C# - 获取代表点列表

Question

我有一个方法可以在前端的 dygraph 部分中显示 returns 数千个点，它由这样的列表提供：

  List<int> pointsResult = GetMyPoints();

这张图很小，我觉得只能显示代表点。

仅获取例如 100 个值而不是数千个值的最佳方法是什么？

这个int值可以很规律，只显示代表点。

图形看起来像：

Answer 1

我找到了这个 C# 实现

A C# Implementation of Douglas-Peucker Line Approximation Algorithm

public static List<Point> DouglasPeuckerReduction
    (List<Point> Points, Double Tolerance)
{
    if (Points == null || Points.Count < 3)
    return Points;

    Int32 firstPoint = 0;
    Int32 lastPoint = Points.Count - 1;
    List<Int32> pointIndexsToKeep = new List<Int32>();

    //Add the first and last index to the keepers
    pointIndexsToKeep.Add(firstPoint);
    pointIndexsToKeep.Add(lastPoint);

    //The first and the last point cannot be the same
    while (Points[firstPoint].Equals(Points[lastPoint]))
    {
        lastPoint--;
    }

    DouglasPeuckerReduction(Points, firstPoint, lastPoint, 
    Tolerance, ref pointIndexsToKeep);

    List<Point> returnPoints = new List<Point>();
    pointIndexsToKeep.Sort();
    foreach (Int32 index in pointIndexsToKeep)
    {
        returnPoints.Add(Points[index]);
    }

    return returnPoints;
}

C# - 获取代表点列表

C# - Get a list of representative points

c#

graphing

graph-algorithm