/// <summary>
/// 计算链接上结点速度
/// </summary>
public void forceLink()
{
alpha = Math.Round(alpha, 15);
for (int k = 0; k < iterations; k++)
{
for (int i = 0; i < Links.Count; i++)
{
ForceLink link = Links[i];
ForceNode source = link.source, target = link.target;
double x, y, l;
//计算下一步的节点速度
x = target.x + target.vx - source.x - source.vx;
if (x == 0) //此处有疑问
{
x = jiggle();
}
y = target.y + target.vy - source.y - source.vy;
if (y == 0)
{
y = jiggle();
}
l = Math.Sqrt(x * x + y * y);
l = (l - distancesLink[i]) / l * alpha * strengthsLink[i];
x *= l;
y *= l;
double b = bias[i];
target.vx -= x * b;
target.vy -= y * b;
b = 1 - b;
source.vx += x * b;
source.vy += y * b;
}
}
}
/// <summary>
/// 析构函数
/// </summary>
/// <param name="filePath">Json文件地址</param>
/// <param name="cWidth">绘图宽度</param>
/// <param name="cHeight">绘图高度</param>
public D3force(string filePath, double cWidth, double cHeight)
{
this.cWidth = cWidth;
this.cHeight = cHeight;
StreamReader sr = new StreamReader(filePath);
string str = sr.ReadToEnd();
sr.Close();
JObject json = JObject.Parse(str);
JArray jnodes = (JArray)json["nodes"];
int i = 0;
foreach (var x in jnodes)
{
ForceNode node = new ForceNode
{
group = Convert.ToInt32(x["group"]),
id = x["id"].ToString(),
index = i,
};
Nodes.Add(node);
i++;
}
JArray jlinks = (JArray)json["links"];
int j = 0;
foreach (var x in jlinks)
{
ForceLink link = new ForceLink
{
index = j,
value = Convert.ToInt32(x["value"]),
};
string source = x["source"].ToString();
ForceNode sn = Nodes.Find(s => s.id == source);
if (sn != null)
{
link.source = sn;
}
string target = x["target"].ToString();
ForceNode tn = Nodes.Find(s => s.id == target);
if (tn != null)
{
link.target = tn;
}
Links.Add(link);
j++;
}
//初始化结点
initializeNodes();
initializeForceLink();
initializeManyBody();
}
/// <summary>
/// 获取链接的默认距离
/// </summary>
/// <param name="link">链接</param>
/// <returns>默认距离</returns>
public double defaultStrength(ForceLink link)
{
return(1 / Math.Min(count[link.source.index], count[link.target.index]));
}
