70 lines
1.4 KiB
Plaintext
70 lines
1.4 KiB
Plaintext
// version 1.2.0
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import kotlin.math.*
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typealias Function = (Double) -> Double
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/**
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* Integrates input function K over time
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* S + (t1 - t0) * (K(t1) + K(t0)) / 2
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*/
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class Integrator {
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private val start: Long
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private @Volatile var running = false
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private lateinit var func: Function
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private var t0 = 0.0
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private var v0 = 0.0
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private var sum = 0.0
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constructor(func: Function) {
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start = System.nanoTime()
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setFunc(func)
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Thread(this::integrate).start()
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}
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fun setFunc(func: Function) {
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this.func = func
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v0 = func(0.0)
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t0 = 0.0
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}
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fun getOutput() = sum
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fun stop() {
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running = false
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}
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private fun integrate() {
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running = true
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while (running) {
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try {
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Thread.sleep(1)
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update()
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}
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catch(e: InterruptedException) {
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return
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}
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}
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}
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private fun update() {
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val t1 = (System.nanoTime() - start) / 1.0e9
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val v1 = func(t1)
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val rect = (t1 - t0) * (v0 + v1) / 2.0
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sum += rect
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t0 = t1
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v0 = v1
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}
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}
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fun main(args: Array<String>) {
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val integrator = Integrator( { sin(PI * it) } )
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Thread.sleep(2000)
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integrator.setFunc( { 0.0 } )
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Thread.sleep(500)
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integrator.stop()
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println(integrator.getOutput())
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}
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