小提琴图 (1)

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)

说明：  garch copula 带论文和code例句(garch copula with paper and code)

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)

R语言编程学习，copula函数数据编程分析。相关性分析，R语言的应用(R Copula)

说明：  进行了常微分方程的建立，并模拟出经典的SIR模型曲线(The ordinary differential equation is established and the classical SIR model curve is simulated)

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)

说明：  数据集实体文件名称：中国降水日值0.5°×0.5°格点数据集文件命名由数据集代码（SURF_CLI_CHN_PRE_DAY_GRID_0.5）、年月日标识（YYYYMMDD）组成。具体形式：SURF_CLI_CHN_PRE_DAY_GRID_0.5-YYYYMMDD.TXT(Specific form:SURF_CLI_CHN_PRE_DAY_GRID_0.5-YYYYMMDD.TXT)

说明：  制作pcoa、饼图、venn图、热图、柱状图的脚本，可直接改参数使用，内有注释，适用于微生物多样性(the Script to make PCOA)

说明：  葡萄酒数据集， 基于Wine数据集的数据分析报告 R语言+实验结果文档(Wine datasets Data Analysis Report R Language + Experimental Results Document Based on Wine Data Set)

利用R语言进行两个变量的空间自相关分析，从而进行克里金插值(The spatial autocorrelation analysis of two variables is carried out by using R language.)