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-
- The RPSC directory contains three example program files Ratio, Poly
- and Orbit which may be run from RPSC. To load any of these files select
- load program or join program from the file access menu and type the name
- of the file into the requester.
-
- Ratio ( short for rationalizer ) is a program that converts a
- fractional number into a ratio of two integers. To run Ratio select
- gosub then select "A". To see how this works divide two prime numbers
- then run ratio. The result will be the two original numbers. Ratio may
- also be used to simplify fractions.
-
- Poly contains two user defined functions. One "P" evaluates
- a polynomial of up to seven terms. The other "Q" evaluates the
- derivative of the same polynomial. To use these you must first dimension
- an eaght element matix "P" and fill it with the coefficients of the
- polynomial low order first unused terms must contain zeros. These may
- be evaluated, graphed, solved, or integrated.
-
- These first two files do not use any of the same labels or
- variables and may be combined using join program.
-
- Orbit contains four programs for all of you space ship navigators.
- These programs operate on two body orbit trajectories expressed in
- canonical units. Elements from vectors ( gosub "E" ) expects a position
- vector "A" and a velocity vector "B" and returns an array containing the
- classical orbital elements "E". Vectors from elements ( gosub "V" )
- expects the array of orbital elements "E" and returns the position
- vector "A" and the velocity vector "B". Position and velocity as a
- function of time ( gosub "K" , "K" for Kepler ) expects an initial position
- vector "A", an initial velocity vector "B", and time "T" and returns
- the position "R" and velocity "V" after time "T". Convert ( gosub "C" )
- converts orbital elements ( "E" ) from one format to another.
-
- "E" the array of classical orbital elements. Elements 0 - 5 are
- required for gosub "V". All angles are in radians. Pariapsis refers
- the point of closest approach. The fundamental plane is defined by
- the I and J unit vectors.
-
- Element # Desciption
- 0 Parameter or semi-latus rectum. The size of the orbit
- measured from the focus perpendicular to the major axis.
- 1 Eccentricity e. The shape of the orbit.
- e = 0 Circle
- 0 < e < 1 Ellipse
- e = 1 Parabola
- e > 1 Hyperbola
- 2 Inclination. The angle from the plane of the orbit to
- the fundamental plane.
- 3 Longitude of the ascending node. The angle in the
- fundamental plane from the I unit vector to the point
- where the satellite crosses the fundamental plane going
- north ( positive K ).
- 4 Argument of periapsis. The angle in the plane of the orbit
- from the ascending node to periapsis.
- 5 True anomaly at epoch. The angle from pariapsis to the
- satellite.
- 6 Argument of latitude at epoch. The angle in the plane of
- the orbit from the ascending node to the position vector.
- 7 True longitude at epoch. The angle from the I unit vector
- to the position vector.
- 8 Radius of periapsis. Minimum distance.
- 9 Radius of apoapsis. Maximum distance.
-
- Convert ( gosub "C" ) makes the following changes. All angles converted
- from degrees to radians.
-
- Element # Change from To
- 0 Semi-major axis Semi-latus rectum
- 1 - no change -
- 2 Degrees Radians
- 3 Degrees Radians
- 4 Longitude of pariapsis Argument of periapsis
- 5 True longitude at epoch True anomaly at epoch
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