# Question:Resolution of ODE of a simple pendulum (2)

November 04 2013
Maple

0

Hello,

I have 2 questions about the resolution of a ODE for the simple pendulum equations.

1) I need to add 'maxfun'=10^7 in the dsolve function. With this option, dsolve works. Can you explain me in a very simple way the principle of this option ? It's just to feel better how this option runs.

2) gamma(t) is a angular parameter.

With

tgammax:=odeplot(sol,[gamma(t),x(t)],0..10,numpoints=200,color=blue,legend="z"):
display(tgammax);

I manage to plot x(gamma) but with gamma in rad.

How can i do to x(gamma) but with gamma in degree? I should do gamma_deg=360/(2*Pi)*gamma(t) but as gamma(t) is defined numerically, this lign doesn't work.

Thank you for helpe

Here some ligns of my code :

Cinit:=D(psi)(0)=0,psi(0)=-0.93,D(x)(0)=0,x(0)=1.13,D(gamma)(0)=0,gamma(0)=0.79;sol:=dsolve({sys,Cinit},numeric,'maxfun'=10^7);
tx:=odeplot(sol,[t,x(t)],0..10,numpoints=200,color=blue,legend="x"):
display(tx);

tgamma:=odeplot(sol,[t,gamma(t)],0..10,numpoints=200,color=blue,legend="gamma"):
display(tgamma);

tgammax:=odeplot(sol,[gamma(t),x(t)],0..10,numpoints=200,color=blue,legend="z"):
display(tgammax);

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