private void ProduceTask(double up, double down,
int concurr_num, MinMaxVal result, Function.Function function)
{
if (concurr_num >= (int)((up - down) / precision))
{
for (double x = down + precision; x < up; x += precision)
{
double temp = x;
Task <MinMaxVal> task = Task.Run(() => ThreadCalSingle(temp));
taskList.Add(task);
}
result.MinVal = Math.Min(result.MinVal, function.GetValue(up));
result.MaxVal = Math.Max(result.MaxVal, function.GetValue(up));
}
else
{
interval = (up - down) / (2 * concurr_num);
double x = down + interval;
for (; x < up; x += interval)
{
double temp = x;
Task <MinMaxVal> task = Task.Run(() => ThreadCalMutiple(temp));
taskList.Add(task);
}
for (x = (x - interval + precision); x < up; x += precision)
{
result.MinVal = Math.Min(result.MinVal, function.GetValue(x));
result.MaxVal = Math.Max(result.MaxVal, function.GetValue(x));
}
result.MinVal = Math.Min(result.MinVal, function.GetValue(up));
result.MaxVal = Math.Max(result.MaxVal, function.GetValue(up));
}
}
public void ExtremumCal(double up, double down, string exp,
out double min, out double max,
int concurr_num = 50000)
{
if (up < down)
{
throw new Exception("上界不可小于下界！");
}
taskList.Clear();
MinMaxVal result = new MinMaxVal();
funcExp = exp;
Function.Function function = new Function.Function(exp);
result.MaxVal = function.GetValue(down);
result.MinVal = function.GetValue(down);
ProduceTask(up, down, concurr_num, result, function);
Task.WaitAll(taskList.ToArray());
foreach (Task <MinMaxVal> t in taskList)
{
result.MinVal = Math.Min(result.MinVal, t.Result.MinVal);
result.MaxVal = Math.Max(result.MaxVal, t.Result.MaxVal);
}
min = result.MinVal;
max = result.MaxVal;
}
private MinMaxVal ThreadCalSingle(double x)
{
Function.Function function = new Function.Function(funcExp);
MinMaxVal temp = new MinMaxVal();
temp.MaxVal = function.GetValue(x);
temp.MinVal = temp.MaxVal;
return(temp);
}
private MinMaxVal ThreadCalMutiple(double x)
{
Function.Function function = new Function.Function(funcExp);
MinMaxVal temp = new MinMaxVal();
temp.MaxVal = function.GetValue(x);
temp.MinVal = temp.MaxVal;
for (double t = precision; t < interval; t += precision)
{
double result = function.GetValue(x);
temp.MaxVal = Math.Max(temp.MaxVal, result);
temp.MinVal = Math.Min(temp.MinVal, result);
}
return(temp);
}
