[转帖]通过isight的结果数据库，有效研究优化的历程

frogfish

isight的算法很多，对不熟悉算法的人来讲就似乎是个黑盒子，觉得很神秘。那么，如何知道算法每步在干什么工作呢？<BR>下面推荐一个方法，即：通过isight的db文件数据库的后处理来研究算法的历程.<BR><BR>比如：梯度算法在计算过程中，通常要进行评价、敏度分析、线搜索等操作，你可以把db数据库打开，然后看到"Internal"这一列的值即可知道isight在这一步在作什么工作：<BR><BR>Internal： <BR>Displays the evaluation scheme used by the technique <BR>(0 - Evaluation, 1- Gradient, 2 - Search, 3 - Initialize).<BR><BR>类似的，其他字段还有如下（更多信息，请查看iSIGHT user guide的 Solution Monitor--&gt; Using Database Files --&gt; Filtering Data by Rows）：<BR><BR>Feasibility：<BR><BR>Records whether the design satisfies its constraints and how it compares to previous designs. There are ten possible values, 0-9. For more<BR>information on the meaning of these values, refer to the iSIGHT Reference Guide.<BR><BR>Control：<BR>Provides information on the iterative control mode that is being used <BR>(1 - Single, 2 - Optimize, 3 - DOE, 4 - Approximation, 5 - TaskPlan).<BR><BR>Approach：<BR>Shows whether an optimization run is deterministic or probabilistic<BR>(0 - Deterministic, 1 - Probabilistic). <BR>A deterministic optimization is a standard optimization. A probabilistic optimization includes random variables and reliability analysis.<BR><BR>Analysis：<BR>Displays the type of analysis for the recorded design point. The following options are available:<BR><BR>0 - Task run without approximations (Exact analysis).<BR>1 - Task run with approximations (Approximate analysis).<BR>2 - Design restored from database using Exact match.<BR>3 - Design restored from database using inexact match (Significant Digits match or Relative Delta match).<BR><BR>The following values are used for Mixed Integer Optimization (MOST) only. Since MOST treats all INTEGER and DISCRETE design variables as REAL parameters<BR>during initial phases of optimization, such parameters can assume values that are outside of the original design space. Therefore, design points with such violations<BR>must be marked with different Analysis codes and cannot be used for Best Solution or in future database lookups.<BR>4 - Task run without approximations (Exact analysis), outside of the original<BR>design space.<BR>5 - Task run with approximations (Approximate analysis), outside of the original design space.<BR>6 - Design restored from database using Exact match, outside of the original design space.<BR>7 - Design restored from database using inexact match (Significant Digits match or Relative Delta match), outside of the original design space.<BR><BR><BR>Technique：<BR>Displays the plan named being used during design exploration. Technique Data. Displays information pertaining to the design exploration<BR>technique.