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The movement of the body around the mass problem!

jkowalski
12-Amethyst

The movement of the body around the mass problem!

hi

I found a book in the movement of the planets around the masses. Rewrote all of the books but does not want to work. I would also like to make this move planets with animate to.

ACCEPTED SOLUTION

Accepted Solutions

Please, find Odesolve command in your sheet. You wrote vector as x,y,x, but it must be x,y,z.

View solution in original post

14 REPLIES 14

Please, find Odesolve command in your sheet. You wrote vector as x,y,x, but it must be x,y,z.

Werner_E
25-Diamond I
(To:jkowalski)

See attached.

Changed parameter in Create Space and type of graph from surface to scatter.

Look what happens if you change the interval in odesolve (from 1 to3 or greater)

Thanks to rosenm for finding the typo.

jkowalski
12-Amethyst
(To:Werner_E)

How animate movments?

Werner_E
25-Diamond I
(To:jkowalski)

A description, esp. the meaning of your vars and functions wouls have been helpful.

Is F(t) a vector describung the position of moving a fifth planet (with mass 0???)

Does the attched help?

BTW, Freemake Video Converter did the job well. THnaks again.

jkowalski
12-Amethyst
(To:Werner_E)

If he was still visible lane 5 planet that would be great. The fifth planet has a mass very much less (close to zero) from 4 others.

Werner_E
25-Diamond I
(To:jkowalski)

Jan Kowalski schrieb:

If he was still visible lane 5 planet that would be great.

So why don't you add the path of the fifth planet?

I am not sure if that animations reflects real situation. What happens at 00:27/00:28 ? Bouncing back from the yellow planet or are we going round that planet so quickly that the animation did not catch it?

jkowalski
12-Amethyst
(To:Werner_E)

The odesolve is the previous value was inaccurate. You have to increase the number of step intervals. Or something like that.

Werner ,rosenm Thanks for your replay.

Werner_E
25-Diamond I
(To:jkowalski)

What happens here? It looks like the red "planet" is rejected by the yellow one.

Shown is the path between t=260 and t=276.

orbit1.png

jkowalski
12-Amethyst
(To:Werner_E)

Try to enter the values ​​shown by arrows(file.gif).Odesolve solves the equation in an approximate manner. The higher the number (intvls) the more accurate solution.


Odesolve([vector], x, b, [intvls])

  • b is the real terminal point of the integration interval. b can be greater than or less than the initial value, which is inferred from the initial conditions in the solve block.
  • intvls (optional) is the integer number of discretization intervals used to interpolate the solution function. The number of solution points is the number of intvls + 1. The default value of intvls is 1000. More is more accurately eg: 50000


in our case it b=500,intvls=20000.

Werner_E
25-Diamond I
(To:jkowalski)

I left b at 400 but the change of the intervals of odesolve does significantly affect the path of that planet. Decent accuracy is achieved by intervals>10^5. But then, solving an DE from 0 to 400 (!!) numerically is quite a task.

Attached the change of the path (t=260 to t=276) when changing the intervals of odesolve from 10^3 to 10^6.

At least it shows the the red planet goes around the yellow one as it should be.

jkowalski
12-Amethyst
(To:Werner_E)

See the example of how the function changes it, odesolve accuracy by changing the step parameter.

see file attached.

Werner_E
25-Diamond I
(To:jkowalski)

Significant, indeed. An the interval we are calculating the solution for is only from 0 to pi, not from 0 to some hundreds as we did with the planets.

jkowalski
12-Amethyst
(To:Werner_E)

WOW unbelievable result!!!!!!!!!!!

Werner_E
25-Diamond I
(To:jkowalski)

Jan Kowalski schrieb:

WOW unbelievable result!!!!!!!!!!!

You are using a numerical approximation and you divide the solve range, which is about 1500 wide, into 100 intervals only. That has to become quite random.

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