/// <summary>
/// Set the parameters to match the moments of a mixture distribution.
/// </summary>
/// <param name="dist1">The first distribution</param>
/// <param name="weight1">The first weight</param>
/// <param name="dist2">The second distribution</param>
/// <param name="weight2">The second weight</param>
public void SetToSum(double weight1, TruncatedGamma dist1, double weight2, TruncatedGamma dist2)
{
if (weight1 + weight2 == 0)
{
SetToUniform();
}
else if (weight1 + weight2 < 0)
{
throw new ArgumentException("weight1 (" + weight1 + ") + weight2 (" + weight2 + ") < 0");
}
else if (weight1 == 0)
{
SetTo(dist2);
}
else if (weight2 == 0)
{
SetTo(dist1);
}
// if dist1 == dist2 then we must return dist1, with no roundoff error
else if (dist1.Equals(dist2))
{
SetTo(dist1);
}
else if (double.IsPositiveInfinity(weight1))
{
if (double.IsPositiveInfinity(weight2))
{
throw new ArgumentException("both weights are infinity");
}
else
{
SetTo(dist1);
}
}
else if (double.IsPositiveInfinity(weight2))
{
SetTo(dist2);
}
else if (dist1.LowerBound == dist2.LowerBound && dist1.UpperBound == dist2.UpperBound)
{
Gamma.SetToSum(weight1, dist1.Gamma, weight2, dist2.Gamma);
}
else
{
throw new NotImplementedException();
}
}
