Data commit

Task/Numerical-integration/Kotlin/numerical-integration.kotlin

@@ -0,0 +1,26 @@
+// version 1.1.2
+
+typealias Func = (Double) -> Double
+
+fun integrate(a: Double, b: Double, n: Int, f: Func) {
+    val h = (b - a) / n
+    val sum = DoubleArray(5)
+    for (i in 0 until n) {
+        val x = a + i * h
+        sum[0] += f(x)
+        sum[1] += f(x + h / 2.0)
+        sum[2] += f(x + h)
+        sum[3] += (f(x) + f(x + h)) / 2.0
+        sum[4] += (f(x) + 4.0 * f(x + h / 2.0) + f(x + h)) / 6.0
+    }
+    val methods = listOf("LeftRect ", "MidRect  ", "RightRect", "Trapezium", "Simpson  ")
+    for (i in 0..4) println("${methods[i]} = ${"%f".format(sum[i] * h)}")
+    println()
+}
+
+fun main(args: Array<String>) {
+    integrate(0.0, 1.0, 100) { it * it * it }
+    integrate(1.0, 100.0, 1_000) { 1.0 / it }
+    integrate(0.0, 5000.0, 5_000_000) { it }
+    integrate(0.0, 6000.0, 6_000_000) { it }
+}