Data commit

Task/Euler-method/Wren/euler-method.wren

@@ -0,0 +1,25 @@
+import "/fmt" for Fmt
+import "/iterate" for Stepped
+
+var euler = Fn.new { |f, y, step, end|
+    Fmt.write(" Step $2d: ", step)
+    for (t in Stepped.new(0..end, step)) {
+        if (t%10 == 0) Fmt.write(" $7.3f", y)
+        y = y + step * f.call(y)
+    }
+    System.print()
+}
+
+var analytic = Fn.new {
+    System.write("    Time: ")
+    for (t in Stepped.new(0..100, 10)) Fmt.write(" $7d", t)
+    System.write("\nAnalytic: ")
+    for (t in Stepped.new(0..100, 10)) {
+        Fmt.write(" $7.3f", 20 + 80 * (-0.07*t).exp)
+    }
+    System.print()
+}
+var cooling = Fn.new { |temp| -0.07 * (temp - 20) }
+
+analytic.call()
+for (i in [2, 5, 10]) euler.call(cooling, 100, i, 100)