@cquiroz/aladin-lite/lib/js/SpatialVector.js

AladinLite module

import Constants from "./Constants";
export default class SpatialVector {
  constructor(x, y, z) {
    this.x = x;
    this.y = y;
    this.z = z;
    this.ra_ = 0;
    this.dec_ = 0;
    this.okRaDec_ = false;
  }

  setXYZ(t, s, i) {
    this.x = t;
    this.y = s;
    this.z = i;
    this.okRaDec_ = false;
  }

  length() {
    return Math.sqrt(this.lengthSquared());
  }

  lengthSquared() {
    return this.x * this.x + this.y * this.y + this.z * this.z;
  }

  normalized() {
    var vectorLength = this.length();
    this.x /= vectorLength;
    this.y /= vectorLength;
    this.z /= vectorLength;
  }

  set(lon, lat) {
    this.ra_ = lon;
    this.dec_ = lat;
    this.okRaDec_ = true;
    this.updateXYZ();
  }

  angle(v1) {
    var xx = this.y * v1.z - this.z * v1.y;
    var yy = this.z * v1.x - this.x * v1.z;
    var zz = this.x * v1.y - this.y * v1.x;
    var cross = Math.sqrt(xx * xx + yy * yy + zz * zz);
    return Math.abs(Math.atan2(cross, this.dot(v1)));
  }

  get() {
    return [this.x, this.y, this.z];
  }

  toString() {
    return 'SpatialVector[' + this.x + ', ' + this.y + ', ' + this.z + ']';
  }

  cross(v) {
    return new SpatialVector(this.y * v.z - v.y * this.z, this.z * v.x - v.z * this.x, this.x * v.y - v.x() * this.y);
  }

  equal(other) {
    return Boolean(this.x === other.x && this.y === other.y && this.z === other.z);
  }

  mult(s) {
    return new SpatialVector(s * this.x, s * this.y, s * this.z);
  }

  dot(v1) {
    return this.x * v1.x + this.y * v1.y + this.z * v1.z;
  }

  add(s) {
    return new SpatialVector(this.x + s.x, this.y + s.y, this.z + s.z);
  }

  sub(s) {
    return new SpatialVector(this.x - s.x, this.y - s.y, this.z - s.z);
  }

  dec() {
    if (this.okRaDec_) return this.dec_;
    this.normalized();
    this.updateRaDec();
    return this.dec_;
  }

  ra() {
    if (this.okRaDec_) return this.ra_;
    this.normalized();
    this.updateRaDec();
    return this.ra_;
  }

  updateXYZ() {
    var t = Math.cos(this.dec_ * Constants.C_PR);
    this.x = Math.cos(this.ra_ * Constants.C_PR) * t;
    this.y = Math.sin(this.ra_ * Constants.C_PR) * t;
    this.z = Math.sin(this.dec_ * Constants.C_PR);
  }

  updateRaDec() {
    this.dec_ = Math.asin(this.z) / Constants.C_PR;
    var t = Math.cos(this.dec_ * Constants.C_PR);
    this.ra_ = t > Constants.EPS || -Constants.EPS > t ? this.y > Constants.EPS || this.y < -Constants.EPS ? 0 > this.y ? 360 - Math.acos(this.x / t) / Constants.C_PR : Math.acos(this.x / t) / Constants.C_PR : 0 > this.x ? 180 : 0 : 0;
    this.okRaDec_ = true;
  }

}