Question

我有一个班级泵

public class Pump
{
    public string Name { get; set; }
    public int PSI_min { get; set; }
    public int PSI_max { get; set; }
    public int Horsepower_min { get; set; }
    public Bitmap Graph { get; set; }
    public int RPM { get; set; }

    public Pump (string name, int psi_min, int psi_max, int horsepower_min)
    {
        Name = name;
        PSI_min = psi_min;
        PSI_max = psi_max;
        Horsepower_min = horsepower_min;
    }
}

我可以根据用户输入（PSI，HP和RPM）找到适合的泵

public void Calculate()
{
        for (int i=0; i<9; i++)
        {
            Pump pump = pumps[i];

            if (pump.PSI_min <= givenPSI && pump.PSI_max >= givenPSI && pump.Horsepower_min <= givenHorsepower && pump.RPM == givenRPM)
            {
                pumpsThatFit.Add(pump);
            }
        }

现在，如果没有完全匹配的泵（PSI太高，HP太低等等），我试图找到一种让程序获得最近可用泵的方法。但我无法想办法。有什么想法吗？

Answer 1

一种方法是计算泵和用户定义的泵之间的euclidian distance，然后选择最接近的泵。

计算两个向量之间的距离是通过得到第n个元素的向量差的平方和的平方根来完成的。

A := (A[0], A[1], ..., A[n])
B := (B[0], B[1], ..., B[n])

distance = sqrt( (B[0]-A[0])^2 + (B[1]-A[1])^2 + ... + (B[n]-A[n])^2)

您的Pumps也可以这样做，因为它们在技术上属于属性载体。

double Dist(Pump a, Pump b)
{
    int PSIMinDiff = b.PSI_min - a.PSI_min;
    int PSIMaxDiff = b.PSI_max - a.PSI_max;
    int HorsepowerMinDiff = b.Horsepower_min - a.Horsepower_min;
    int RPMDiff = b.RPM - a.RPM;

    return Math.Sqrt(
        (PSIMinDiff * PSIMinDiff) +
        (PSIMaxDiff * PSIMaxDiff) +
        (HorsepowerMinDiff * HorsepowerMinDiff) +
        (RPMDiff * RPMDiff));
}

//Pump[] pumps   - all pumps
//Pump userPump  - the pump defined by the user

List<Pump> closestPumps = new List<Pump>();

//Get the lowest distance
double minDist = Double.MaxValue;
foreach(Pump p in pumps)
{
    double distance= Dist(p, userPump);
    if(distance < minDist) minDist = distance;
}

//Select pumps which are the closest to the one that the user defined
foreach(Pump p in pumps)
{
    if(Dist(p, userPump) == minDist)
        closestPumps.Add(p);
}

请注意，尽管此方法易于实现和使用，但其中一个最大的缺点是它没有加权，虽然结果在数学上是正确的，但它们可能与用户想要看到的不同。

找到最接近的选项

1 个答案: