Brownian Motion of

Wind Directions at Hong Kong International Airport

Data from 1997-2023*/

​

let strings = []; // This is the array for rows in CSV file

let angles = []; // This is to store the directions of the winds

let startPoint;

​

function preload() {

  strings = loadStrings("data.csv");

}

​

function setup() {

  createCanvas(400, 400);

  background('rgba(17,66,190,0.71)');

  angleMode(DEGREES);

​

  for (let rowNum = 0; rowNum < strings.length; rowNum++) {

    let angle = split(strings[rowNum], ",")[3];

    if (angle != "***") { // This skips the unavailable data in the file

      angles.push(angle);

    }

  }

  startPoint = createVector(random(20, width), random(20, height)); // The first point

  //is random

  frameRate(120); // Since the size of the data is so huge, increase framrate to speed

  //up the program

}

​

let i = 0; // index for angles array

function draw() {

  noStroke();

  fill(random(100, 255), random(100, 255), random(100, 255));

​

  if (

    // if the point reaches the boundaries, it will start from a random place within 

    // the canavas

    startPoint.x >= width ||

    startPoint.y >= height ||

    startPoint.x < 0 ||

    startPoint.y < 0

  ) {

    startPoint = createVector(random(20, width), random(20, height));

  } else {

    startPoint.add(createVector(sin(angles[i]), cos(angles[i]))); // this makes the 

    // point turn according to the angles in the file

  }

​

  ellipse(startPoint.x, startPoint.y, random(1, 15));

​

  i++;

​

  if (i >= strings.length) {

    print("finished"); // indicate the finish of the program in the console

    noLoop();

  }

}

​