From 461ba62f7dd75e947769cd4a147136b4f6baac55 Mon Sep 17 00:00:00 2001 From: axexlck Date: Fri, 15 Mar 2024 19:07:54 +0100 Subject: [PATCH] refactor ProductLog - avoid StackOverflow because of recursion - introduce new EvalEngine#evalNumericFunction() method --- .../core/builtin/SpecialFunctions.java | 43 +++++++++++++++++++ .../org/matheclipse/core/eval/EvalEngine.java | 28 ++++++++++-- .../system/rules/ProductLogRules.java | 7 +-- symja_android_library/rules/ProductLogRules.m | 10 +---- 4 files changed, 70 insertions(+), 18 deletions(-) diff --git a/symja_android_library/matheclipse-core/src/main/java/org/matheclipse/core/builtin/SpecialFunctions.java b/symja_android_library/matheclipse-core/src/main/java/org/matheclipse/core/builtin/SpecialFunctions.java index f1f48ea4ca..83041b2dda 100644 --- a/symja_android_library/matheclipse-core/src/main/java/org/matheclipse/core/builtin/SpecialFunctions.java +++ b/symja_android_library/matheclipse-core/src/main/java/org/matheclipse/core/builtin/SpecialFunctions.java @@ -2120,12 +2120,55 @@ public void setUp(final ISymbol newSymbol) { @Override public IExpr e1ObjArg(final IExpr o) { + IExpr temp = functionExpandLogArg(o); + if (temp.isPresent()) { + return temp; + } if (o.equals(F.C0) || o.equals(F.CD0)) { return F.C0; } return F.NIL; } + private static IExpr functionExpandLogArg(final IExpr o) { + if (o.isTimes() && o.first().isFraction() && o.argSize() == 3) { + // ProductLog(Rational(k_,n_)*b_^Rational(c_,n_)*Log(b_)) := + // Module( {a, v}, + // a = N( (n*ProductLog((b^(c/n)*k*Log(b))/n))/Log(b) ); + // v = Rationalize(a); + // v*Log(b)/n + // /; IntegerQ(v) && v >= 1 && PossibleZeroQ( (((-b^(c/n))*k + b^(v/n)*v)*Log(b))/n )) + IAST times = (IAST) o; + if (times.arg2().isPower() && times.arg3().isLog()) { + IAST power = (IAST) times.arg2(); + if (power.base().isInteger() && power.base().equals(times.arg3().first()) + && power.exponent().isFraction()) { + IInteger b = (IInteger) times.arg3().first(); + IFraction arg1 = (IFraction) times.arg1(); + IInteger k = arg1.numerator(); + IInteger n = arg1.denominator(); + IFraction powExponent = (IFraction) power.exponent(); + if (n.equals(powExponent.denominator())) { + EvalEngine engine = EvalEngine.get(); + IExpr a = engine + .evalNumericFunction(F.Times(n, F.ProductLog(F.Times(arg1, F.Power(b, powExponent), F.Log(b))), + F.Power(F.Log(b), F.CN1))); + IExpr v = engine.evaluate(F.Rationalize(a)); + if (v.isInteger() && ((IInteger) v).isGE(F.C1)) { + IFraction resultFactor = F.QQ((IInteger) v, n); + IExpr isZero = engine.evaluate(F.Plus(F.Times(k.negate(), F.Power(b, powExponent)), + F.Times(v, F.Power(b, resultFactor)))); + if (isZero.isZero()) { + return engine.evaluate(F.Times(resultFactor, F.Log(b))); + } + } + } + } + } + } + return F.NIL; + } + @Override public IExpr e2ObjArg(IExpr k, IExpr z) { int ki = Integer.MIN_VALUE; diff --git a/symja_android_library/matheclipse-core/src/main/java/org/matheclipse/core/eval/EvalEngine.java b/symja_android_library/matheclipse-core/src/main/java/org/matheclipse/core/eval/EvalEngine.java index a06c749eea..3701127c85 100644 --- a/symja_android_library/matheclipse-core/src/main/java/org/matheclipse/core/eval/EvalEngine.java +++ b/symja_android_library/matheclipse-core/src/main/java/org/matheclipse/core/eval/EvalEngine.java @@ -787,8 +787,8 @@ private IAST endTrace() { * * @param result0 store the result of the evaluation in the i-th argument of the ast in * result0[0]. result0[0] should be F.NIL if no evaluation - * occured. - * @param ast the original ast for whixh the arguments should be evaluated + * occurred. + * @param ast the original ast for which the arguments should be evaluated * @param arg the i-th argument of ast * @param i arg is the i-th argument of ast * @param isNumericFunction if true the NumericFunction attribute is set @@ -1671,14 +1671,14 @@ public final int evalInt(final IExpr expr) throws ArgumentTypeException { result = expr.toIntDefault(); } if (expr.isNumericFunction(true)) { - IExpr numericResult = evalN(expr); + IExpr numericResult = evalNumericFunction(expr); if (numericResult.isReal()) { result = numericResult.toIntDefault(); } } else { IExpr temp = evaluateNIL(expr); if (temp.isNumericFunction(true)) { - IExpr numericResult = evalN(temp); + IExpr numericResult = evalNumericFunction(temp); if (numericResult.isReal()) { result = numericResult.toIntDefault(); } @@ -2093,6 +2093,26 @@ private void printOnOffTrace(IExpr unevaledExpr, IExpr evaledExpr) { } } + public final IExpr evalNumericFunction(final IExpr expr) { + if (expr.isNumericFunction(true)) { + final boolean oldNumericMode = isNumericMode(); + final long oldDigitPrecision = getNumericPrecision(); + final int oldSignificantFigures = getSignificantFigures(); + try { + setNumericMode(true, oldDigitPrecision, oldSignificantFigures); + IExpr temp = evalWithoutNumericReset(expr); + if (temp.isListOrAssociation() || temp.isRuleAST()) { + return ((IAST) temp).mapThread(arg -> evalNumericFunction(arg)); + } + return temp; + } finally { + setNumericMode(oldNumericMode); + setNumericPrecision(oldDigitPrecision); + } + } + return expr; + } + /** * Evaluates expr numerically. * diff --git a/symja_android_library/matheclipse-core/src/main/java/org/matheclipse/core/reflection/system/rules/ProductLogRules.java b/symja_android_library/matheclipse-core/src/main/java/org/matheclipse/core/reflection/system/rules/ProductLogRules.java index 514dcd0fda..1f06a56f6c 100644 --- a/symja_android_library/matheclipse-core/src/main/java/org/matheclipse/core/reflection/system/rules/ProductLogRules.java +++ b/symja_android_library/matheclipse-core/src/main/java/org/matheclipse/core/reflection/system/rules/ProductLogRules.java @@ -13,7 +13,7 @@ public class ProductLogRules { *
  • index 0 - number of equal rules in RULES
    • * */ - final public static int[] SIZES = { 12, 5 }; + final public static int[] SIZES = { 12, 4 }; final public static IAST RULES = List( IInit(ProductLog, SIZES), @@ -64,9 +64,6 @@ public class ProductLogRules { Condition(x,GreaterEqual(x,CN1))), // ProductLog(-1,E^x_*x_):=x/;x<=-1 ISetDelayed(ProductLog(CN1,Times(Exp(x_),x_)), - Condition(x,LessEqual(x,CN1))), - // ProductLog(Log(b_)*k_/n_*b_^(c_/n_)):=Module({a,v},a=N((n*ProductLog((b^(c/n)*k*Log(b))/n))/Log(b));v=Rationalize(a);v*Log(b)/n/;IntegerQ(v)&&v>=1&&PossibleZeroQ(((-b^(c/n)*k+b^(v/n)*v)*Log(b))/n)) - ISetDelayed(ProductLog(Times(Log(b_),Rational(k_,n_),Power(b_,Rational(c_,n_)))), - Module(list(a,v),CompoundExpression(Set(a,N(Times(n,Power(Log(b),CN1),ProductLog(Times(Power(b,Times(c,Power(n,CN1))),k,Power(n,CN1),Log(b)))))),Set(v,Rationalize(a)),Condition(Times(v,Power(n,CN1),Log(b)),And(IntegerQ(v),GreaterEqual(v,C1),PossibleZeroQ(Times(Power(n,CN1),Plus(Times(CN1,Power(b,Times(c,Power(n,CN1))),k),Times(Power(b,Times(Power(n,CN1),v)),v)),Log(b)))))))) + Condition(x,LessEqual(x,CN1))) ); } diff --git a/symja_android_library/rules/ProductLogRules.m b/symja_android_library/rules/ProductLogRules.m index bbae6b9116..6c914782f4 100644 --- a/symja_android_library/rules/ProductLogRules.m +++ b/symja_android_library/rules/ProductLogRules.m @@ -21,13 +21,5 @@ ProductLog(x_*E^x_) := x /; x>=-1, ProductLog(-1, x_*E^x_) := x - /; x<=-1, -ProductLog(Rational(k_,n_)*b_^Rational(c_,n_)*Log(b_)) := - Module( {a, v}, - a = N( (n*ProductLog((b^(c/n)*k*Log(b))/n))/Log(b) ); - v = Rationalize(a); - v*Log(b)/n - /; IntegerQ(v) && - v >= 1 && - PossibleZeroQ( (((-b^(c/n))*k + b^(v/n)*v)*Log(b))/n )) + /; x<=-1 } \ No newline at end of file