added graphing 2d equations example

src/data/examples/en/08_Math/20_Graphing2DEquations.js

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+/**
+ * @name Graphing 2D Equations
+ * @frame 710, 400
+ * @description Graphics the following equation: sin(n*cos(r) + 5*theta) where n is a function of horizontal mouse location. Original by Daniel Shiffman
+ */
+function setup() {
+  createCanvas(710, 400);
+  pixelDensity(1);
+}
+
+function draw() {
+  loadPixels();
+  let n = (mouseX * 10.0) / width;
+  const w = 16.0; // 2D space width
+  const h = 16.0; // 2D space height
+  const dx = w / width; // Increment x this amount per pixel
+  const dy = h / height; // Increment y this amount per pixel
+  let x = -w / 2; // Start x at -1 * width / 2
+  let y;
+
+  let r;
+  let theta;
+  let val;
+
+  let bw; //variable to store grayscale
+  let i;
+  let j;
+  let cols = width;
+  let rows = height;
+
+  for (i = 0; i < cols; i += 1) {
+    y = -h / 2;
+    for (j = 0; j < rows; j += 1) {
+      r = sqrt(x * x + y * y); // Convert cartesian to polar
+      theta = atan2(y, x); // Convert cartesian to polar
+      // Compute 2D polar coordinate function
+      val = sin(n * cos(r) + 5 * theta); // Results in a value between -1 and 1
+      //var val = cos(r);                            // Another simple function
+      //var val = sin(theta);                        // Another simple function
+      bw = color(((val + 1) * 255) / 2);
+      index = 4 * (i + j * width);
+      pixels[index] = red(bw);
+      pixels[index + 1] = green(bw);
+      pixels[index + 2] = blue(bw);
+      pixels[index + 3] = alpha(bw);
+      y += dy;
+    }
+    x += dx;
+  }
+  updatePixels();
+}

src/data/examples/es/08_Math/20_Graphing2DEquations.js

@@ -0,0 +1,52 @@
+/**
+ * @name Graphing 2D Equations
+ * @frame 710, 400
+ * @description Graphics the following equation: sin(n*cos(r) + 5*theta) where n is a function of horizontal mouse location. Original by Daniel Shiffman
+ */
+function setup() {
+  createCanvas(710, 400);
+  pixelDensity(1);
+}
+
+function draw() {
+  loadPixels();
+  let n = (mouseX * 10.0) / width;
+  const w = 16.0; // 2D space width
+  const h = 16.0; // 2D space height
+  const dx = w / width; // Increment x this amount per pixel
+  const dy = h / height; // Increment y this amount per pixel
+  let x = -w / 2; // Start x at -1 * width / 2
+  let y;
+
+  let r;
+  let theta;
+  let val;
+
+  let bw; //variable to store grayscale
+  let i;
+  let j;
+  let cols = width;
+  let rows = height;
+
+  for (i = 0; i < cols; i += 1) {
+    y = -h / 2;
+    for (j = 0; j < rows; j += 1) {
+      r = sqrt(x * x + y * y); // Convert cartesian to polar
+      theta = atan2(y, x); // Convert cartesian to polar
+      // Compute 2D polar coordinate function
+      val = sin(n * cos(r) + 5 * theta); // Results in a value between -1 and 1
+      //var val = cos(r);                            // Another simple function
+      //var val = sin(theta);                        // Another simple function
+      bw = color(((val + 1) * 255) / 2);
+      index = 4 * (i + j * width);
+      pixels[index] = red(bw);
+      pixels[index + 1] = green(bw);
+      pixels[index + 2] = blue(bw);
+      pixels[index + 3] = alpha(bw);
+
+      y += dy;
+    }
+    x += dx;
+  }
+  updatePixels();
+}

src/data/examples/zh-Hans/08_Math/20_Graphing2DEquations.js

@@ -0,0 +1,52 @@
+/**
+ * @name Graphing 2D Equations
+ * @frame 710, 400
+ * @description Graphics the following equation: sin(n*cos(r) + 5*theta) where n is a function of horizontal mouse location. Original by Daniel Shiffman
+ */
+function setup() {
+  createCanvas(710, 400);
+  pixelDensity(1);
+}
+
+function draw() {
+  loadPixels();
+  let n = (mouseX * 10.0) / width;
+  const w = 16.0; // 2D space width
+  const h = 16.0; // 2D space height
+  const dx = w / width; // Increment x this amount per pixel
+  const dy = h / height; // Increment y this amount per pixel
+  let x = -w / 2; // Start x at -1 * width / 2
+  let y;
+
+  let r;
+  let theta;
+  let val;
+
+  let bw; //variable to store grayscale
+  let i;
+  let j;
+  let cols = width;
+  let rows = height;
+
+  for (i = 0; i < cols; i += 1) {
+    y = -h / 2;
+    for (j = 0; j < rows; j += 1) {
+      r = sqrt(x * x + y * y); // Convert cartesian to polar
+      theta = atan2(y, x); // Convert cartesian to polar
+      // Compute 2D polar coordinate function
+      val = sin(n * cos(r) + 5 * theta); // Results in a value between -1 and 1
+      //var val = cos(r);                            // Another simple function
+      //var val = sin(theta);                        // Another simple function
+      bw = color(((val + 1) * 255) / 2);
+      index = 4 * (i + j * width);
+      pixels[index] = red(bw);
+      pixels[index + 1] = green(bw);
+      pixels[index + 2] = blue(bw);
+      pixels[index + 3] = alpha(bw);
+
+      y += dy;
+    }
+    x += dx;
+  }
+  updatePixels();
+}