Jeremy Emmett edited Method.md  over 9 years ago

Commit id: 890b36dcbe4d37ecf7c6950236a69415a362afe9

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To study the evolution of the proto-solar system model, I analyzed how the orbital parameters of the particles and Neptune changed over the course of the simulation. I particularly focused on the orbit parameters of Neptune, which could be studied quantitatively given the data output by the FORTRAN code. The FORTRAN code output calculated raw data, which was plotted and further analyzed using two IDL codes. The first IDL code, orbit_parameters.pro (see attached code), took Neptune orbital radius data as its input. In addition to simply plotting the orbital radius as a function of time, this program used the apoapsis and periapsis of every orbit to calculate semi-major axis $a$, orbital period $p$, and eccentricity $e$ as a function of time, via the following formulae:  \begin {equation}  a=(r_apoapsis+r_periapsis)/2. a=\frac{r_apo+r_peri}  {2}  \end {equation}  \begin {equation}  p=2*(t_apoapsis-t_periapsis) p=2*(t_apo-t_peri)  \end {equation}  \begin {equation}  e=(r_apoapsis-r_periapsis)/(r_apoapsis+r_periapsis) e=(r_apo-r_peri)/(r_apo+r_peri)  \end {equation}