Orbital elements: Difference between revisions
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Speed : (-0.5527708409604437, 0.9574270831797614, 0.0000000000000000)
Edit source/app.d to start your project.</pre>
=={{header|Java}}==
{{trans|Kotlin}}
<lang Java>import java.util.Arrays;
public class OrbitalElements {
private static class Vector {
private double x, y, z;
public Vector(double x, double y, double z) {
this.x = x;
this.y = y;
this.z = z;
}
public Vector plus(Vector rhs) {
return new Vector(x + rhs.x, y + rhs.y, z + rhs.z);
}
public Vector times(double s) {
return new Vector(s * x, s * y, s * z);
}
public Vector div(double d) {
return new Vector(x / d, y / d, z / d);
}
public double abs() {
return Math.sqrt(x * x + y * y + z * z);
}
@Override
public String toString() {
return String.format("(%.16f, %.16f, %.16f)", x, y, z);
}
}
private static Vector mulAdd(Vector v1, Double x1, Vector v2, Double x2) {
return v1.times(x1).plus(v2.times(x2));
}
private static Vector[] rotate(Vector i, Vector j, double alpha) {
return new Vector[]{
mulAdd(i, Math.cos(alpha), j, Math.sin(alpha)),
mulAdd(i, -Math.sin(alpha), j, Math.cos(alpha))
};
}
private static Vector[] orbitalStateVectors(double semimajorAxis, double eccentricity, double inclination, double longitudeOfAscendingNode, double argumentOfPeriapsis, double trueAnomaly) {
Vector i = new Vector(1, 0, 0);
Vector j = new Vector(0, 1, 0);
Vector k = new Vector(0, 0, 1);
Vector[] p = rotate(i, j, longitudeOfAscendingNode);
i = p[0];
j = p[1];
p = rotate(j, k, inclination);
j = p[0];
p = rotate(i, j, argumentOfPeriapsis);
i = p[0];
j = p[1];
double l = semimajorAxis * ((eccentricity == 1.0) ? 2.0 : (1.0 - eccentricity * eccentricity));
double c = Math.cos(trueAnomaly);
double s = Math.sin(trueAnomaly);
double r = l / (1.0 + eccentricity * c);
double rprime = s * r * r / l;
Vector position = mulAdd(i, c, j, s).times(r);
Vector speed = mulAdd(i, rprime * c - r * s, j, rprime * s + r * c);
speed = speed.div(speed.abs());
speed = speed.times(Math.sqrt(2.0 / r - 1.0 / semimajorAxis));
return new Vector[]{position, speed};
}
public static void main(String[] args) {
Vector[] ps = orbitalStateVectors(1.0, 0.1, 0.0, 355.0 / (113.0 * 6.0), 0.0, 0.0);
System.out.printf("Position : %s\n", ps[0]);
System.out.printf("Speed : %s\n", ps[1]);
}
}</lang>
{{out}}
<pre>Position : (0.7794228433986797, 0.4500000346536842, 0.0000000000000000)
Speed : (-0.5527708409604438, 0.9574270831797618, 0.0000000000000000)</pre>
=={{header|Kotlin}}==
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