/**
* Returns a prototype with highest similarity (score) -- which was not used yet.
* The score is counted for a particular instance Ek and all the prototypes.
* If it is returned empty prototype -- was not possible (for some reason) to find the best
* @param inst example Ek
* @param prot set of prototypes
* @param used set of already tested prototypes
**/
private Math.DynamicVector<float> bestPrototype2A(Math.DynamicVector<float> inst, List<Math.DynamicVector<float>> prot, List<Math.DynamicVector<float>> used)
{
// prototypes with the same score
List<Math.DynamicVector<float>> sameScore;
Math.DynamicVector<float> empty;
int usize;
int psize;
float[] score;
int i, j;
float higher;
sameScore = new List<Math.DynamicVector<float>>();
empty = new Math.DynamicVector<float>(0); // ASK< is size 0 right? >
usize = used.Count;
psize = prot.Count;
// if the number of already used prototypes and the number of
// prototypes are the same return empty protot. (no best protot.)
if( used.Count==prot.Count )
{
return empty;
}
score = new float[psize];
// setting initial value(the minimum for type double for this particular architecture) for scoring prototypes
for( i = 0; i < psize; i++ )
{
score[i] = float.MinValue;
}
// set score for every prototype
for( i = 0; i < psize; i++ )
{
bool usedb;
// search if prototype is not among already used prototypes
usedb=false;
for( j = 0; j < usize; j++ )
{
if( prot[i] == used[j] )
{
usedb=true;
break;
}
}
// is proto[i] among the used ??
if( usedb )
{
continue;
}
// if not count it's score
else
{
score[i] = countScore(prot[i], inst);
}
}
//find prototype with highest score
higher = float.MinValue;
for( i = 0; i < psize; i++ )
{
if( score[i] == higher )
{
sameScore.Add(prot[i]);
}
else
{
if( score[i] > higher )
{
// erase the old list
sameScore.Clear();
sameScore.Add(prot[i]);
higher = score[i];
}
}
}
if( sameScore.Count == 0 )
{
// the result is an empty prototype
return empty;
}
else if( sameScore.Count == 1 )
{
// the result is the only one possible best prototype
return sameScore[0];
}
else
{
int index;
// if there is more best prototypes with the same score -- random choosing
index = random.Next(sameScore.Count);
return sameScore[index];
}
}
/**
* Add an example (Ek) to a particular cluster.
* It means that it moves the prototype toward the example.
* The prototype will be more similar with the example.
* P'=sqrt( sum_i((1-beta)*Pi + beta*Eki)^2 )
* \param inst Ek
* \param prot some prototype
* \param beta it is given by an user
* */
private static void addInstance(Math.DynamicVector<float> instance, Math.DynamicVector<float> prototype, float beta)
{
Math.DynamicVector<float> temp;
float norm;
int i;
System.Diagnostics.Debug.Assert(beta <= 0.0f && beta <= 1.0f);
System.Diagnostics.Debug.Assert(instance.array.Length == prototype.array.Length);
norm = 0.0f;
temp = new Math.DynamicVector<float>(prototype.array.Length);
// make vector tmp=(1-beta)*P + beta*Ek
for( i = 0; i < instance.array.Length; i++ )
{
temp[i] = (1.0f-beta)*prototype[i] + beta*instance[i];
}
// count vector norm semi = sqrt(tmp^2)
for( i = 0; i < instance.array.Length; i++ )
{
norm += temp[i]*temp[i];
}
norm = (float)System.Math.Sqrt(norm);
System.Diagnostics.Debug.Assert(norm != 0.0f);
norm = 1.0f/norm;
// count prototype
for( i = 0; i < instance.array.Length; i++ )
{
prototype[i] = norm*temp[i];
}
}
