/// <summary>
/// Check for inequality.
/// </summary>
/// <param name="b">The other operand.</param>
/// <returns>
/// A value representing true if not equal.
/// </returns>
public override Derivatives <Expression> NotEqual(Derivatives <Expression> b)
{
var result = new ExpressionTreeDerivatives();
result[0] = Expression.Condition(Expression.NotEqual(this[0], b[0]), One, Zero);
return(result);
}
/// <summary>
/// Subtract derivatives.
/// </summary>
/// <param name="b">The other operand.</param>
/// <returns>
/// The difference.
/// </returns>
public override Derivatives <Expression> Subtract(Derivatives <Expression> b)
{
var size = Math.Max(Count, b.Count);
var result = new ExpressionTreeDerivatives(size);
for (var i = 0; i < size; i++)
{
if (this[i] == null)
{
if (b[i] == null)
{
result[i] = null;
}
else
{
result[i] = Expression.Negate(b[i]);
}
}
else
{
if (b[i] == null)
{
result[i] = this[i];
}
else
{
result[i] = Expression.Subtract(this[i], b[i]);
}
}
}
return(result);
}
/// <summary>
/// Multiply derivatives.
/// </summary>
/// <param name="b">The other operand.</param>
/// <returns>
/// The multiplied result.
/// </returns>
public override Derivatives <Func <double> > Multiply(Derivatives <Func <double> > b)
{
var size = Math.Max(Count, b.Count);
var result = new DoubleDerivatives(size);
var a0 = this[0];
var b0 = b[0];
result[0] = () => a0() * b0();
for (var i = 1; i < size; i++)
{
var arg1 = this[i];
var arg2 = b[i];
if (arg1 != null && arg2 != null)
{
result[i] = () => b0() * arg1() + arg2() * a0();
}
else if (arg1 != null)
{
result[i] = () => arg1() * b0();
}
else if (arg2 != null)
{
result[i] = () => a0() * arg2();
}
}
return(result);
}
/// <summary>
/// Nots the equal.
/// </summary>
/// <param name="other">The other.</param>
/// <returns></returns>
public override Derivatives <Func <double> > NotEqual(Derivatives <Func <double> > other)
{
var result = new DoubleDerivatives();
var arg1 = this[0];
var arg2 = other[0];
result[0] = () => arg1().Equals(arg2()) ? 0 : 1;
return(result);
}
/// <summary>
/// And the derivatives.
/// </summary>
/// <param name="b">The other operand.</param>
/// <returns>
/// The derivatives.
/// </returns>
public override Derivatives <Func <double> > And(Derivatives <Func <double> > b)
{
var result = new DoubleDerivatives();
var arg1 = this[0];
var arg2 = b[0];
result[0] = () => arg1().Equals(0.0) || arg2().Equals(0.0) ? 0 : 1;
return(result);
}
/// <summary>
/// Modulo operation on derivatives.
/// </summary>
/// <param name="b">The other operand.</param>
/// <returns>
/// The remainder of the division.
/// </returns>
public override Derivatives <Func <double> > Modulo(Derivatives <Func <double> > b)
{
var result = new DoubleDerivatives();
var a0 = this[0];
var b0 = b[0];
result[0] = () => a0() % b0();
return(result);
}
/// <summary>
/// Check greater than.
/// </summary>
/// <param name="b">The other operand.</param>
/// <returns>
/// A value representing true if this is greater.
/// </returns>
public override Derivatives <Func <double> > GreaterThan(Derivatives <Func <double> > b)
{
var result = new DoubleDerivatives();
var a0 = this[0];
var b0 = b[0];
result[0] = () => a0() > b0() ? 1 : 0;
return(result);
}
/// <summary>
/// Check less or equal.
/// </summary>
/// <param name="b">The other operand.</param>
/// <returns>
/// A value representing true if this is less or equal.
/// </returns>
public override Derivatives <Func <double> > LessOrEqual(Derivatives <Func <double> > b)
{
var result = new DoubleDerivatives();
var a0 = this[0];
var b0 = b[0];
result[0] = () => a0() <= b0() ? 1 : 0;
return(result);
}
/// <summary>
/// And the derivatives.
/// </summary>
/// <param name="b">The other operand.</param>
/// <returns>
/// The derivatives.
/// </returns>
public override Derivatives <Expression> And(Derivatives <Expression> b)
{
var result = new ExpressionTreeDerivatives();
result[0] = Expression.Condition(
Expression.Or(
Expression.Equal(this[0], Zero),
Expression.Equal(b[0], Zero)), Zero, One);
return(result);
}
/// <summary>
/// Divide derivatives.
/// </summary>
/// <param name="b">The other operand.</param>
/// <returns>
/// The divided result.
/// </returns>
public override Derivatives <Expression> Divide(Derivatives <Expression> b)
{
var size = Math.Max(Count, b.Count);
var result = new ExpressionTreeDerivatives(size);
Expression a0 = this[0], b0 = b[0];
if (a0 == null)
{
return(null);
}
if (b0 == null)
{
throw new DivideByZeroException();
}
result[0] = Expression.Call(Division, a0, b0);
for (var i = 1; i < size; i++)
{
if (this[i] == null)
{
if (b[i] == null)
{
result[i] = null;
}
else
{
// (a/gx)' = -a/gx^2*g'x
result[i] = Expression.Call(Division,
Expression.Negate(Expression.Multiply(a0, b[i])),
Expression.Call(SquareInfo, b0));
}
}
else
{
if (b[i] == null)
{
// (fx/b)' = f'x/b
result[i] = Expression.Call(Division, this[i], b0);
}
else
{
// (fx/gx)' = (f'x*gx-fx*g'x)/gx^2
result[i] = Expression.Call(Division,
Expression.Subtract(
Expression.Multiply(this[i], b0),
Expression.Multiply(a0, b[i])),
Expression.Call(SquareInfo, b0));
}
}
}
return(result);
}
/// <summary>
/// Check greater or equal.
/// </summary>
/// <param name="b">The operand.</param>
/// <returns>
/// A value representing true if this is greater or equal.
/// </returns>
public override Derivatives <Expression> GreaterOrEqual(Derivatives <Expression> b)
{
var result = new ExpressionTreeDerivatives();
Expression a0 = this[0], b0 = b[0];
if (a0 == null && b0 == null)
{
return(result);
}
a0 = a0 ?? Zero;
b0 = b0 ?? Zero;
result[0] = Expression.Condition(Expression.GreaterThanOrEqual(a0, b0), One, Zero); return(result);
}
/// <summary>
/// Conditional derivatives.
/// </summary>
/// <param name="iftrue">Argument if true.</param>
/// <param name="iffalse">Argument if false.</param>
/// <returns>
/// The derivatives.
/// </returns>
public override Derivatives <Func <double> > IfThenElse(Derivatives <Func <double> > iftrue, Derivatives <Func <double> > iffalse)
{
var size = Math.Max(iftrue.Count, iffalse.Count);
var result = new DoubleDerivatives(size);
var arg = this[0];
for (var i = 0; i < size; i++)
{
var arg2 = iftrue[i] ?? (() => 0.0);
var arg3 = iffalse[i] ?? (() => 0.0);
result[i] = () => arg().Equals(0.0) ? arg3() : arg2();
}
return(result);
}
/// <summary>
/// Check equality.
/// </summary>
/// <param name="obj">The other object.</param>
/// <returns></returns>
public bool Equals(Derivatives <T> obj)
{
if (obj.Count != Count)
{
return(false);
}
for (var i = 0; i < Count; i++)
{
if (!this[i].Equals(obj[i]))
{
return(false);
}
}
return(true);
}
/// <summary>
/// Modulo operation on derivatives.
/// </summary>
/// <param name="b">The other operand.</param>
/// <returns>
/// The remainder of the division.
/// </returns>
public override Derivatives <Expression> Modulo(Derivatives <Expression> b)
{
var result = new ExpressionTreeDerivatives();
if (this[0] == null)
{
return(result);
}
if (b[0] == null)
{
throw new Exception("Modulo by 0");
}
result[0] = Expression.Modulo(this[0], b[0]);
return(result);
}
/// <summary>
/// Raises the derivatives to a power.
/// </summary>
/// <param name="exponent">The exponent.</param>
/// <returns>
/// The raised power.
/// </returns>
public override Derivatives <Expression> Pow(Derivatives <Expression> exponent)
{
var size = Math.Max(Count, exponent.Count);
var result = new ExpressionTreeDerivatives(size);
Expression a0 = this[0], b0 = exponent[0];
if (a0 == null && b0 == null)
{
// This doesn't make much sense (0^0 is invalid) but Math.Pow does it like that so we will too
result[0] = One;
return(result);
}
if (a0 == null)
{
a0 = Zero;
}
if (b0 == null)
{
// (fx)^0 = 1
result[0] = One;
return(result);
}
result[0] = Expression.Call(PowInfo, a0, b0);
if (a0 != One && a0 != Zero)
{
a0 = Expression.Call(AbsInfo, a0);
}
for (var i = 1; i < size; i++)
{
// (fx^b)' = b * fx^(b-1) * f'x
if (this[i] != null)
{
result[i] = Expression.Multiply(b0, Expression.Multiply(this[i],
Expression.Call(PowInfo, a0, Expression.Subtract(b0, One))));
}
// (fx^gx)' = (e^(gx*ln(fx)))'
// = fx^(gx-1)*f'x + fx^gx*ln(fx)*g'x
if (exponent[i] != null)
{
var contribution = Expression.Multiply(Expression.Call(PowInfo, a0, b0),
Expression.Multiply(Expression.Call(LogInfo, a0), exponent[i]));
result[i] = result[i] == null ? contribution :
Expression.Add(result[i], contribution);
}
}
return(result);
}
/// <summary>
/// Raises the derivatives to a power.
/// </summary>
/// <param name="exponent">The exponent.</param>
/// <returns>The raised power.</returns>
public override Derivatives <Func <double> > Pow(Derivatives <Func <double> > exponent)
{
var size = Math.Max(Count, exponent.Count);
var result = new DoubleDerivatives(size);
var a0 = this[0];
var b0 = exponent[0];
result[0] = () => SafePow(a0(), b0());
for (var i = 1; i < size; i++)
{
if (this[i] != null && exponent[i] != null)
{
// (fx^gx)' = (e^(gx*ln(fx)))'
// = gx*fx^(gx-1)*f'x + fx^gx*ln(fx)*g'x
var ai = this[i];
var bi = exponent[i];
result[i] = () =>
{
var tmpa0 = Math.Abs(a0());
var tmpb0 = b0();
return(SafePow(tmpa0, tmpb0 - 1) * tmpb0 * ai() + SafePow(tmpa0, tmpb0) * Math.Log(tmpa0) * bi());
};
}
else if (this[i] != null)
{
// (fx^b)' = b * fx^(b-1) * f'x
var ai = this[i];
result[i] = () =>
{
var tmpa0 = Math.Abs(a0());
var tmpb0 = b0();
return(SafePow(tmpa0, tmpb0 - 1) * tmpb0 * ai());
};
}
else if (exponent[i] != null)
{
// (a^gx)' = a^gx * ln(a) * g'x
var bi = exponent[i];
result[i] = () =>
{
var tmpa0 = Math.Abs(a0());
var tmpb0 = b0();
return(SafePow(tmpa0, tmpb0) * Math.Log(tmpa0) * bi());
};
}
}
return(result);
}
/// <summary>
/// Multiply derivatives.
/// </summary>
/// <param name="b">The other operand.</param>
/// <returns>
/// The multiplied result.
/// </returns>
public override Derivatives <Expression> Multiply(Derivatives <Expression> b)
{
var size = Math.Max(Count, b.Count);
var result = new ExpressionTreeDerivatives(size);
Expression a0 = this[0], b0 = b[0];
if (a0 == null || b0 == null)
{
return(result); // x*0 = 0 and so is all its derivatives
}
else
{
result[0] = Expression.Multiply(a0, b0);
}
for (var i = 1; i < size; i++)
{
if (this[i] == null)
{
if (b[i] == null)
{
result[i] = null;
}
else
{
// (a*gx)' = a*g'x
result[i] = Expression.Multiply(a0, b[i]);
}
}
else
{
if (b[i] == null)
{
// (fx*b)' = f'x*b
result[i] = Expression.Multiply(this[i], b0);
}
else
{
// (fx*gx)' = fx*g'x + f'x*gx
result[i] = Expression.Add(
Expression.Multiply(a0, b[i]),
Expression.Multiply(this[i], b0));
}
}
}
return(result);
}
/// <summary>
/// Conditional derivatives.
/// </summary>
/// <param name="iftrue">Argument if true.</param>
/// <param name="iffalse">Argument if false.</param>
/// <returns>
/// The derivatives.
/// </returns>
public override Derivatives <Expression> IfThenElse(Derivatives <Expression> iftrue, Derivatives <Expression> iffalse)
{
if (this[0] == null)
{
return(iffalse);
}
var size = Math.Max(iftrue.Count, iffalse.Count);
var result = new ExpressionTreeDerivatives(size);
var notcondition = Expression.Equal(this[0], Zero);
for (var i = 0; i < size; i++)
{
var iftruei = iftrue[i];
var iffalsei = iffalse[i];
if (iftruei == null && iffalsei == null)
{
continue;
}
result[i] = Expression.Condition(notcondition, iffalsei ?? Zero, iftruei ?? Zero);
}
return(result);
}
/// <summary>
/// Divide derivatives.
/// </summary>
/// <param name="b">The other operand.</param>
/// <returns>
/// The divided result.
/// </returns>
public override Derivatives <Func <double> > Divide(Derivatives <Func <double> > b)
{
var size = Math.Max(Count, b.Count);
var result = new DoubleDerivatives(size);
var a0 = this[0];
var b0 = b[0];
result[0] = () => SafeDivide(a0(), b0());
for (var i = 1; i < size; i++)
{
var ai = this[i];
var bi = b[i];
if (ai != null && bi != null)
{
result[i] = () =>
{
var denom = b0();
return(SafeDivide(denom * ai() - a0() * bi(), denom * denom));
}
}
;
else if (ai != null)
{
result[i] = () => SafeDivide(ai(), b0());
}
else if (bi != null)
{
result[i] = () =>
{
var denom = b0();
return(-SafeDivide(a0() * bi(), denom * denom));
}
}
;
}
return(result);
}
/// <summary>
/// Subtract derivatives.
/// </summary>
/// <param name="b">The other operand.</param>
/// <returns>
/// The difference.
/// </returns>
public override Derivatives <Func <double> > Subtract(Derivatives <Func <double> > b)
{
var size = Math.Max(Count, b.Count);
var result = new DoubleDerivatives(size);
for (var i = 0; i < size; i++)
{
var arg1 = this[i];
var arg2 = b[i];
if (arg1 != null && arg2 != null)
{
result[i] = () => arg1() - arg2();
}
else if (arg1 != null)
{
result[i] = arg1;
}
else if (arg2 != null)
{
result[i] = () => - arg2();
}
}
return(result);
}
/// <summary>
/// Add derivatives.
/// </summary>
/// <param name="b">The other operand.</param>
/// <returns>
/// The sum.
/// </returns>
public override Derivatives <Func <double> > Add(Derivatives <Func <double> > b)
{
var size = Math.Max(Count, b.Count);
var result = new DoubleDerivatives(size);
for (var i = 0; i < size; i++)
{
var ai = this[i];
var bi = b[i];
if (ai != null && bi != null)
{
result[i] = () => ai() + bi();
}
else if (ai != null)
{
result[i] = ai;
}
else if (bi != null)
{
result[i] = bi;
}
}
return(result);
}
/// <summary> /// Check less than. /// </summary> /// <param name="b">The other operand.</param> /// <returns>A value representing true if this is less.</returns> public abstract Derivatives <T> LessThan(Derivatives <T> b);
/// <summary> /// Subtract derivatives. /// </summary> /// <param name="b">The other operand.</param> /// <returns>The difference.</returns> public abstract Derivatives <T> Subtract(Derivatives <T> b);
/// <summary> /// Multiply derivatives. /// </summary> /// <param name="b">The other operand.</param> /// <returns>The multiplied result.</returns> public abstract Derivatives <T> Multiply(Derivatives <T> b);
/// <summary> /// Check greater or equal. /// </summary> /// <param name="b">The operand.</param> /// <returns>A value representing true if this is greater or equal.</returns> public abstract Derivatives <T> GreaterOrEqual(Derivatives <T> b);
/// <summary> /// Divide derivatives. /// </summary> /// <param name="b">The other operand.</param> /// <returns>The divided result.</returns> public abstract Derivatives <T> Divide(Derivatives <T> b);
/// <summary> /// Modulo operation on derivatives. /// </summary> /// <param name="b">The other operand.</param> /// <returns>The remainder of the division.</returns> public abstract Derivatives <T> Modulo(Derivatives <T> b);
/// <summary> /// Check less or equal. /// </summary> /// <param name="b">The other operand.</param> /// <returns>A value representing true if this is less or equal.</returns> public abstract Derivatives <T> LessOrEqual(Derivatives <T> b);
/// <summary> /// Check greater than. /// </summary> /// <param name="b">The other operand.</param> /// <returns>A value representing true if this is greater.</returns> public abstract Derivatives <T> GreaterThan(Derivatives <T> b);
/// <summary>
/// Execute an operator.
/// </summary>
/// <param name="op">The operator.</param>
protected override void ExecuteOperator(Operator op)
{
Derivatives <Expression> a, b;
switch (op)
{
case TernaryOperator to:
b = _stack.Pop();
a = _stack.Pop();
_stack.Push(_stack.Pop().IfThenElse(a, b));
break;
case ClosingTernaryOperator _:
break;
case FunctionOperator fo:
// Extract all arguments for the method
var arguments = new Derivatives <Expression> [fo.Arguments];
for (var i = fo.Arguments - 1; i >= 0; i--)
{
arguments[i] = _stack.Pop();
}
var args = new FunctionFoundEventArgs <Derivatives <Expression> >(fo.Name, null, arguments);
// Ask around for the result of this method
FunctionFound?.Invoke(this, args);
if (!args.Found || args.Result == null)
{
throw new ParserException("Unrecognized method '{0}()'".FormatString(fo.Name), Input, Index);
}
_stack.Push(args.Result);
break;
case BracketOperator _:
break;
case ArgumentOperator _:
break;
case ArithmeticOperator ao:
switch (ao.Type)
{
case OperatorType.Positive:
break;
case OperatorType.Negative:
_stack.Push(_stack.Pop().Negate());
break;
case OperatorType.Not:
_stack.Push(_stack.Pop().Not());
break;
case OperatorType.Add:
b = _stack.Pop();
_stack.Push(_stack.Pop().Add(b));
break;
case OperatorType.Subtract:
b = _stack.Pop();
_stack.Push(_stack.Pop().Subtract(b));
break;
case OperatorType.Multiply:
b = _stack.Pop();
_stack.Push(_stack.Pop().Multiply(b));
break;
case OperatorType.Divide:
b = _stack.Pop();
_stack.Push(_stack.Pop().Divide(b));
break;
case OperatorType.Power:
b = _stack.Pop();
_stack.Push(_stack.Pop().Pow(b));
break;
case OperatorType.ConditionalOr:
b = _stack.Pop();
_stack.Push(_stack.Pop().Or(b));
break;
case OperatorType.ConditionalAnd:
b = _stack.Pop();
_stack.Push(_stack.Pop().And(b));
break;
case OperatorType.GreaterThan:
b = _stack.Pop();
_stack.Push(_stack.Pop().GreaterThan(b));
break;
case OperatorType.LessThan:
b = _stack.Pop();
_stack.Push(_stack.Pop().LessThan(b));
break;
case OperatorType.GreaterThanOrEqual:
b = _stack.Pop();
_stack.Push(_stack.Pop().GreaterOrEqual(b));
break;
case OperatorType.LessThanOrEqual:
b = _stack.Pop();
_stack.Push(_stack.Pop().LessOrEqual(b));
break;
case OperatorType.IsEqual:
b = _stack.Pop();
_stack.Push(_stack.Pop().Equal(b));
break;
case OperatorType.IsNotEqual:
b = _stack.Pop();
_stack.Push(_stack.Pop().NotEqual(b));
break;
default:
throw new ParserException("Unimplemented arithmetic operator", Input, Index);
}
break;
default:
throw new ParserException("Unimplemented operator", Input, Index);
}
}
