WIP #914 restrict Solve expressions leafCount()

- restrict Laguerre solver to max. 10000 iterations - factor only expressions with leafs < Config.MAX_SIMPLIFY_FACTOR_LEAFCOUNT / 2 - eliminate one variable expressions with leafs < Config.MAX_SIMPLIFY_FACTOR_LEAFCOUNT / 2
axkr · Feb 26, 2024 · 24905a0 · 24905a0
1 parent 5944c34
commit 24905a0
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Showing 5 changed files with 30 additions and 19 deletions.
diff --git a/...droid_library/matheclipse-core/src/main/java/org/matheclipse/core/builtin/Arithmetic.java b/...droid_library/matheclipse-core/src/main/java/org/matheclipse/core/builtin/Arithmetic.java
@@ -4374,6 +4374,13 @@ private static IExpr e2ObjArg(IAST ast, final IExpr base, final IExpr exponent)
       return F.NIL;
     }
 
+    /**
+     * Evaluate expressions <code>Times(...) ^ exponent</code>.
+     * 
+     * @param baseTimes
+     * @param exponent
+     * @return
+     */
     private static IExpr powerTimesN(IAST baseTimes, final IExpr exponent) {
       // for non-rational exponents
       IASTAppendable filterAST = baseTimes.copyHead();
@@ -4414,6 +4421,13 @@ private static IExpr powerTimesN(IAST baseTimes, final IExpr exponent) {
       return F.NIL;
     }
 
+    /**
+     * Evaluate expressions <code>Times(...) ^ (fractional-number)</code>
+     * 
+     * @param baseTimes
+     * @param exponent
+     * @return
+     */
     private static IExpr powerTimesFraction(IAST baseTimes, final IFraction exponent) {
       IASTAppendable result = F.TimesAlloc(baseTimes.argSize());
       IASTAppendable rest = F.TimesAlloc(baseTimes.argSize());
@@ -4485,14 +4499,14 @@ private static IExpr powerTimesFraction(IAST baseTimes, final IFraction exponent
           result.append(F.Power(rest.oneIdentity1(), exponent));
         }
         if (exponent2Times != null) {
-        for (Map.Entry<IFraction, IASTAppendable> entry : exponent2Times.entrySet()) {
-          IFraction exp = entry.getKey();
-          rest = entry.getValue();
-          if (rest.argSize() > 0) {
-            result.append(F.Power(rest.oneIdentity1(), exp));
+          for (Map.Entry<IFraction, IASTAppendable> entry : exponent2Times.entrySet()) {
+            IFraction exp = entry.getKey();
+            rest = entry.getValue();
+            if (rest.argSize() > 0) {
+              result.append(F.Power(rest.oneIdentity1(), exp));
+            }
           }
         }
-      }
         return result;
       }
       return F.NIL;

diff --git a/...d_library/matheclipse-core/src/main/java/org/matheclipse/core/builtin/RootsFunctions.java b/...d_library/matheclipse-core/src/main/java/org/matheclipse/core/builtin/RootsFunctions.java
@@ -532,11 +532,6 @@ public static IAST roots(final IExpr arg1, boolean numericSolutions, IAST variab
    */
   protected static IAST findRoots(double... coefficients) {
     try {
-      for (int j = 0; j < coefficients.length; j++) {
-        if (!Double.isFinite(coefficients[j])) {
-          return F.NIL;
-        }
-      }
       org.hipparchus.complex.Complex[] complexRoots = allComplexRootsLaguerre(coefficients);
       if (complexRoots == null) {
         return F.NIL;
@@ -1025,7 +1020,7 @@ private static org.hipparchus.complex.Complex[] allComplexRootsLaguerre(
       LaguerreSolver solver = new LaguerreSolver(Config.DEFAULT_ROOTS_CHOP_DELTA);
       // see https://github.com/Hipparchus-Math/hipparchus/issues/177 for initial value
       // https://stackoverflow.com/q/65960318
-      return solver.solveAllComplex(coefficients, 100_000, 1.0);
+      return solver.solveAllComplex(coefficients, 10_000, 1.0);
     } catch (MathRuntimeException mre) {
       // mre.printStackTrace();
       // org.hipparchus.exception.MathIllegalStateException: maximal count (100,000) exceeded

diff --git a/...rary/matheclipse-core/src/main/java/org/matheclipse/core/reflection/system/Eliminate.java b/...rary/matheclipse-core/src/main/java/org/matheclipse/core/reflection/system/Eliminate.java
@@ -382,7 +382,7 @@ private static IExpr extractVariableRecursive(IExpr exprWithVariable, IExpr expr
         }
       } else {
         int size = ast.size();
-        if (size > 2) {
+        if (size > 2 && ast.leafCount() < Config.MAX_SIMPLIFY_FACTOR_LEAFCOUNT / 2) {
           if (exprWithoutVariable.isZero() && ast.isPlus()) {
             IAST elimZeroPlus = F.binaryAST2(elimzeroplus, ast, variable);
             IExpr result = zeroPlusMatcher().apply(elimZeroPlus);

diff --git a/..._library/matheclipse-core/src/main/java/org/matheclipse/core/reflection/system/Solve.java b/..._library/matheclipse-core/src/main/java/org/matheclipse/core/reflection/system/Solve.java
@@ -970,10 +970,12 @@ private IASTMutable solveTimesEquationsRecursively(IASTMutable termsEqualZero,
                   }
                 }
               }
-              termEQZero = S.Factor.of(engine, termEQZero);
-              if (termEQZero.isTimes()) {
-                solveTimesAST((IAST) termEQZero, termsEqualZero, inequationsList, numericFlag,
-                    variables, multipleValues, engine, subSolutionSet, i);
+              if (termEQZero.leafCount() < Config.MAX_SIMPLIFY_FACTOR_LEAFCOUNT / 2) {
+                termEQZero = S.Factor.of(engine, termEQZero);
+                if (termEQZero.isTimes()) {
+                  solveTimesAST((IAST) termEQZero, termsEqualZero, inequationsList, numericFlag,
+                      variables, multipleValues, engine, subSolutionSet, i);
+                }
               }
             }
           }

diff --git a/...android_library/matheclipse-core/src/test/java/org/matheclipse/core/system/SolveTest.java b/...android_library/matheclipse-core/src/test/java/org/matheclipse/core/system/SolveTest.java
@@ -2010,8 +2010,8 @@ public void testIssue902() {
   @Test
   public void testIssue914() {
     // TODO
-    // check("Solve(5==35500*(1+x/4)^(4*7),x)", //
-    // "");
+    check("Solve(5==35500*(1+x/4)^(4*7),x)", //
+        "Solve((1+x/4)^28==1/7100,x)");
     check("Solve({A==20^300,A==26158/5},{A})", //
         "{}");
   }