private void PrintData(AlgStats stats)
{
var actualDoubleFormatted = stats.ActualDoublingRatio < 0
? "na".PadLeft(20)
: stats.ActualDoublingRatio.ToString("F2").PadLeft(20);
var expectDoubleFormatted = stats.ExpectedDoublingRatio < 0
? "na".PadLeft(16)
: stats.ExpectedDoublingRatio.ToString("F2").PadLeft(16);
Console.Write(
$"{stats.TimeMicro,20:F2} {actualDoubleFormatted} {expectDoubleFormatted} {stats.AlgResult,30:N0} {Math.Ceiling(Math.Log2(stats.n)),12:N0}");
}
public void FibLoopDoublingCalc(AlgStats algStats)
{
// Only calculate doubling ratios for even values of n and if n/2 exists in prev times table.
if (algStats.n % 2 == 0 && algStats.PrevTimesTable.TryGetValue(algStats.n / 2, out double halfTime))
{
algStats.ActualDoublingRatio = (algStats.TimeMicro / halfTime);
algStats.ExpectedDoublingRatio = algStats.n / ((double)algStats.n / 2);
}
else
{
algStats.ActualDoublingRatio = -1;
algStats.ExpectedDoublingRatio = -1;
}
}
public void FibMatrixDoublingCalc(AlgStats algStats)
{
// Only calculate doubling ratios for even values of n and if n/2 exists in prev times table. n must be > 2 for log, otherwise div by 0.
if (algStats.n > 2 && algStats.n % 2 == 0 && algStats.PrevTimesTable.TryGetValue(algStats.n / 2, out double halfTime))
{
algStats.ActualDoublingRatio = (algStats.TimeMicro / halfTime);
algStats.ExpectedDoublingRatio = Math.Log2(algStats.n) / Math.Log2(((double)algStats.n / 2));
}
else
{
algStats.ActualDoublingRatio = -1;
algStats.ExpectedDoublingRatio = -1;
}
}
public void FibRecurDoublingCalc(AlgStats algStats)
{
// Only calculate doubling ratios for even values of n and if n/2 exists in prev times table.
if (algStats.n % 2 == 0 && algStats.PrevTimesTable.TryGetValue(algStats.n / 2, out double halfTime))
{
algStats.ActualDoublingRatio = (algStats.TimeMicro / halfTime);
double goldenRatio = 1.61803398875;
algStats.ExpectedDoublingRatio = Math.Pow(goldenRatio, algStats.n) / Math.Pow(goldenRatio, ((double)algStats.n / 2));
}
else
{
algStats.ActualDoublingRatio = -1;
algStats.ExpectedDoublingRatio = -1;
}
}
private void AlgorithmTestRuntime(Algorithm algorithm, DoublingCalculator doublingCalc)
{
PrintHeader(algorithm);
var currentStats = new AlgStats();
for (var n = NMin; n < NMax; n++)
{
currentStats.n = n;
if (currentStats.TimeMicro > MaxMicroSecondsPerAlg)
{
PrintAlgorithmTerminationMessage(algorithm);
break;
}
PrintIndexColumn(currentStats.n);
int testCount = 1;
int maxTest = 1000000;
long tickCounter = 0;
while (testCount <= maxTest && TicksToMicroseconds(tickCounter) < MaxMicroSecondsPerIteration)
{
_stopwatch.Restart();
currentStats.AlgResult = algorithm(n);
_stopwatch.Stop();
tickCounter += _stopwatch.ElapsedTicks;
testCount++;
}
double averageTimeMicro = TicksToMicroseconds(tickCounter) / testCount;
currentStats.PrevTimeMicro = currentStats.TimeMicro;
currentStats.TimeMicro = averageTimeMicro;
// Need to keep a dictionary of previous times for doubling calculation on this alg.
currentStats.PrevTimesTable.TryAdd(currentStats.n, averageTimeMicro);
doublingCalc(currentStats);
PrintData(currentStats);
// New Row
Console.WriteLine();
}
}