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I'm trying to apply the steps provided in this tutorial in order to linearize a system using Maple.

  1. Create your system of non linear equations
  2. Define your linearization points
  3. Call the Linearize function and you are done.

I've tried with my system but it does not work. So I decided to try with the equations of the pendulum provided by the tutorial. Once the equations are written, I create the system with:

sys3 := [diff(x(t), t) = y(t), diff(theta(t), t) = phi(t), diff(y(t), t) = -(-3*cos(theta(t))*sin(theta(t))*g-2*u(t)+2*m*L*sin(theta(t))*phi(t)^2)/(-3*cos(theta(t))*m+2*M+2*m), diff(phi(t), t) = -(3*(-sin(theta(t))*g*M-sin(theta(t))*g*m-m*u(t)+m^2*L*sin(theta(t))*phi(t)^2))/((-3*cos(theta(t))*m+2*M+2*m)*m*L)]

set the list with the linearization points

lin_point3 := [phi(t) = 0, x(t) = 0, y(t) = 0, theta(t) = 0, u(t) = 0]

But when I call the Linearize function and press enter the enter the output is different from the one in the tutorial.

 lin_model3 := Linearize(sys3, [u(t)], [phi(t), x(t), y(t), theta(t)], lin_point3)

When I press the PrintSystem(lin_model3) command I get a does not evaluate to a module error

How can I get this example working? Solution: Solved using Maple 18.

UserK
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    We cannot tell whether you first executed `with(DynamicSystems);`, what you saw as result from that call to `Linearize`, or whether you entered code as 1D plaintext or 2D input, or which version you're using. The best thing might be for you to upload a worksheet, containing statements which will reproduce the problem when executed, to the www.mapleprimes.com user community. – acer Dec 19 '14 at 05:04
  • I did use `with(DynamicSystems);`. And I entered the code in 2D input mode. Probably the problem is that I'm using an old version of the software. Maple 13.. – UserK Dec 19 '14 at 09:52
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    The `Linearize` command was introduced in Maple 14. You cited the Online Help, which is for the current release. If you look in the help pages of your installed Maple 13 you should be able to see the difference. Here is the M14 updates page, which describes that addition, http://www.maplesoft.com/support/help/Maple/view.aspx?path=updates%2fMaple14%2fpackages#DynamicSystems%20package – acer Dec 19 '14 at 16:07
  • Ok I've tried the example with Maple 18 and it works. Now I'm trying with my system and a new message is returned. More info in the Edit – UserK Dec 20 '14 at 22:00
  • The help page indicates to call, `PrintSystem(lin_model3[1])` and not `PrintSystem(lin_model3)` as you now have in your edits to the posted question. – acer Dec 21 '14 at 02:40
  • I meant that the error was returned with the Linearize command. Maybe I should create another question. – UserK Dec 21 '14 at 17:28
  • @acer please write the answer. – UserK Jan 10 '15 at 21:18

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