7.1 Bagging,RF&Adaboost

双重差分估计 双重差分模型（difference-in-difference，DID）近年来多用于计量经济学中对于公共政策或项目实施效果 的定量评估。 通常大范围的公共政策有别于普通科研性研究，难以保证对于政策实施组和对照组在样本分配上的完全随机。非随机分配政策实施组和对照组的试验称为自然试验（naturaltrial），此类试验存在较显著的特点，即不同组间样本在政策实施前可能存在事前差异，仅通过单一前后对比或横向对比的分析方法会忽略这种差异，继而导致对政策实施效果的有偏估计。(Quantitative evaluation of policy or project implementation effect. Generally, a wide range of public policies is different from general scientific research, and it is difficult to ensure that the sample allocation for the policy implementation group and the control group is completely random. The non-randomly assigned policy implementation group and the control group are called natural trials, which have significant characteristics, i.e. there may be prior differences between the different groups of samples before the implementation of the policy, and this difference will be ignored only through a single pre-and post-comparison or horizontal comparison analysis method, which leads to the policy. Biased estimation of implementation)

结合案例来描述每一种统计学模型，解释如何开展数据分析，讨论采用模拟手段来检验模型，这是模型开发与评估中的重要方面，给出多层回归模型（如多层ANOVA、多层线性回归和广义多层模型），指导如何用R语言采实现诸多方法，在线提供书中所用到的数据集和R语言脚本。(Combined with the case to describe each kind of statistical model, how to carry out data analysis and interpretation, discusses the use of simulation to test the model, this is an important aspect of the development and evaluation of the model, given the multi regression model (such as multilayer ANOVA, multi linear regression and generalized multi model), how to achieve a lot of mining method with the R language guide online provide the data set and the R script used in the book.)

说明：  成都市空气中的O3来源及分析，可用于大创项目(O3 source and analysis in air of Chengdu, which can be used in some projects)

SIR。。。。 传染病传播的SIR模型，很全，可直接应用仿真模拟 (SIR model the spread of infectious diseases, it is full, the simulation can be applied directly)(SIR model the spread of infectious diseases, it is full, the simulation can be applied directly)

在R中如何导入数据，主要是txt，csv，excel等数据格式的导入(how to imput data in R)

混沌控制在机电控制系统中的应用，很好的外文原版书籍。供大家学习，参考。(chaos in Electrical drive)

copula R语言，编程学习。享受copula学习的乐趣。R语言编程，copula代码(R copula)

R语言用于多元回归树分析，适用高版本的R。(Multiple regression tree analysis in R language)

说明：  金融时间序列第九章的代码加数据，用的r语言(Analysis of Financial Time Series 3th)

说明：  因子分析:包括案例和对应的R语言代码，代码中地址需要自行修改后使用(Factor analysis: including a case and corresponding R language code, the address in the code needs to be modified by itself)