noise: add fractal noise example

examples/noise_fractal_2d/README.md

@@ -0,0 +1,16 @@
+# Example - plot_bar 📘
+
+This example demonstrates the usage of the V Scientific Library for generating pink noise.
+
+## Instructions
+
+1. Ensure you have the V compiler installed. You can download it from [here](https://vlang.io).
+2. Ensure you have the VSL installed. You can do it following the [installation guide](https://github.com/vlang/vsl?tab=readme-ov-file#-installation)!
+3. Navigate to this directory.
+4. Run the example using the following command:
+
+```sh
+v run main.v
+```
+
+Enjoy exploring the capabilities of the V Scientific Library! 😊

examples/noise_fractal_2d/main.v

@@ -0,0 +1,54 @@
+module main
+
+import rand
+import vsl.noise
+import vsl.plot
+
+fn main() {
+	// Creation of the noise generator.
+	// Other noise functions and dimensions count are available.
+	rand.seed([u32(3155200429), u32(3208395956)])
+	mut generator := noise.Generator.new()
+	generator.randomize()
+
+	mut x := []f64{}
+	mut y := []f64{}
+	mut z := []f64{}
+
+  // 5 layers of simplex noise
+  octaves := 5
+	persistence := 0.5
+
+	for xx in 0 .. 200 {
+		for yy in 0 .. 200 {
+			mut total := 0.0
+			mut frequency := 1.0
+			mut amplitude := 1.0
+			mut max_value := 0.0
+
+			for _ in 0..octaves {
+				total += generator.simplex_2d(0.03 * xx * frequency, 0.03 * yy * frequency) * amplitude
+				max_value += amplitude
+				amplitude *= persistence
+				frequency *= 2.0
+			}
+
+			// Normalize to [-1, 1]
+			total /= max_value
+			x << xx
+			y << yy
+			z << total
+		}
+	}
+
+	mut plt := plot.Plot.new()
+	plt.heatmap(
+		x: x
+		y: y
+		z: z
+	)
+	plt.layout(
+		title: 'Pink `fractal` noise 2d example'
+	)
+	plt.show()!
+}

examples/noise_simplex_2d/main.v

@@ -11,9 +11,9 @@ fn main() {
 	mut generator := noise.Generator.new()
 	generator.randomize()
 
-	mut x := []f64{cap: 1600}
-	mut y := []f64{cap: 1600}
-	mut z := []f64{cap: 1600}
+	mut x := []f64{}
+	mut y := []f64{}
+	mut z := []f64{}
 
 	for xx in 0 .. 40 {
 		for yy in 0 .. 40 {