Data commit

Task/Feigenbaum-constant-calculation/Scala/feigenbaum-constant-calculation-1.scala

@@ -0,0 +1,25 @@
+object Feigenbaum1 extends App {
+  val (max_it, max_it_j) = (13, 10)
+  var (a1, a2, d1, a) = (1.0, 0.0, 3.2, 0.0)
+
+  println(" i       d")
+  var i: Int = 2
+  while (i <= max_it) {
+    a = a1 + (a1 - a2) / d1
+    for (_ <- 0 until max_it_j) {
+      var (x, y) = (0.0, 0.0)
+      for (_ <- 0 until 1 << i) {
+        y = 1.0 - 2.0 * y * x
+        x = a - x * x
+      }
+      a -= x / y
+    }
+    val d: Double = (a1 - a2) / (a - a1)
+    printf("%2d    %.8f\n", i, d)
+    d1 = d
+    a2 = a1
+    a1 = a
+    i += 1
+  }
+
+}

Task/Feigenbaum-constant-calculation/Scala/feigenbaum-constant-calculation-2.scala

@@ -0,0 +1,34 @@
+object Feigenbaum2 extends App {
+  private val (max_it, max_it_j) = (13, 10)
+
+  private def result = {
+
+    @scala.annotation.tailrec
+    def outer(i: Int, d1: Double, a2: Double, a1: Double, acc: Seq[Double]): Seq[Double] = {
+      @scala.annotation.tailrec
+      def center(j: Int, a: Double): Double = {
+        @scala.annotation.tailrec
+        def inner(k: Int, end: Int, x: Double, y: Double): (Double, Double) =
+          if (k < end) inner(k + 1, end, a - x * x, 1.0 - 2.0 * y * x) else (x, y)
+
+        val (x, y) = inner(0, 1 << i, 0.0, 0.0)
+        if (j < max_it_j) {
+          center(j + 1, a - (x / y))
+        } else a
+      }
+
+      if (i <= max_it) {
+        val a = center(0, a1 + (a1 - a2) / d1)
+        val d: Double = (a1 - a2) / (a - a1)
+
+        outer(i + 1, d, a1, a, acc :+ d)
+      } else acc
+    }
+
+    outer(2, 3.2, 0, 1.0, Seq[Double]()).zipWithIndex
+  }
+
+  println(" i     ≈ δ")
+  result.foreach { case (δ, i) => println(f"${i + 2}%2d  $δ%.8f") }
+
+}