基于一类广义Bernstein基函数定义了区间q-Bézier曲线,并研究了区间q-Bézier曲线的3种降阶逼近算法,即扰动法、基于Chebyshev多项式的最佳一致逼近法和约束最佳一致逼近法,得到3种降阶逼近方法的显式误差界,并通过实例分析了3种方法的优缺点.数值实例结果表明,与扰动法相比,最佳一致逼近法所得区间q-Bézier曲线的误差最小.
Interval q-Bézier curves are presented using a generalized Bernstein basis and the problem of degree reduction approximation of them is studied. We propose three different methods, namely, perturbation method, best uniform approximation method and constrained best uniform approximation method based on Chebyshev polynomials. The explicit representation of bounding error of each method is derived. The advantages and disadvantages of these methods are discussed by several numerical examples. These examples show that the best uniform approximation algorithm provides much tighter approximation interval curves than the perturbation method.
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