Euler method in js

contents/forward_euler_method/code/javascript/euler.js

@@ -0,0 +1,35 @@
+function solveEuler(timeStep, n){
+  const result = [];
+  if (n != 0) {
+    result[0] = 1;
+    for (let i = 1; i < n; ++i) {
+      result[i] = result[i-1] - 3 * result[i-1] * timeStep;
+    }
+  } 
+  return result;
+}
+
+function checkResult(result, threshold, timeStep) {
+  let approx = true;
+  for (let i = 0; i < result.length; ++i) {
+    const solution = Math.exp(-3 * i * timeStep);
+    if (Math.abs(result[i] - solution) > threshold) {
+      console.log(result[i] + " " + solution);
+      approx = false;
+    }
+  }
+  return approx;
+}
+
+const timeStep = 0.01;
+const n = 100;
+const threshold = 0.01;
+
+const result = solveEuler(timeStep, n)
+const approx = checkResult(result, threshold, timeStep)
+
+if (approx) {
+  console.log("All values within threshold");
+} else {
+  console.log("Value(s) not in threshold");
+}

contents/forward_euler_method/forward_euler_method.md

@@ -126,6 +126,8 @@ Full code for the visualization follows:
 [import, lang:"fortran"](code/fortran/euler.f90)
 {% sample lang="go" %}
 [import, lang:"go"](code/golang/euler.go)
+{% sample lang="js" %}
+[import, lang:"javascript"](code/javascript/euler.js)
 {% endmethod %}
 
 <script>