private float FindMinObjParallel(float GMax, OrderablePartitioner <Tuple <int, int> > rangePart, int i, float[] Q_i, SortedNVal minIdx)
{
float GMax2Tmp = -INF;
//todo: to many allocation, use range partitioner
Parallel.ForEach(rangePart, () => new Pair <float, Pair <int, float> >(-INF, new Pair <int, float>(-1, INF)),
(range, loopState, maxMinPair) =>
{
int endRange = range.Item2;
for (int j = range.Item1; j < endRange; j++)
{
if (y[j] == +1)
{
if (!is_lower_bound(j))
{
float grad_diff = GMax + G[j];
if (G[j] >= maxMinPair.First)
{
maxMinPair.First = G[j];
}
if (grad_diff > 0)
{
float obj_diff;
float quad_coef = (float)(Q_i[i] + QD[j] - 2.0 * y[i] * Q_i[j]);
if (quad_coef > 0)
{
obj_diff = -(grad_diff * grad_diff) / quad_coef;
}
else
{
obj_diff = (float)(-(grad_diff * grad_diff) / 1e-12);
}
if (obj_diff < maxMinPair.Second.Second)
{
maxMinPair.Second.First = j;
maxMinPair.Second.Second = obj_diff;
}
}
}
}
else
{
if (!is_upper_bound(j))
{
float grad_diff = GMax - G[j];
if (-G[j] >= maxMinPair.First)
{
maxMinPair.First = -G[j];
}
if (grad_diff > 0)
{
float obj_diff;
float quad_coef = (float)(Q_i[i] + QD[j] + 2.0 * y[i] * Q_i[j]);
if (quad_coef > 0)
{
obj_diff = -(grad_diff * grad_diff) / quad_coef;
}
else
{
obj_diff = (float)(-(grad_diff * grad_diff) / 1e-12);
}
if (obj_diff < maxMinPair.Second.Second)
{
maxMinPair.Second.First = j;
maxMinPair.Second.Second = obj_diff;
}
}
}
}
}
return(maxMinPair);
},
(maxMinPair) =>
{
lock (lockObj)
{
if (GMax2Tmp < maxMinPair.First)
{
GMax2Tmp = maxMinPair.First;
}
//todo: in this solver we use only one value and index,
minIdx.Add(maxMinPair.Second.First, maxMinPair.Second.Second);
}
}
);
return(GMax2Tmp);
}
//todo: remove it later, not efective
private float FindMinObjParallel2(float GMax, int i, float[] Q_i, SortedNVal minIdx)
{
// object lockObj = new object();
float GMax2Tmp = -INF;
//
Parallel.For(0, active_size, () => new Pair <float, Pair <int, float> >(-INF, new Pair <int, float>(-1, INF)),
(j, loopState, maxMinPair) =>
{
if (y[j] == +1)
{
if (!is_lower_bound(j))
{
float grad_diff = GMax + G[j];
if (G[j] >= maxMinPair.First)
{
maxMinPair.First = G[j];
}
if (grad_diff > 0)
{
float obj_diff;
float quad_coef = (float)(Q_i[i] + QD[j] - 2.0 * y[i] * Q_i[j]);
if (quad_coef > 0)
{
obj_diff = -(grad_diff * grad_diff) / quad_coef;
}
else
{
obj_diff = (float)(-(grad_diff * grad_diff) / 1e-12);
}
if (obj_diff < maxMinPair.Second.Second)
{
maxMinPair.Second.First = j;
maxMinPair.Second.Second = obj_diff;
}
}
}
}
else
{
if (!is_upper_bound(j))
{
float grad_diff = GMax - G[j];
if (-G[j] >= maxMinPair.First)
{
maxMinPair.First = -G[j];
}
if (grad_diff > 0)
{
float obj_diff;
float quad_coef = (float)(Q_i[i] + QD[j] + 2.0 * y[i] * Q_i[j]);
if (quad_coef > 0)
{
obj_diff = -(grad_diff * grad_diff) / quad_coef;
}
else
{
obj_diff = (float)(-(grad_diff * grad_diff) / 1e-12);
}
if (obj_diff < maxMinPair.Second.Second)
{
maxMinPair.Second.First = j;
maxMinPair.Second.Second = obj_diff;
}
}
}
}
//if (maxMinPair.Second.First == -1)
// return null;
return(maxMinPair);
},
(maxMinPair) =>
{
if (maxMinPair != null && maxMinPair.Second.First != -1)
{
lock (lockObj)
{
if (GMax2Tmp < maxMinPair.First)
{
GMax2Tmp = maxMinPair.First;
}
minIdx.Add(maxMinPair.Second.First, maxMinPair.Second.Second);
}
}
}
);
return(GMax2Tmp);
}
private float FindMinObjSeq(float GMax, float GMax2, int i, float[] Q_i, SortedNVal minIdx)
{
for (int j = 0; j < active_size; j++)
{
if (y[j] == +1)
{
if (!is_lower_bound(j))
{
float grad_diff = GMax + G[j];
if (G[j] >= GMax2)
{
GMax2 = G[j];
}
if (grad_diff > 0)
{
float obj_diff;
float quad_coef = (float)(Q_i[i] + QD[j] - 2.0 * y[i] * Q_i[j]);
if (quad_coef > 0)
{
obj_diff = -(grad_diff * grad_diff) / quad_coef;
}
else
{
obj_diff = (float)(-(grad_diff * grad_diff) / 1e-12);
}
minIdx.Add(j, obj_diff);
//if (obj_diff < obj_diff_Min) //previous "<="
//{
// GMin_idx = j;
// obj_diff_Min = obj_diff;
// // minSecIdx.Add(new KeyValuePair<int, float>(j, obj_diff_Min));
//}
//else if (obj_diff_Min < obj_diff_NMin)
//{
// // minSecIdx.Add(new KeyValuePair<int, float>(j, obj_diff));
//}
//else continue;
}
//else continue;
}
//else continue;
}
else
{
if (!is_upper_bound(j))
{
float grad_diff = GMax - G[j];
if (-G[j] >= GMax2)
{
GMax2 = -G[j];
}
if (grad_diff > 0)
{
float obj_diff;
float quad_coef = (float)(Q_i[i] + QD[j] + 2.0 * y[i] * Q_i[j]);
if (quad_coef > 0)
{
obj_diff = -(grad_diff * grad_diff) / quad_coef;
}
else
{
obj_diff = (float)(-(grad_diff * grad_diff) / 1e-12);
}
minIdx.Add(j, obj_diff);
//if (obj_diff < obj_diff_Min)
//{
// GMin_idx = j;
// obj_diff_Min = obj_diff;
// //minSecIdx.Add(new KeyValuePair<int, float>(j, obj_diff_Min));
//}
//else if (obj_diff < obj_diff_NMin)
//{
// minSecIdx.Add(new KeyValuePair<int, float>(j, obj_diff));
//}
//else continue;
}
//else continue;
}
//else continue;
}
//if (minSecIdx.Count > pairsCount)
//{
// var minPair = minSecIdx.Min;
// minSecIdx.Remove(minPair);
// obj_diff_NMin = minPair.Value;
//}
}
return(GMax2);
}
