/// <summary>Gets the value of the integral \int_a^b f(x) dx.
/// </summary>
/// <param name="lowerBound">The lower bound.</param>
/// <param name="upperBound">The upper bound.</param>
/// <returns>The value of \int_a^b f(x) dx.</returns>
/// <remarks>The arguments must be elements of the domain of definition, represented by <see cref="IRealValuedCurve.LowerBound"/> and <see cref="IRealValuedCurve.UpperBound"/>.</remarks>
public double GetIntegral(double lowerBound, double upperBound)
{
int sign = 1;
if (upperBound > lowerBound)
{
sign = -1;
var temp = upperBound;
upperBound = lowerBound;
lowerBound = temp;
}
var curveBuilderLowerBound = m_CurveBuilder.LowerBound;
var curveBuilderUpperBound = m_CurveBuilder.UpperBound;
/* we split the integral in parts which are outside and which are inside the range: */
if (lowerBound < curveBuilderLowerBound)
{
if (upperBound < curveBuilderLowerBound)
{
return(sign * m_LeftExtrapolator.GetIntegral(lowerBound, upperBound));
}
double integralValue = m_LeftExtrapolator.GetIntegral(lowerBound, curveBuilderLowerBound);
if (upperBound < curveBuilderUpperBound)
{
return(sign * (integralValue + m_CurveBuilder.GetIntegral(curveBuilderLowerBound, upperBound)));
}
return(sign * (integralValue + m_CurveBuilder.GetIntegral(curveBuilderLowerBound, curveBuilderUpperBound) + m_RightExtrapolator.GetIntegral(curveBuilderUpperBound, upperBound)));
}
else if (lowerBound > curveBuilderUpperBound)
{
return(sign * m_RightExtrapolator.GetIntegral(lowerBound, upperBound)); /* here we assume lowerBound < upperBound */
}
if (upperBound <= curveBuilderUpperBound)
{
return(sign * m_CurveBuilder.GetIntegral(lowerBound, upperBound));
}
return(sign * (m_CurveBuilder.GetIntegral(lowerBound, curveBuilderUpperBound) + m_RightExtrapolator.GetIntegral(curveBuilderUpperBound, upperBound)));
}
/// <summary>Gets the value of the integral \int_a^b f(x) dx.
/// </summary>
/// <param name="lowerBound">The lower bound.</param>
/// <param name="upperBound">The upper bound.</param>
/// <returns>The value of \int_a^b f(x) dx.</returns>
/// <remarks>The arguments must be elements of the domain of definition, represented by <see cref="IRealValuedCurve.LowerBound"/> and <see cref="IRealValuedCurve.UpperBound"/>.</remarks>
public double GetIntegral(double lowerBound, double upperBound)
{
int sign = 1;
if (upperBound > lowerBound)
{
sign = -1;
var temp = upperBound;
upperBound = lowerBound;
lowerBound = temp;
}
var timeAtZero = m_CurveInterpolator.LowerBound;
var timeAtLastPoint = m_CurveInterpolator.UpperBound;
/* we split the integral in parts which are outside and which are inside the range: */
if (lowerBound < timeAtZero)
{
if (upperBound < timeAtZero)
{
return(sign * m_LeftExtrapolator.GetIntegral(lowerBound, upperBound));
}
double integralValue = m_LeftExtrapolator.GetIntegral(lowerBound, timeAtZero);
if (upperBound < timeAtLastPoint)
{
return(sign * (integralValue + m_CurveInterpolator.GetIntegral(timeAtZero, upperBound)));
}
return(sign * (integralValue + m_CurveInterpolator.GetIntegral(timeAtZero, timeAtLastPoint) + m_RightExtrapolator.GetIntegral(timeAtLastPoint, upperBound)));
}
else if (lowerBound > timeAtLastPoint)
{
return(sign * m_RightExtrapolator.GetIntegral(lowerBound, upperBound)); /* here we assume lowerBound < upperBound */
}
if (upperBound <= timeAtLastPoint)
{
return(sign * m_CurveInterpolator.GetIntegral(lowerBound, upperBound));
}
return(sign * (m_CurveInterpolator.GetIntegral(lowerBound, timeAtLastPoint) + m_RightExtrapolator.GetIntegral(timeAtLastPoint, upperBound)));
}
