/sci/ - Science & Math

[Anonymous No.2352465]

Help with Matlab anyone?

I'm doing the double pendulum simulation and I've been trying to render a poincare map for it for ages.
I have 4 variables of the system:
Theta1, theta2, dttheta1 and dttheta2 (Being the angular velocity of course)
The code is running with the values being calculated with ode45 but I can't seem to be able to print them to a txt file while running it.

Any help?

[Anonymous No.2352486]

Source?

[Anonymous No.2352741]

bump

[Anonymous No.2352771]

No need to print them while it's running. The output of ode45 is a complete trajectory. Just take that vector and save it

[Anonymous No.2352775]

>pendulum

[Anonymous No.2353085]

>>2352771
How do I do that?

[Anonymous No.2353142]

>>2352771
this
>>2353085
fuck, you're worthless. "help ode45". the output is [T,Y]=ode45(arguments).

>mfw morons do nonlinear differential equations, try to create manifold diagrams, but don't understand how the fuck simple matlab shit works.

[Anonymous No.2353190]

Pendulum

[Anonymous No.2353225]

>>2353142
Oh shut up, I don't know matlab.

[Anonymous No.2353924]

>>2353142
Okay, so I used the [T, Y] command.
Where does the output show?
I really am a noob, sorry.

[Anonymous No.2353935]

>>2353190
>Pendulum
Holy shit, there's 6 members in Pendulum?!

I guess they need the extra man power to make songs THAT shit

[Anonymous No.2353947]

Okay I have

[T, Y]=ode45(@dp_eq,[0 duration], ivp);
With
ivp=[theta1; dttheta1; theta2; dttheta2; g; m1; m2; l1; l2];
Where the first four are the only variables

Now how do I plot theta1 vs. dttheta1?

[Anonymous No.2354072]

>>2353935
who the fuck listens to pendulum?

[Anonymous No.2354400]

>>2354072
Me.

[Anonymous No.2354748]

>>2353947
From what I can tell here it should be
Subplot(111); Plot(Y(:,1),Y(:,3));