Orbital elements: Difference between revisions

=={{header|J}}==

{{trans|Raku}}<lang J>NB. euler rotation matrix le,ft hand rule

NB. x: axis (0, 1 or 2), y: angle in radians

R=: {{ ((2 1,:1 2) o.(,-)y*_1^2|x)(,&.>/~0 1 2-.x)} =i.3 }}

X=: +/ .* NB. inner product

orbitalStateVectors=: {{

NB. a: semi-major axis

NB. e: eccentricity

NB. i: inclination

NB. Om: Longitude of the ascending node

NB. w: argument of Periapsis (the other "omega")

NB. f: true anomaly

'a e i Om w f'=: y

l=: a*2:`]@.*1-*:e

'c s'=. 2{.,F=: 2 R f

ra=: l % 1+ e*c

rp=: s*ra*ra%l

ijk=: F X (2 R w)X(0 R i)X(2 R Om)

position=: ra*{.ijk

speed=: (%:(2%ra)-%a)*(%%:@X~) (rp,ra,0) X ijk

position,:speed

}}</lang>

Task example:<lang J> orbitalStateVectors 1 0.1 0 355r678 0 0

0.779423 0.45 0

_0.552771 0.957427 0</lang>