GEOquery

说明：  R语言舍选法、极坐标法、Box-Muller变换产生正态随机变量(R Language Rounding Method, Polar Coordinate Method and Box-Muller Transform to Generate Normal Random Variables)

说明：  估算波动率的动态条件相关系数，衡量两个金融市场之间的风险溢出效应(Estimating the dynamic conditional correlation coefficient of volatility and measuring the Risk Spillover Effect between two financial markets)

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)

水动力模型MIKE21数据后处理 dfsu格式文件导出模拟结果xyz格式文件 R语言可以迅速批量读取xyz文件，并根据文件名排序 以便于后期处理(MIKE 21 export results from dsfu R read numerous xyz files)

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：  通过本书，读者不仅能掌握使用R及相关算法包来快速解决实际问题的方法，而且能从实际问题分析入手，到利用R进行求解，以及对挖掘结果进行分析的全面训练(Through this book, readers can not only master the method of using R and relevant algorithm packages to quickly solve practical problems, but also start from the analysis of practical problems to the comprehensive training of using R to solve problems and analyzing mining results)

实现xgboost算法，对实现分类和预测具有良好的效果(The implementation of xgboost algorithm has a good effect on classification and prediction)

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：  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)

说明：  本书提供了快速绘制高质量图形的150多种技巧，每个技巧用来解决一个特定的绘图需求。读者可以通过目录快速定位到自己遇到的问题，查询相应的解决方案。(This book provides more than 150 techniques for quickly drawing high quality graphics, each of which addresses a specific drawing requirement. Readers can quickly locate their own problems through the directory, query the corresponding solution.)