// *** ISimilarity<SparseVector<double>.ReadOnly> interface implementation ***
public double GetSimilarity(SparseVector <double> .ReadOnly a, SparseVector <double> .ReadOnly b)
{
Utils.ThrowException(a == null ? new ArgumentNullException("a") : null);
Utils.ThrowException(b == null ? new ArgumentNullException("b") : null);
double dotProd = 0;
int i = 0, j = 0;
int aCount = a.Count;
Utils.ThrowException(aCount == 0 ? new ArgumentValueException("a") : null);
int bCount = b.Count;
Utils.ThrowException(bCount == 0 ? new ArgumentValueException("b") : null);
ArrayList <int> aIdx = a.Inner.InnerIdx;
ArrayList <double> aDat = a.Inner.InnerDat;
ArrayList <int> bIdx = b.Inner.InnerIdx;
ArrayList <double> bDat = b.Inner.InnerDat;
int aIdx_i = aCount == 0 ? 0 : aIdx[0];
int bIdx_j = bCount == 0 ? 0 : bIdx[0];
while (true)
{
if (aIdx_i < bIdx_j)
{
if (++i == aCount)
{
break;
}
aIdx_i = aIdx[i];
}
else if (aIdx_i > bIdx_j)
{
if (++j == bCount)
{
break;
}
bIdx_j = bIdx[j];
}
else
{
dotProd += aDat[i] * bDat[j];
if (++i == aCount || ++j == bCount)
{
break;
}
aIdx_i = aIdx[i];
bIdx_j = bIdx[j];
}
}
double aLen = ModelUtils.GetVecLenL2(a);
Utils.ThrowException(aLen == 0 ? new ArgumentValueException("a") : null);
double bLen = ModelUtils.GetVecLenL2(b);
Utils.ThrowException(bLen == 0 ? new ArgumentValueException("b") : null);
double lenMult = aLen * bLen;
return(dotProd / lenMult);
}
// *** ISimilarity<SparseVector<double>.ReadOnly> interface implementation ***
public double GetSimilarity(SparseVector <double> .ReadOnly a, SparseVector <double> .ReadOnly b)
{
Utils.ThrowException(a == null ? new ArgumentNullException("a") : null);
Utils.ThrowException(b == null ? new ArgumentNullException("b") : null);
double dot_prod = 0;
int i = 0, j = 0;
int a_count = a.Count;
Utils.ThrowException(a_count == 0 ? new ArgumentValueException("a") : null);
int b_count = b.Count;
Utils.ThrowException(b_count == 0 ? new ArgumentValueException("b") : null);
ArrayList <int> a_idx = a.Inner.InnerIdx;
ArrayList <double> a_dat = a.Inner.InnerDat;
ArrayList <int> b_idx = b.Inner.InnerIdx;
ArrayList <double> b_dat = b.Inner.InnerDat;
int a_idx_i = a_count == 0 ? 0 : a_idx[0];
int b_idx_j = b_count == 0 ? 0 : b_idx[0];
while (true)
{
if (a_idx_i < b_idx_j)
{
if (++i == a_count)
{
break;
}
a_idx_i = a_idx[i];
}
else if (a_idx_i > b_idx_j)
{
if (++j == b_count)
{
break;
}
b_idx_j = b_idx[j];
}
else
{
dot_prod += a_dat[i] * b_dat[j];
if (++i == a_count || ++j == b_count)
{
break;
}
a_idx_i = a_idx[i];
b_idx_j = b_idx[j];
}
}
double len_a = ModelUtils.GetVecLenL2(a);
Utils.ThrowException(len_a == 0 ? new ArgumentValueException("a") : null);
double len_b = ModelUtils.GetVecLenL2(b);
Utils.ThrowException(len_b == 0 ? new ArgumentValueException("b") : null);
double len_mult = len_a * len_b;
return(dot_prod / len_mult);
}