b</strong> on the y-axis to have the same color (e.g. <strong>green</strong>), p<strong>oints using device c</strong> should have <strong>another color</strong> (e.g. red).
  I do NOT want to use different colors for different points of time, so both (a_1, b_1) and (a_2, b_2) should be green.</p>