<diagram dimensions="(300,300)" margins="5">
  <definition>f(t,y) = (y[1], -pi*y[0]-0.3*y[1])</definition>
  <coordinates bbox="[-1,-3,6,3]">
    <grid-axes xlabel="t"/>
    <de-solve function="f" t0="0" t1="bbox[2]"
              y0="(0,2)" name="oscillator"
              N="200"/>
    <plot-de-solution at="x" solution="oscillator"
                      axes="(t,y0)" />
    <plot-de-solution at="xprime" solution="oscillator"
                      axes="(t,y1)" stroke="red"
                      tactile-dash="9 9"/>
    <legend at="legend" anchor="(bbox[2], bbox[3])"
            alignment="sw" scale="0.9" opacity="0.5">
      <item ref="x"><m>x(t)</m></item>
      <item ref="xprime"><m>x'(t)</m></item>
    </legend>
  </coordinates>
</diagram>
