private static void VectorApply(float[] ret, float[] categoriesByOrigin, float[] friction, float[] dStar, float[] columnTotals, int categories)
{
var numberOfZones = columnTotals.Length;
// For now parallel has been taken out to ensure that there is no rounding error level difference between runs. If this becomes a problem we can rebuild it with a parallel algorithm
// that guarantees constancy between runs.
// Currently the efficiency of using Multiply2Scalar1AndColumnSum beats doing parallel with 8 cores and just multiplying and then going back to calculate the column sums
for (int i = 0; i < numberOfZones; i++)
{
for (int k = 0; k < categories; k++)
{
var catByOrigin = categoriesByOrigin[i + k * numberOfZones];
if (catByOrigin <= 0)
{
continue;
}
int index = (k * numberOfZones * numberOfZones) + (i * numberOfZones);
var sumAf = VectorHelper.MultiplyAndSum(friction, index, dStar, 0, numberOfZones);
if (sumAf <= 0)
{
continue;
}
VectorHelper.Multiply2Scalar1AndColumnSum(ret, index, friction, index, dStar, 0, catByOrigin / sumAf, columnTotals, 0, numberOfZones);
}
}
}
private static void VectorApply(float[] ret, float[] categoriesByOrigin, float[] friction, float[] dStar, float[] columnTotals, int categories)
{
var numberOfZones = columnTotals.Length;
Parallel.For(0, columnTotals.Length, new ParallelOptions()
{
MaxDegreeOfParallelism = Environment.ProcessorCount
},
() => new float[columnTotals.Length],
(int i, ParallelLoopState state, float[] localTotals) =>
{
for (int k = 0; k < categories; k++)
{
var catByOrigin = categoriesByOrigin[i + k * numberOfZones];
if (catByOrigin <= 0)
{
continue;
}
int index = (k * numberOfZones * numberOfZones) + (i * numberOfZones);
var sumAF = VectorHelper.MultiplyAndSum(friction, index, dStar, 0, numberOfZones);
if (sumAF <= 0)
{
continue;
}
VectorHelper.Multiply2Scalar1AndColumnSum(ret, index, friction, index, dStar, 0, catByOrigin / sumAF, localTotals, 0, numberOfZones);
}
return(localTotals);
},
(float[] localTotals) =>
{
lock (columnTotals)
{
VectorHelper.Add(columnTotals, 0, columnTotals, 0, localTotals, 0, columnTotals.Length);
}
});
}