MQSI is a Fortran 2003 subroutine for constructing monotone quintic spline interpolants to univariate monotone data. Using sharp theoretical monotonicity constraints, first and second derivative estimates at data provided by a quadratic facet model are refined to produce a univariate C² monotone interpolant. Algorithm and implementation details, complexity and sensitivity analyses, usage information, a brief performance study, and comparisons with other spline approaches are included.

中文翻译：

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算法 1031：MQSI - 单调五次样条插值

MQSI 是 Fortran 2003 子程序，用于构造单调五次样条插值到单变量单调数据。使用尖锐的理论单调性约束，对二次小平面模型提供的数据的一阶和二阶导数估计进行细化以生成单变量 C ²单调插值。包括算法和实现细节、复杂性和敏感性分析、使用信息、简要性能研究以及与其他样条方法的比较。