WIP #947: Factor: check if degree is <= Config.MAX_POLYNOMIAL_DEGREE

Author: axkr

symja_android_library/matheclipse-core/src/main/java/org/matheclipse/core/builtin/Algebra.java

@@ -5214,11 +5214,11 @@ private static IExpr factorComplex(IExpr expr, List<IExpr> varList, ISymbol head
         ComplexRing<BigRational> cfac = new ComplexRing<BigRational>(BigRational.ZERO);
         JASConvert<Complex<BigRational>> jas = new JASConvert<Complex<BigRational>>(varList, cfac);
         GenPolynomial<Complex<BigRational>> polyRat = jas.expr2JAS(expr, numeric2Rational);
-        return factorComplex(expr, polyRat, jas, head, cfac).eval(engine);
+        return factorComplex(polyRat, jas, head, cfac, expr).eval(engine);
       } else {
         JASConvert<BigRational> jas = new JASConvert<BigRational>(varList, BigRational.ZERO);
         GenPolynomial<BigRational> polyRat = jas.expr2JAS(expr, numeric2Rational);
-        return factorRational(polyRat, jas, head, expr);
+        return factorRational(polyRat, jas, head);
       }
     } catch (RuntimeException rex) {
       LOGGER.debug("Algebra.factorComplex() failed", rex);
@@ -5237,10 +5237,16 @@ public static IExpr factor(IExpr arg1, EvalEngine engine) {
    * @param head the head of the factorization result AST (typically <code>F.Times</code> or <code>
    *     F.List</code>)
    * @param cfac
+   * @param original the original expression
    * @return
    */
-  private static IExpr factorComplex(IExpr expr, GenPolynomial<Complex<BigRational>> polynomial,
-      JASConvert<? extends RingElem<?>> jas, ISymbol head, ComplexRing<BigRational> cfac) {
+  private static IExpr factorComplex(GenPolynomial<Complex<BigRational>> polynomial,
+      JASConvert<? extends RingElem<?>> jas, ISymbol head, ComplexRing<BigRational> cfac,
+      IExpr original) {
+    if (polynomial.degree() > Config.MAX_POLYNOMIAL_DEGREE) {
+      // Exponent ist out of bounds for function `1`.
+      return Errors.printMessage(S.Factor, "lrgexp", F.List(S.Factor));
+    }
     FactorComplex<BigRational> factorAbstract = new FactorComplex<BigRational>(cfac);
     SortedMap<GenPolynomial<Complex<BigRational>>, Long> map = factorAbstract.factors(polynomial);
 
@@ -5253,7 +5259,7 @@ private static IExpr factorComplex(IExpr expr, GenPolynomial<Complex<BigRational
       if (entry.getValue().equals(1L) && map.size() <= 2
           && (key.equals(F.CNI) || key.equals(F.CI))) {
         // hack: factoring -I and I out of an expression should give no new factorized expression
-        return expr;
+        return original;
       }
       result.append(F.Power(jas.complexPoly2Expr(entry.getKey()), F.ZZ(entry.getValue())));
     }
@@ -5307,7 +5313,11 @@ public static IAST factorModulus(JASModInteger jas, ModLongRing modIntegerRing,
   }
 
   public static IAST factorRational(GenPolynomial<BigRational> polyRat, JASConvert<BigRational> jas,
-      ISymbol head, IExpr original) {
+      ISymbol head) {
+    if (polyRat.degree() > Config.MAX_POLYNOMIAL_DEGREE) {
+      // Exponent ist out of bounds for function `1`.
+      return Errors.printMessage(S.Factor, "lrgexp", F.List(S.Factor));
+    }
     Object[] objects = jas.factorTerms(polyRat);
     GenPolynomial<edu.jas.arith.BigInteger> poly =
         (GenPolynomial<edu.jas.arith.BigInteger>) objects[2];

symja_android_library/matheclipse-core/src/main/java/org/matheclipse/core/builtin/RootsFunctions.java

@@ -917,7 +917,7 @@ public static IAST rootsOfVariable(final IExpr expr, final IExpr denominator,
       }
       // }
       IASTAppendable newResult = F.ListAlloc(8);
-      IAST factorRational = Algebra.factorRational(polyRat, jas, S.List, null);
+      IAST factorRational = Algebra.factorRational(polyRat, jas, S.List);
       if (factorRational.isNIL()) {
         factorRational = F.Times(expr);
       }
@@ -936,7 +936,7 @@ public static IAST rootsOfVariable(final IExpr expr, final IExpr denominator,
           }
         } else {
           polyRat = jas.expr2JAS(temp, numericSolutions);
-          IAST factorComplex = Algebra.factorRational(polyRat, jas, S.List, null);
+          IAST factorComplex = Algebra.factorRational(polyRat, jas, S.List);
           if (factorComplex.isNIL()) {
             factorComplex = F.Times(expr);
           }

symja_android_library/matheclipse-core/src/main/java/org/matheclipse/core/eval/Errors.java

@@ -186,6 +186,7 @@ public static void initGeneralMessages() {
       "locked", "Symbol `1` is locked.", //
       "lowlen", "Required length `1` is smaller than maximum `2` of support of `3`.", //
       "lpsnf", "No solution can be found that satisfies the constraints.", //
+      "lrgexp", "Exponent ist out of bounds for function `1`.", //
       "lslc", "Coefficient matrix and target vector or matrix do not have the same dimensions.", //
       "lstpat", "List or pattern matching a list expected at position `1` in `2`.", //
       "lvlist", "Local variable specification `1` is not a List.", //

symja_android_library/matheclipse-core/src/test/java/org/matheclipse/core/system/ExprEvaluatorTestCase.java

@@ -253,7 +253,7 @@ public void setUp() {
       Config.MAX_AST_SIZE = 20000;
       Config.MAX_MATRIX_DIMENSION_SIZE = 100;
       Config.MAX_BIT_LENGTH = 200000;
-      Config.MAX_POLYNOMIAL_DEGREE = 100;
+      Config.MAX_POLYNOMIAL_DEGREE = 150;
       Config.FILESYSTEM_ENABLED = false;
       Config.ROUNDING_MODE = RoundingMode.HALF_EVEN;
       // fScriptEngine = fScriptManager.getEngineByExtension("m");

symja_android_library/matheclipse-core/src/test/java/org/matheclipse/core/system/LowercaseTestCase.java

@@ -8627,9 +8627,9 @@ public void testFibonacci() {
     // Fibonacci(11,{13,2,3,a})
     check("Fibonacci(11,{13,2,3,a})", //
         "{145336221161,5741,141481,1+15*a^2+35*a^4+28*a^6+9*a^8+a^10}");
-    // message Polynomial degree 101 exceeded
-    check("Fibonacci(101,11/9223372036854775807)", //
-        "Fibonacci(101,11/9223372036854775807)");
+    // message Polynomial degree 151 exceeded
+    check("Fibonacci(151,11/9223372036854775807)", //
+        "Fibonacci(151,11/9223372036854775807)");
 
     // iter limit
     check("Fibonacci(2147483647)", //
@@ -14485,8 +14485,8 @@ public void testLucasL() {
 
     // slow
     // message Polynomial degree 101 exceeded
-    check("LucasL(101,1/1317624576693539401)", //
-        "LucasL(101,1/1317624576693539401)");
+    check("LucasL(151,1/1317624576693539401)", //
+        "LucasL(151,1/1317624576693539401)");
     check("LucasL(Quantity(1.2,\"m\"),2.718281828459045)", //
         "LucasL(1.2[m],2.71828)");
 

symja_android_library/matheclipse-core/src/test/java/org/matheclipse/core/system/PolynomialFunctionsTest.java

@@ -92,8 +92,8 @@ public void testGegenbauerC() {
 
     // message Polynomial degree 101 exceeded
     check(
-        "GegenbauerC(101,-9223372036854775807/9223372036854775808-I*9223372036854775808/9223372036854775807,z)", //
-        "GegenbauerC(101,-9223372036854775807/9223372036854775808-I*9223372036854775808/\n"
+        "GegenbauerC(151,-9223372036854775807/9223372036854775808-I*9223372036854775808/9223372036854775807,z)", //
+        "GegenbauerC(151,-9223372036854775807/9223372036854775808-I*9223372036854775808/\n"
             + "9223372036854775807,z)");
 
     check("GegenbauerC(3, l, z)", //

symja_android_library/matheclipse-core/src/test/java/org/matheclipse/core/system/SolveTest.java

@@ -789,6 +789,7 @@ public void testSolve() {
         "{{x->-81.08825721072805},{x->81.08825721072805}}");
   }
 
+
   @Test
   public void testNSolve() {
     check("NSolve(2*x^(x-3)==3^(x-2),x)", //
@@ -2065,6 +2066,13 @@ public void testIssue939() {
             + "3)*5^(2/3))/(3*Pi)^(1/3)}}");
   }
 
+  @Test
+  public void testIssue947() {
+    // message: Exponent ist out of bounds for function Factor.
+    check("Solve(2^(1250000/x) == 500, x)", //
+        "{{x->(1250000*Log(2))/Log(500)}}");
+  }
+
   /** The JUnit setup method */
   @Override
   public void setUp() {