// Generates the average (and variance) of the list of sound features, ASSUMING
// that all sound features use the same time values
public static SoundFeature GenerateAverage(List <SoundFeature> soundFeatureList)
{
SoundFeature averageSoundFeature = new SoundFeature();
if (soundFeatureList.Count > 0)
{
averageSoundFeature.Name = soundFeatureList[0].Name;
int size = soundFeatureList[0].TimeList.Count;
averageSoundFeature.SetSize(size);
for (int jj = 0; jj < size; jj++)
{
averageSoundFeature.TimeList[jj] = soundFeatureList[0].TimeList[jj];
}
for (int jj = 0; jj < size; jj++)
{
List <double> featureValueList = new List <double>();
for (int ii = 0; ii < soundFeatureList.Count; ii++)
{
featureValueList.Add(soundFeatureList[ii].ValueList[jj]);
}
double average = featureValueList.Average();
double variance = Variance.Compute(featureValueList);
averageSoundFeature.ValueList[jj] = average;
averageSoundFeature.VarianceList[jj] = variance;
}
}
return(averageSoundFeature);
}
// Generates the average sound feature set from a list of sound feature sets (one for
// each instance of a sound). It is assumed that all sound feature sets contain the
// same features, in the same order.
public static SoundFeatureSet GenerateAverage(List <SoundFeatureSet> soundFeatureSetList)
{
SoundFeatureSet averageSoundFeatureSet = new SoundFeatureSet();
int numberOfFeatures = soundFeatureSetList[0].FeatureList.Count;
for (int iFeature = 0; iFeature < numberOfFeatures; iFeature++)
{
List <SoundFeature> soundFeatureList = new List <SoundFeature>();
for (int iInstance = 0; iInstance < soundFeatureSetList.Count; iInstance++)
{
soundFeatureList.Add(soundFeatureSetList[iInstance].FeatureList[iFeature]);
}
SoundFeature averageFeature = SoundFeature.GenerateAverage(soundFeatureList);
averageFeature.NumberOfInstances = soundFeatureSetList.Count; // Number of instances used when forming the average.
averageSoundFeatureSet.FeatureList.Add(averageFeature);
}
return(averageSoundFeatureSet);
}
public static double GetDeviation(SoundFeatureSet soundFeatureSet1, SoundFeatureSet soundFeatureSet2, List <double> weightList)
{
if (soundFeatureSet1.FeatureList.Count != soundFeatureSet2.FeatureList.Count)
{
return(double.MaxValue);
}
else
{
double deviation = 0;
int numberOfNonZeroWeights = 0;
for (int iFeature = 0; iFeature < soundFeatureSet1.FeatureList.Count; iFeature++)
{
double weight = weightList[iFeature];
if (weight > double.Epsilon)
{
numberOfNonZeroWeights++;
double featureDeviation = 0;
SoundFeature feature1 = soundFeatureSet1.FeatureList[iFeature];
SoundFeature feature2 = soundFeatureSet2.FeatureList[iFeature];
if (feature1.TimeList.Count != feature2.TimeList.Count)
{
return(double.MaxValue);
}
else
{
for (int jj = 0; jj < feature1.TimeList.Count; jj++)
{
featureDeviation += (feature1.ValueList[jj] - feature2.ValueList[jj]) *
(feature1.ValueList[jj] - feature2.ValueList[jj]);
}
}
deviation += weight * Math.Sqrt(featureDeviation / (double)feature1.ValueList.Count);
}
}
deviation /= (double)soundFeatureSet1.FeatureList.Count;
deviation /= (double)numberOfNonZeroWeights;
return(deviation);
}
}
