fixed narrowing

Author: MaxRev-Dev

BinaryRelations/Binary/UnaryOperations.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Linq;
 using MaxRev.Extensions.Matrix;
 
 namespace MaxRev.Extensions.Binary
@@ -72,24 +73,21 @@ public static partial class BinaryRelations
         /// Narrows matrix to region defined by X1 and X2. Indexes are starting from 1 
         /// </summary>
         /// <param name="matrix1">binary matrix</param>
-        /// <param name="x1">index [1..n]</param>
-        /// <param name="x2">index [1..n]</param>
+        /// <param name="x">index [1..n]</param> 
         /// <returns>binary matrix</returns>
-        public static bool[,] Narrowing(this bool[,] matrix1, int x1, int x2)
+        public static bool[,] Narrowing(this bool[,] matrix1, params int[] x)
         {
-            if (x1 > x2) throw new InvalidOperationException(nameof(x1) + " must be bigger than " + nameof(x2));
+            if (x == null) throw new ArgumentNullException(nameof(x));
             ThrowIfNull_NotQuad(matrix1);
             var length = matrix1.GetLength(0);
             var result = new bool[length, length];
-            x1--;
-            x2--;
+            x = x.Select(p => --p).ToArray();
             for (int i = 0; i < length; i++)
             {
                 for (int j = 0; j < length; j++)
                 {
-                    result[i, j] = i >= x1 && i <= x2
-                               && j <= x2 && j >= x1
-                               && matrix1[i, j];
+                    if (x.Contains(i) || x.Contains(j))
+                        result[i, j] = matrix1[i, j];
                 }
             }
 

BinaryRelations/BinaryRelations.csproj

@@ -3,7 +3,7 @@
   <PropertyGroup>
     <TargetFramework>netstandard2.0</TargetFramework>
     <RootNamespace>MaxRev.Extensions</RootNamespace>
-    <Version>1.1.0</Version>
+    <Version>1.2.0</Version>
     <Authors>MaxRev</Authors>
     <Copyright>MaxRev © 2019</Copyright>
     <Description>Binary relations and matrix extensions library targeting netstandard2.0</Description>

BinaryRelationsTests/BinaryRelationsOperationsTests.cs

@@ -145,19 +145,46 @@ public void Narrowing()
         {
             var m1 = new[,]
             {
+                {1, 1, 1, 1},
+                {1, 1, 1, 1},
+                {1, 1, 1, 1},
+                {1, 1, 1, 1},
+            }.Cast<int, bool>();
+            var expected = new[,]
+            {
+                {1, 1, 1, 1},
                 {1, 0, 0, 1},
-                {1, 1, 1, 0},
-                {0, 1, 0, 1},
+                {1, 0, 0, 1},
+                {1, 1, 1, 1},
+            }.Cast<int, bool>();
+            Assert.Equal(expected, m1.Narrowing(1, 4));
+
+            expected = new[,]
+            {
+                {1, 1, 1, 1},
+                {1, 1, 1, 1},
+                {1, 1, 0, 0},
                 {1, 1, 0, 0},
             }.Cast<int, bool>();
-            var expected = new[,]
+            Assert.Equal(expected, m1.Narrowing(1, 2));
+
+            expected = new[,]
             {
-                {0, 0, 0, 0},
-                {0, 1, 1, 0},
-                {0, 1, 0, 0},
-                {0, 0, 0, 0},
+                {1, 1, 1, 1},
+                {1, 0, 1, 1},
+                {1, 1, 1, 1},
+                {1, 1, 1, 1},
+            }.Cast<int, bool>();
+            Assert.Equal(expected, m1.Narrowing(1, 3, 4));
+
+            expected = new[,]
+            {
+                {1, 1, 1, 1},
+                {1, 0, 0, 0},
+                {1, 0, 0, 0},
+                {1, 0, 0, 0},
             }.Cast<int, bool>();
-            Assert.Equal(expected, m1.Narrowing(2, 3));
+            Assert.Equal(expected, m1.Narrowing(1));
         }
 
         [Fact]