r - B样条曲线绘制

要绘制r-B样条曲线，你可以使用Python中的matplotlib库。下面是一个包含代码示例的解决方法：

import numpy as np
import matplotlib.pyplot as plt

def r_b_spline(points, t):
    n = len(points) - 1
    k = 2  # degree of spline

    knots = np.concatenate((np.zeros(k), np.linspace(0, 1, n - k + 2), np.ones(k)))
    knots = np.clip(knots, 0, 1)  # ensure that knots are within [0, 1]

    def basis(i, k, t):
        if k == 0:
            return 1 if knots[i] <= t < knots[i+1] else 0
        else:
            w = (t - knots[i]) / (knots[i+k] - knots[i]) if knots[i+k] != knots[i] else 0
            return w * basis(i, k-1, t) + (1 - w) * basis(i+1, k-1, t)

    curve = np.zeros_like(t)
    for i in range(n+1):
        curve += points[i] * basis(i, k, t)

    return curve

# Define control points
points = np.array([[0, 0], [1, 3], [2, -1], [3, 2], [4, 0]])

# Generate parameter values
t = np.linspace(0, 1, 100)

# Compute the r-B spline curve
curve = r_b_spline(points, t)

# Plot the control points and the curve
plt.plot(points[:, 0], points[:, 1], 'ro-', label='Control Points')
plt.plot(curve[:, 0], curve[:, 1], 'b-', label='r-B Spline Curve')
plt.legend()
plt.show()

这段代码中，r_b_spline函数实现了r-B样条曲线的计算，其中points是控制点的坐标，t是用于生成曲线的参数值。然后使用plt.plot函数绘制了控制点和r-B样条曲线。运行代码后，你将看到包含控制点和曲线的图形窗口。