Python 如果NURBS曲线的控制点已知，如何查找节点向量？

我有一套控制点

pts = [[849, 1181],
       [916, 1257],
       [993, 1305],
       [1082,1270], 
       [1137,1181],
       [1118,1055], 
       [993,1034], 
       [873,1061], 
       [849, 1181]]

我有生成开放结向量的逻辑：

/*
Subroutine to generate a B-spline open knot vector with multiplicity
equal to the order at the ends.

c            = order of the basis function
n            = the number of defining polygon vertices
nplus2       = index of x() for the first occurence of the maximum knot       vector value
nplusc       = maximum value of the knot vector -- $n + c$
x()          = array containing the knot vector
*/

knot(n,c,x)

int n,c;
int x[];

{
    int nplusc,nplus2,i;
nplusc = n + c;
nplus2 = n + 2;

x[1] = 0;
    for (i = 2; i <= nplusc; i++){
        if ( (i > c) && (i < nplus2) )
            x[i] = x[i-1] + 1;
    else
            x[i] = x[i-1];


    }
}

/*  Subroutine to generate a B-spline uniform (periodic) knot vector.

c            = order of the basis function
n            = the number of defining polygon vertices
nplus2       = index of x() for the first occurence of the maximum knot vector value
nplusc       = maximum value of the knot vector -- $n + c$
x[]          = array containing the knot vector
*/

#include    <stdio.h>

knotu(n,c,x)

int n,c;
int x[];

{
    int nplusc,nplus2,i;

nplusc = n + c;
nplus2 = n + 2;

x[1] = 0;
for (i = 2; i <= nplusc; i++){
    x[i] = i-1;
}
}

/*
生成具有多重性的B样条开结向量的子例程
等于两端的顺序。
c=基函数的阶数
n=定义多边形顶点的数目
nplus2=第一次出现最大结向量值的x（）索引
npluc=结向量的最大值--$n+c$
x（）=包含结向量的数组
*/
结（n、c、x）
int n，c；
int x[]；
{
int NPLUC，nplus2，i；
npluc=n+c；
nplus2=n+2；
x[1]=0；
对于（i=2；ic）和（i

另一个用于生成周期结向量：

/*
Subroutine to generate a B-spline open knot vector with multiplicity
equal to the order at the ends.

c            = order of the basis function
n            = the number of defining polygon vertices
nplus2       = index of x() for the first occurence of the maximum knot       vector value
nplusc       = maximum value of the knot vector -- $n + c$
x()          = array containing the knot vector
*/

knot(n,c,x)

int n,c;
int x[];

{
    int nplusc,nplus2,i;
nplusc = n + c;
nplus2 = n + 2;

x[1] = 0;
    for (i = 2; i <= nplusc; i++){
        if ( (i > c) && (i < nplus2) )
            x[i] = x[i-1] + 1;
    else
            x[i] = x[i-1];


    }
}

/*  Subroutine to generate a B-spline uniform (periodic) knot vector.

c            = order of the basis function
n            = the number of defining polygon vertices
nplus2       = index of x() for the first occurence of the maximum knot vector value
nplusc       = maximum value of the knot vector -- $n + c$
x[]          = array containing the knot vector
*/

#include    <stdio.h>

knotu(n,c,x)

int n,c;
int x[];

{
    int nplusc,nplus2,i;

nplusc = n + c;
nplus2 = n + 2;

x[1] = 0;
for (i = 2; i <= nplusc; i++){
    x[i] = i-1;
}
}

生成B样条均匀（周期性）结向量的子例程。 c=基函数的阶数 n=定义多边形顶点的数目 nplus2=第一次出现最大结向量值的x（）索引 npluc=结向量的最大值--$n+c$ x[]=包含结向量的数组 */ #包括 纽图（北、中、西） int n，c； int x[]； { int NPLUC，nplus2，i； npluc=n+c； nplus2=n+2； x[1]=0； 对于（i=2；i节点向量（均匀与否）是NURBS曲线定义的一部分。因此，只要节点向量遵循以下基本规则，您就可以实际定义自己的非均匀节点向量：

1） #节点值=#控制点+顺序 2） 所有节点值必须是非递减的，即k[i]