11.07.2015 Views

Principles of Linear Algebra With Mathematica® Rolling an Ellipse ...

Principles of Linear Algebra With Mathematica® Rolling an Ellipse ...

Principles of Linear Algebra With Mathematica® Rolling an Ellipse ...

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

1.2 The First Step 7NextTouch, AxesOrigin→{0, 0}, PlotR<strong>an</strong>ge→{{−3, 8}, {0, 7}}]y6422 2 4 6 8xFigure 1.6: Original ellipse <strong>an</strong>d the rotated ellipse, both at center (2, 4).We have successfully rotated the ellipse, now we need to move it into thecorrect position. This must be a simple shift <strong>of</strong> some kind, but we need to findthe right one, keeping in mind that we wish to automate this process. Theone thing we must be sure <strong>of</strong>, is that the lowest point on the rotated ellipse(corresponding to t = 5.229238282) must move to the point (4, 2) since that ishow far to the right we are rolling the ellipse along the horizontal line. Correspondingly,the original center (2, 4) must therefore be shifted the same amount!LowestPoint = New<strong>Ellipse</strong>[5.229238280827457]{1.42596, −2.21286}ShifT = BotCirc − LowestPoint{2.57404, 4.21286}(NewNew<strong>Ellipse</strong>[t ] = New<strong>Ellipse</strong>[t] + ShifT) // MatrixForm( )2.57404 + 3.84764 Cos[t] + 0.546736 Sin[t]4.21286 − 1.09347 Cos[t] + 1.92382 Sin[t]NewNew<strong>Ellipse</strong>Plot = ParametricPlot[Flatten[NewNew<strong>Ellipse</strong>[t]],{t, 0, 2 π}, PlotStyle→{Thickness[0.007], Blue}];NewCenterPlot = Graphics[{PointSize[0.015], Black,Point[{ShifT}]}];Show[NewNew<strong>Ellipse</strong>Plot, <strong>Ellipse</strong>Plot, TouchPlots, CenterPlot,LinePlot, NextTouch, NewCenterPlot, AxesOrigin→{0, 0},

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!