v0.5 add measure

README.md

@@ -35,4 +35,7 @@ AllInit: Similar to Tester, but run for each possible initial state (2^N of them
 - SqrtNot i
 - SqrtNotDag i
 - SqrtSwap i j (Not implemented yet)
-- Measure i (Measure i time on standard basis, not implemented yet)
+- Measure n
+    + Measures the joint qubit state n times using standard basis
+    + Only works when using Tester
+    + Will end command read

build.gradle.kts

@@ -6,7 +6,7 @@ plugins {
     id("com.github.johnrengelman.shadow") version "6.0.0"
 }
 group = "com.dedztbh"
-version = "0.4"
+version = "0.5"
 
 val ejmlVersion = "0.39"
 

example.txt

@@ -1,16 +1,2 @@
 Hadamard 2
-CNot 1 2
-TDag 2
-CNot 0 2
-T 2
-CNot 1 2
-TDag 2
-CNot 0 2
-TDag 1
-T 2
-CNot 0 1
-Hadamard 2
-TDag 1
-CNot 0 1
-T 0
-S 1
+Measure 10

src/main/kotlin/operator/TFinder.kt

@@ -86,7 +86,10 @@ open class TFinder(val N: Int) : Operator {
 //            "SqrtSwap" -> {
 //                TODO: Implement SqrtSwap
 //            }
-            else -> return -1
+            else -> {
+                System.err.println("Unknown command \"$cmd\". Stop reading commands.")
+                return -1
+            }
         }
         opMatrix = newOp * opMatrix
         return 0

src/main/kotlin/operator/Tester.kt

@@ -1,7 +1,11 @@
 package operator
 
+import org.ejml.data.Complex_F64
 import util.Matrix
+import util.readInt
 import util.times
+import util.upperBound
+import kotlin.random.Random
 
 /**
  * Created by DEDZTBH on 2020/09/22.
@@ -12,6 +16,32 @@ class Tester(N: Int) : TFinder(N) {
     val jointState =
         Matrix(jointStateSize, 1).apply { set(0, 0, 1.0, 0.0) }
 
+    override fun runCmd(cmd: String): Int {
+        if (cmd == "Measure") {
+            val i = readInt()
+            val results = opMatrix * jointState
+            val probs = mutableListOf(0.0)
+            val labels = mutableListOf<Int>()
+            val a = Complex_F64()
+            for (j in 0 until results.numRows) {
+                results.get(0, j, a)
+                if (a.magnitude2 > 0) {
+                    labels.add(j)
+                    probs.add(a.magnitude2 + probs.last())
+                }
+            }
+            println("Measurement(s):")
+            repeat(i) {
+                val r = Random.nextDouble()
+                val index = probs.upperBound(r)
+                println("|${labels[index].toString(2).run { padStart(N - length + 1, '0') }}>")
+            }
+            println()
+            return 1
+        }
+        return super.runCmd(cmd)
+    }
+
     override fun printResult() {
         super.printResult()
         println("\nFinal state: ")

src/main/kotlin/util/algo.kt

@@ -0,0 +1,20 @@
+package util
+
+/**
+ * Created by DEDZTBH on 2020/09/22.
+ * Project KuantumCircuitSim
+ */
+
+fun <T : Comparable<T>> List<T>.upperBound(key: T): Int {
+    var low = 0
+    var high = size - 1
+    while (low < high) {
+        val mid = low + (high - low + 1) / 2
+        if (this[mid] <= key) {
+            low = mid
+        } else {
+            high = mid - 1
+        }
+    }
+    return low
+}