Time constrained simplificaiton

Sources/AngouriMath/AngouriMath/Core/Multithreading/MultithreadingFunctional.cs

@@ -23,7 +23,13 @@ internal static void ExitIfCancelled()
         {
             var token = globalCancellationToken.Value;
             if (token is { } tok)
-                tok.ThrowIfCancellationRequested();
+            {
+                if (tok.IsCancellationRequested)
+                {
+                    globalCancellationToken.Value = null;
+                    throw new System.OperationCanceledException();
+                }
+            }
         }
     }
 }

Sources/AngouriMath/AngouriMath/Functions/Continuous/Solvers/EquationSolver.cs

@@ -82,7 +82,12 @@ internal static List<List<Entity>> InSolveSystem(List<Entity> equations, ReadOnl
                        : new();
             var result = new List<List<Entity>>();
             var replacements = new Dictionary<Variable, Entity>();
+            equations = 
+                equations
+                .Select(eq => eq.SimplifyTimeConstrained(msLimit: 500) ?? eq.InnerSimplified)
+                .ToList();
             for (int i = 0; i < equations.Count; i++)
+            {
                 if (equations[i].ContainsNode(var))
                 {
                     var solutionsOverVar = equations[i].SolveEquation(var).InnerSimplified;
@@ -101,6 +106,7 @@ internal static List<List<Entity>> InSolveSystem(List<Entity> equations, ReadOnl
                         }
                     break;
                 }
+            }
             return result;
         }
     }

Sources/AngouriMath/AngouriMath/Functions/Evaluation/Evaluation.Definition.cs

@@ -212,6 +212,63 @@ public Entity Factorize(int level = 2) => level <= 1
         /// </example>
         public Entity Simplify(int level = 2) => Simplificator.Simplify(this, level);
 
+        /// <summary>
+        /// Simplifies an equation ( e.g. (x - y) * (x + y) -> x^2 - y^2, but 3 * x + y * x = (3 + y) * x )
+        /// with a time constraint.
+        /// </summary>
+        /// <param name="level">
+        /// Increase this argument if you think the equation should be simplified better
+        /// </param>
+        /// <param name="msLimit">
+        /// Specifies the budget time. If simplication takes longer, it will automatically
+        /// stop and return null.
+        /// </param>
+        /// <example>
+        /// <code>
+        /// using System;
+        /// using static AngouriMath.MathS;
+        /// 
+        /// var (x, y, a) = Var("x", "y", "a");
+        /// var expr = Sin(x) + y + a;
+        /// Console.WriteLine(expr);
+        /// Console.WriteLine(expr.Simplify());
+        /// Console.WriteLine("---------------------");
+        /// var expr1 = Sin(x - 3) / Tan(x - 3) + Sec(Sqrt(y)) * Cosec(Sqrt(y));
+        /// Console.WriteLine(expr1);
+        /// Console.WriteLine(expr1.Simplify());
+        /// Console.WriteLine("---------------------");
+        /// var expr2 = Sin(pi / 3) * 2;
+        /// Console.WriteLine(expr2);
+        /// Console.WriteLine(expr2.Simplify());
+        /// Console.WriteLine("---------------------");
+        /// var expr3 = (Pow(x, 3) + 3 * Sqr(x) * y + 3 * x * Sqr(y) + Pow(y, 3)) / (x + y);
+        /// Console.WriteLine(expr3);
+        /// Console.WriteLine(expr3.Simplify());
+        /// Console.WriteLine("---------------------");
+        /// var expr4 = Derivative(Sin(Sqr(x * y) + y * x), x);
+        /// Console.WriteLine(expr4);
+        /// Console.WriteLine(expr4.Simplify());
+        /// </code>
+        /// Prints
+        /// <code>
+        /// sin(x) + y + a
+        /// sin(x) + a + y
+        /// ---------------------
+        /// sin(x - 3) / tan(x - 3) + sec(sqrt(y)) * csc(sqrt(y))
+        /// 2 * csc(2 * sqrt(y)) + cos(x - 3)
+        /// ---------------------
+        /// sin(pi / 3) * 2
+        /// sqrt(3)
+        /// ---------------------
+        /// (x ^ 3 + 3 * x ^ 2 * y + 3 * x * y ^ 2 + y ^ 3) / (x + y)
+        /// x ^ 2 + 2 * x * y + y ^ 2
+        /// ---------------------
+        /// derivative(sin((x * y) ^ 2 + y * x), x)
+        /// cos((x * y) ^ 2 + x * y) * (2 * x * y ^ 2 + y)
+        /// </code>
+        /// </example>
+        public Entity? SimplifyTimeConstrained(int msLimit = 1000, int level = 2) => Simplificator.SimplifyTimeConstrained(this, level, msLimit);
+
         /// <summary>Finds all alternative forms of an expression sorted by their complexity</summary>
         /// <example>
         /// <code>

Sources/AngouriMath/AngouriMath/Functions/Simplification/Simplificator.cs

@@ -8,6 +8,7 @@
 using System;
 using AngouriMath.Core.Multithreading;
 using PeterO.Numbers;
+using System.Threading;
 
 namespace AngouriMath.Functions
 {
@@ -22,6 +23,24 @@ internal static Entity PickSimplest(Entity one, Entity another)
         /// <summary>See more details in <see cref="Entity.Simplify(int)"/></summary>
         internal static Entity Simplify(Entity expr, int level) => Alternate(expr, level).First().InnerSimplified;
 
+        internal static Entity? SimplifyTimeConstrained(Entity expr, int level, int msCount)
+        {
+            var cancellationTokenSource = new CancellationTokenSource();
+            cancellationTokenSource.CancelAfter(msCount);
+            MathS.Multithreading.SetLocalCancellationToken(
+                cancellationTokenSource.Token);
+            try
+            {
+                var res = Simplify(expr, level);
+                MathS.Multithreading.SetLocalCancellationToken(CancellationToken.None);
+                return res;
+            }
+            catch (OperationCanceledException)
+            {
+                return null;
+            }
+        }
+
         internal static Entity SimplifyChildren(Entity expr)
         {
             return expr.Replace(Patterns.InvertNegativePowers)

Sources/Samples/Samples/Playground.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net7.0</TargetFramework>
     <LangVersion>preview</LangVersion>
     <Nullable>enable</Nullable>
   </PropertyGroup>

Sources/Samples/Samples/Program.cs

@@ -8,13 +8,12 @@
 using System;
 using AngouriMath.Core;
 using static AngouriMath.MathS;
+using AngouriMath;
 
-var expr = Sqrt(-1);
-Console.WriteLine(expr);
-Console.WriteLine(expr.Codomain);
-Console.WriteLine(expr.Evaled);
-Console.WriteLine("------------------------------------");
-var newExpr = expr.WithCodomain(Domain.Real);
-Console.WriteLine(newExpr);
-Console.WriteLine(newExpr.Codomain);
-Console.WriteLine(newExpr.Evaled);
+var system = MathS.Equations(
+            "2 * x_1 * (-66) - 6 * x_2 + 24 * x_3 - 12 * x_4 + 270",
+            "-6 * x_1 - 2 * x_2 * 74 - 8 * x_3 + 4 * x_4 - 440",
+            "24 * x_1 - 8 * x_2 - 2 * x_3 * 59 - 16 * x_4 - 190",
+            "-12 * x_1 + 4 * x_2 - 16 * x_3 - 2 * x_4 * 71 + 20"
+            );
+Console.WriteLine(system.Solve("x_1", "x_2", "x_3", "x_4"));

Sources/Tests/UnitTests/Algebra/SolveTest/SolveSystem.cs

@@ -102,5 +102,13 @@ public void EquationWithDivisionIsSolved() => AssertSystemSolvable(new Entity[]
             "x2 + y",
             "y - x - 3"
         }, new Entity.Variable[] { "x", "y" }, 2);
+
+        [Fact]
+        public void EquationLinear() => AssertSystemSolvable(new Entity [] {
+            "2 * x_1 * (-66) - 6 * x_2 + 24 * x_3 - 12 * x_4 + 270",
+            "-6 * x_1 - 2 * x_2 * 74 - 8 * x_3 + 4 * x_4 - 440",
+            "24 * x_1 - 8 * x_2 - 2 * x_3 * 59 - 16 * x_4 - 190",
+            "-12 * x_1 + 4 * x_2 - 16 * x_3 - 2 * x_4 * 71 + 20"
+        }, new Entity.Variable[] { "x", "y" }, 1);
     }
 }

Sources/Tests/UnitTests/UnitTests.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net7.0</TargetFramework>
 
     <IsPackable>false</IsPackable>
     <Platforms>AnyCPU;x64</Platforms>