unique

Author: Quafadas

vecxt/src/doublearray.scala

@@ -2,11 +2,47 @@ package vecxt
 
 import narr.*
 import vecxt.JsNativeDoubleArrays.*
-
 import arrays.*
 
 object DoubleArrays:
-  // extension (vec: NArray[Double])
+  extension (vec: NArray[Double])
+    inline def unique: NArray[Double] = 
+      if (vec.size == 0) {
+        NArray.empty[Double]
+      } else {        
+        
+        val data = narr.copy[Double](vec)
+        narr.sort(data)()
+        var elementCount = 1
+        var lastElement = data(0)
+
+        var i = 0
+        while (i < data.length) {
+          val di = data(i)
+          if (di != lastElement) {
+            elementCount += 1
+            lastElement = di
+          }
+          i += 1
+        }
+
+        val result = NArray.ofSize[Double](elementCount)
+        result(0) = data(0)
+        lastElement = data(0)
+        var idx = 1
+        i = 0
+        while (i < data.length) {
+          val di = data(i)
+          if (di != lastElement) {
+            result(idx) = di
+            lastElement = di
+            idx += 1
+          }
+          i += 1
+        }
+
+        result
+      }
 
   // inline def lt(num: Double): NArray[Boolean] = vec < num
 

vecxt/test/src/array.test.scala

@@ -33,6 +33,29 @@ class ArrayExtensionSuite extends munit.FunSuite:
     assert(out.contains("5"))
   }
 
+  test("unique") {
+    val v1 = NArray[Double](1, 2, 3, 2, 1, 4)
+    val unique = v1.unique
+    assertEquals(unique.length, 4)
+    assertEquals(unique(0), 1.0)
+    assertEquals(unique(1), 2.0)
+    assertEquals(unique(2), 3.0)
+    assertEquals(unique(3), 4.0)
+
+    val v2 = NArray[Double](1, 1, 1, 1, 1)
+    val unique2 = v2.unique
+    assertEquals(unique2.length, 1)
+
+    val v3 = NArray[Double]()
+    val unique3 = v3.unique
+    assertEquals(unique3.length, 0)
+
+    val v4 = NArray[Double](1, 2, 3, 4, 5)
+    val unique4 = v4.unique 
+    assertEquals(unique4.length, 5)    
+
+  }
+
   test("Array horizontal sum") {
     val v1 = NArray[Double](1.0, 2.0, 3.0)
     val v2 = v1 * 2.0