Example for Lorenz attractor (#3018)

* broadcasting * Simplified broadcasting * Updated for broadcasting * Changed to camel case * Camel case and auto formating * Added comments * Skip if matrices have the same size * Fixed issue with undefined variable missing dot in `A._size` * Implemented broadcasting in all functions * Added helper functions * Added function to check for broadcasting rules * Tests for broadcasted arithmetic * Fixed issue with matrix the size of a vector * Documented and updated broadcasting * Included broadcast.test * Included math to syntax when missing * Lorenz attractor --------- Co-authored-by: David Contreras <[email protected]> Co-authored-by: Jos de Jong <[email protected]>
josdejong · Aug 30, 2023 · 856b948 · 856b948
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diff --git a/AUTHORS b/AUTHORS
@@ -217,9 +217,9 @@ Evan Miller <[email protected]>
 Timur <[email protected]>
 Ari Markowitz <[email protected]>
 Jay Wang <[email protected]>
+David Contreras <[email protected]>
 Jaeu Jeong <[email protected]>
 cyavictor88 <[email protected]>
-David Contreras <[email protected]>
 Jakub Riegel <[email protected]>
 Angus Comrie <[email protected]>
 TMTron <[email protected]>

diff --git a/examples/browser/lorenz.html b/examples/browser/lorenz.html
@@ -0,0 +1,53 @@
+<!DOCTYPE html>
+<html lang="en">
+
+<head>
+    <meta charset="UTF-8">
+    <title>math.js | Lorenz Attractor</title>
+    <script src="../../lib/browser/math.js"></script>
+
+    <script src="https://cdn.plot.ly/plotly-2.25.2.min.js" charset="utf-8"></script>
+</head>
+
+<body>
+    <div id="LorenzGraph"></div>
+</body>
+<script defer>
+
+    // define the constants for the Lorenz attractor
+    const sigma = 10
+    const beta = 2.7
+    const rho = 28
+
+    // solve the Lorenz attractor
+    const sol = math.solveODE(lorenz, [0, 100], [1, 1, 1])
+
+    // make colors that represents time differences in the solution
+    const diff = math.diff(sol.t)
+    const color = [diff[0], ...diff]
+
+    // render the plot using plotly
+    Plotly.newPlot('LorenzGraph',
+        [{
+            x: sol.y.map(u => u[0]),
+            y: sol.y.map(u => u[1]),
+            z: sol.y.map(u => u[2]),
+            line: { color, colorscale: 'Jet' },
+            type: "scatter3d",
+            mode: "lines"
+        }],
+        { width: 800, height: 600 }
+    )
+
+    // define the lorenz attractor
+    function lorenz(t, u) {
+        const [x, y, z] = u
+        return [
+            sigma * (y - x),
+            x * (rho - z) - y,
+            x * y - beta * z
+        ]
+    }
+</script>
+
+</html>