visjs-network/lib/network/modules/components/physics/FA2BasedCentralGravitySolver.js

A dynamic, browser-based network visualization library.

import CentralGravitySolver from './CentralGravitySolver'

/**
 * @extends CentralGravitySolver
 */
class ForceAtlas2BasedCentralGravitySolver extends CentralGravitySolver {
  /**
   * @param {Object} body
   * @param {{physicsNodeIndices: Array, physicsEdgeIndices: Array, forces: {}, velocities: {}}} physicsBody
   * @param {Object} options
   */
  constructor(body, physicsBody, options) {
    super(body, physicsBody, options)
  }

  /**
   * Calculate the forces based on the distance.
   *
   * @param {number} distance
   * @param {number} dx
   * @param {number} dy
   * @param {Object<Node.id, Node>} forces
   * @param {Node} node
   * @private
   */
  _calculateForces(distance, dx, dy, forces, node) {
    if (distance > 0) {
      let degree = node.edges.length + 1
      let gravityForce =
        this.options.centralGravity * degree * node.options.mass
      forces[node.id].x = dx * gravityForce
      forces[node.id].y = dy * gravityForce
    }
  }
}

export default ForceAtlas2BasedCentralGravitySolver