/// <summary>
/// ermittelt alle einzel und doppel Kombinationen aller Widerstände und gibt diese sortiert zurück
/// </summary>
/// <param name="allResistors">Liste mit allen Basis-Widerständen</param>
/// <returns>fertig sortierte Liste mit entsprechenden Widerständen</returns>
static KeyValuePair <long, Resistor>[] GetAllDoubles(Resistor[] allResistors)
{
if (doubleCache != null)
{
return(doubleCache);
}
var result = new KeyValuePair <long, Resistor> [allResistors.Length * allResistors.Length];
int p = 0;
foreach (var r in allResistors)
{
result[p++] = new KeyValuePair <long, Resistor>(r.valueMilliOhm, r);
}
// --- serielle und parallele Kombinationen sammeln ---
for (int y = 0; y < allResistors.Length - 1; y++)
{
for (int x = y + 1; x < allResistors.Length; x++)
{
var rs = new ResistorCombined(true, allResistors[x], allResistors[y]);
var rp = new ResistorCombined(false, allResistors[x], allResistors[y]);
result[p++] = new KeyValuePair <long, Resistor>(rs.valueMilliOhm, rs);
result[p++] = new KeyValuePair <long, Resistor>(rp.valueMilliOhm, rp);
}
}
Array.Sort(result, (x, y) => x.Key.CompareTo(y.Key));
return(doubleCache = result);
}
/// <summary>
/// Suchmethode, um passende Widerstände bzw. deren Kombinationen zu finden
/// </summary>
/// <param name="allResistors">Alle Widerstände, welche zur Verfügung stehen</param>
/// <param name="searchValue">gesuchter Widerstandswert</param>
/// <param name="maxResistors">optional: gibt die maximale Anzahl der kombinierbaren Widerstände an, welche verwendet werden dürfen (default: 2)</param>
/// <param name="maxError">optional: maximale Abweichung des Ergebnisses (default: 1.10 = 10 % Abweichung)</param>
/// <returns>Enumerable der gefundenen Ergebnisse</returns>
public static IEnumerable <ResistorResult> Search(Resistor[] allResistors, Resistor searchValue, int maxResistors = 2, double maxError = 1.10)
{
if (allResistors.Length < 2)
{
yield break;
}
long search = searchValue.valueMilliOhm;
long max = (long)(search * maxError) - search;
foreach (var r in allResistors)
{
long err = Math.Abs(r.valueMilliOhm - search);
if (err <= max)
{
yield return(new ResistorResult(r, err));
}
}
var fullList = GetAllDoubles(allResistors);
var fullRevList = GetAllRevDoubles(allResistors);
if (maxResistors >= 2) // 2-teilige Suche
{
int p = BinarySearch(fullList, search - max);
while (p < fullList.Length && fullList[p].Key - search < max)
{
yield return(new ResistorResult(fullList[p].Value, Math.Abs(search - fullList[p].Key)));
p++;
}
}
if (maxResistors >= 3)
{
// --- 3er Kombination - seriell ---
for (int z = 0; z < allResistors.Length - 2; z++)
{
for (int y = z + 1; y < allResistors.Length - 1; y++)
{
for (int x = y + 1; x < allResistors.Length; x++)
{
long err = Math.Abs(allResistors[x].valueMilliOhm + allResistors[y].valueMilliOhm + allResistors[z].valueMilliOhm - search);
if (err <= max)
{
yield return(new ResistorResult(new ResistorCombined(true, allResistors[x], allResistors[y], allResistors[z]), err));
}
}
}
}
// --- 3er Kombination - parallel ---
for (int z = 0; z < allResistors.Length - 2; z++)
{
for (int y = z + 1; y < allResistors.Length - 1; y++)
{
for (int x = y + 1; x < allResistors.Length; x++)
{
var c = new ResistorCombined(false, allResistors[x], allResistors[y], allResistors[z]);
long err = Math.Abs(c.valueMilliOhm - search);
if (err <= max)
{
yield return(new ResistorResult(c, err));
}
}
}
}
}
}
