c – B样条曲线
作者:互联网
我有一组点,我想使用B样条曲线平滑.
我的问题是如何实现B样条曲线来平滑这些点?
我想用c实现这个.
解决方法:
这是任何给定点数的函数:
void Spline(double x[N+1],double y[N+1], // input
double A[N],double B[N], // output
double C[N],double D[N]) // output
{
double w[N];
double h[N];
double ftt[N+1];
for (int i=0; i<N; i++)
{
w[i] = (x[i+1]-x[i]);
h[i] = (y[i+1]-y[i])/w[i];
}
ftt[0] = 0;
for (int i=0; i<N-1; i++)
ftt[i+1] = 3*(h[i+1]-h[i])/(w[i+1]+w[i]);
ftt[N] = 0;
for (int i=0; i<N; i++)
{
A[i] = (ftt[i+1]-ftt[i])/(6*w[i]);
B[i] = ftt[i]/2;
C[i] = h[i]-w[i]*(ftt[i+1]+2*ftt[i])/6;
D[i] = y[i];
}
}
以下是如何打印此功能的结果:
void PrintSpline(double x[N+1], // input
double A[N], double B[N], // input
double C[N], double D[N]) // input
{
for (int i=0; i<N; i++)
{
cout << x[i] << " <= x <= " << x[i+1] << " : f(x) = ";
cout << A[i] << "(x-" << x[i] << ")^3 + ";
cout << B[i] << "(x-" << x[i] << ")^2 + ";
cout << C[i] << "(x-" << x[i] << ")^1 + ";
cout << D[i] << "(x-" << x[i] << ")^0";
cout << endl;
}
}
请注意,两个函数都假设x [0]< x [1]< ......< X [N].
标签:splines,c,curves,bspline 来源: https://codeday.me/bug/20190830/1768988.html