public double CosineSimilarity(SparseIntegerVector other)
{
double den = this.Norm() * other.Norm();
double agg = 0;
int i = 0;
int j = 0;
while (i < Keys.Length && j < other.Keys.Length)
{
int k1 = Keys[i];
int k2 = other.Keys[j];
if (k1 == k2)
{
agg += 1.0 * Values[i] * other.Values[j] / den;
i++;
j++;
}
else if (k1 < k2)
{
i++;
}
else
{
j++;
}
}
return(agg);
}
public int Intersection(SparseIntegerVector other)
{
int agg = 0;
int i = 0;
int j = 0;
while (i < Keys.Length && j < other.Keys.Length)
{
int k1 = Keys[i];
int k2 = other.Keys[j];
if (k1 == k2)
{
agg++;
i++;
j++;
}
else if (k1 < k2)
{
i++;
}
else
{
j++;
}
}
return(agg);
}
public double DotProduct(SparseIntegerVector other)
{
double agg = 0;
int i = 0;
int j = 0;
while (i < Keys.Length && j < other.Keys.Length)
{
int k1 = Keys[i];
int k2 = other.Keys[j];
if (k1 == k2)
{
agg += 1.0 * Values[i] * other.Values[j];
i++;
j++;
}
else if (k1 < k2)
{
i++;
}
else
{
j++;
}
}
return(agg);
}
public double QGram(SparseIntegerVector other)
{
double agg = 0;
int i = 0, j = 0;
int k1, k2;
while (i < Keys.Length && j < other.Keys.Length)
{
k1 = Keys[i];
k2 = other.Keys[j];
if (k1 == k2)
{
agg += Math.Abs(Values[i] - other.Values[j]);
i++;
j++;
}
else if (k1 < k2)
{
agg += Math.Abs(Values[i]);
i++;
}
else
{
agg += Math.Abs(other.Values[j]);
j++;
}
}
// Maybe one of the two vectors was not completely walked...
while (i < Keys.Length)
{
agg += Math.Abs(Values[i]);
i++;
}
while (j < other.Keys.Length)
{
agg += Math.Abs(other.Values[j]);
j++;
}
return(agg);
}
public int Union(SparseIntegerVector other)
{
return(Size + other.Size - this.Intersection(other));
}
public double Jaccard(SparseIntegerVector other)
{
int intersection = this.Intersection(other);
return((double)intersection / (Size + other.Size - intersection));
}
