We rewrite the metric/nonmetric and weighted/unweighted versions of the smacof program for square symmetric data as one monolithic C program. R is used for taking care of the data and parameter setup, the I/O, and of issuing a single call to .C() to start the computations. This makes this new smacofSS() program five to fifty times as fast (for our examples) as the smacofSym() function from the R smacof package. Utilities for various initial configurations and plots are included in the package. Examples are included to compare output and time for the R and C versions and to illustrate the various plots.
翻译:我们将适用于方阵对称数据的度量/非度量及加权/非加权版本的smacof程序重写为一个统一的C语言程序。R语言负责数据处理、参数设置、输入输出,并通过调用.C()函数启动计算。对于我们的示例,这一新的smacofSS()程序比R语言smacof包中的smacofSym()函数快五至五十倍。该程序包包含多种初始配置工具和绘图功能。我们提供了示例来比较R语言版本与C语言版本的输出结果和运行时间,并展示各类绘图功能。