Nice piece of Smath.

ODE rkfixed Orbit.sm (10,33 KiB) descargado 1727 vez(es).

Hello Jean,

Thank you for your continuing contributions

By the way, did you use rkfixed() on purpose. As usual, did you try to use, say, Rkadapt() or any other solver different than rkfixed(). As we mentioned many times - rkfixed() is not the solver of choice anyway.

Regards,
Radovan

Wrote

Hello Jean,

Thank you for your continuing contributions

By the way, did you use rkfixed() on purpose. As usual, did you try to use, say, Rkadapt() or any other solver different than rkfixed(). As we mentioned many times - rkfixed() is not the solver of choice anyway.

Regards,
Radovan

Hello Radovan:

Rkadapt represents a pure Newton stable ellipse in this work sheet.
"rkfixed" is a much different story wrt launching satellites.
Some systems have possibly "stiff" solvers, some none directly in Smath
... visit Valery "forced rkfixed".

Cheers Radovan, Jean

ODE rkfixed Orbit.sm (36,62 KiB) descargado 1623 vez(es).
ODE Van der Pol.sm (36,97 KiB) descargado 1551 vez(es).
ODE RK Unsolved [Valery].sm (45,22 KiB) descargado 1264 vez(es).