期刊文献+
共找到5篇文章
< 1 >
每页显示 20 50 100
Selection of a Plotting Position for a Normal Q-Q Plot. R Script 被引量:2
1
作者 Castillo-Gutierrez Sonia Lozano-Aguilera Emilio Estudillo-Martinez Maria Dolores 《通讯和计算机(中英文版)》 2012年第3期243-250,共8页
关键词 Q图 脚本 位置 样本数据 概率模型 正态分布 理论分布 概率图
在线阅读 下载PDF
中国逐日气象因素的空间插值方法R代码实现
2
作者 张睿 郑环 +4 位作者 王超男 屈水令 王松旺 吴静 郭青 《环境卫生学杂志》 2025年第2期163-170,共8页
目的本研究旨在利用R代码,通过案例分析实现将气象因素站点数据插值为栅格数据,为气象因素个体暴露水平及其健康风险评估提供数据整理的方法。方法收集整理2010年1月1日至2021年12月31日,中国2419个国家级地面气象站的逐日气象数据序列... 目的本研究旨在利用R代码,通过案例分析实现将气象因素站点数据插值为栅格数据,为气象因素个体暴露水平及其健康风险评估提供数据整理的方法。方法收集整理2010年1月1日至2021年12月31日,中国2419个国家级地面气象站的逐日气象数据序列。借助R代码应用反距离加权法(inverse distance weighting,IDW)进行空间插值。结果当插值算法参数p取2、N取10~15时,可获得最佳的插值精度。同时,利用furrr包进行并行运算,开启8个CPU核心可实现最优的插值效率。结论该R代码可有效实现将气象因素站点数据插值为栅格数据。 展开更多
关键词 气象因素 个体暴露 空间插值 反距离加权法 r代码
暂未订购
Development of a Modelling Script of Time Series Suitable for Data Mining
3
作者 Víctor Sanz-Fernández Remedios Cabrera +2 位作者 Rubén Muñoz-Lechuga Antonio Sánchez-Navas Ivone A. Czerwinski 《Open Journal of Statistics》 2016年第4期555-564,共11页
Data Mining has become an important technique for the exploration and extraction of data in numerous and various research projects in different fields (technology, information technology, business, the environment, ec... Data Mining has become an important technique for the exploration and extraction of data in numerous and various research projects in different fields (technology, information technology, business, the environment, economics, etc.). In the context of the analysis and visualisation of large amounts of data extracted using Data Mining on a temporary basis (time-series), free software such as R has appeared in the international context as a perfect inexpensive and efficient tool of exploitation and visualisation of time series. This has allowed the development of models, which help to extract the most relevant information from large volumes of data. In this regard, a script has been developed with the goal of implementing ARIMA models, showing these as useful and quick mechanisms for the extraction, analysis and visualisation of large data volumes, in addition to presenting the great advantage of being applied in multiple branches of knowledge from economy, demography, physics, mathematics and fisheries among others. Therefore, ARIMA models appear as a Data Mining technique, offering reliable, robust and high-quality results, to help validate and sustain the research carried out. 展开更多
关键词 Data Mining ArIMA Models Time Series script r
在线阅读 下载PDF
QSAR Applied to 4-Chloro-3-formylcoumarin Derivatives Targeting Human Thymidine Phosphorylase
4
作者 Thomas Scior Juan Carlos Garcia-Hernandez +1 位作者 Hassan H.Abdallah Christian Alexander 《Clinical Complementary Medicine and Pharmacology》 2022年第2期19-29,共11页
Background:Coumarins are secondary metabolites from the phenylpropanoid-type biosynthesis in higher plants.A plethora of potential phytopharmacological activities have been described for derivatives of the coumarin sc... Background:Coumarins are secondary metabolites from the phenylpropanoid-type biosynthesis in higher plants.A plethora of potential phytopharmacological activities have been described for derivatives of the coumarin scaffold:hepatoprotective,antineoplastic,antimicrobial,antituberculosis,antiviral,anti-inflammatory anticoagulant,or antithrombotic effects.Objective:A computer-based quantitative structure–activity relationships(QSAR)study for a series of 4‑chloro-3-formylcoumarins was carried out.Methods:To this end we generated the 3D models of 17 published coumarin structures,calculated their physicochemical properties(descriptors)to correlate them to their experimentally known biological activities measured as inhibition concentrations to block the target enzyme activity.Our proposed approach used free molecular modeling software and applies our scripts written in the programming language R.Results:The final multiple regression models achieved satisfactory results with a small number of descriptors–all of which were statistically significant and meaningful in the field of pharmacodynamics to develop new 3-formylcoumarins with enhanced activities targeting the human thymidine phosphorylase enzyme.Conclusion:On theoretical grounds,our in silico research contributes in a crucial step in the field of complementary phyto-medicine.This step is located between in vivo pharmacological observations of plant extracts on ethnopharmacological,preclinical or controlled clinical levels and the need to identify–at an atomic scale–all those plant ingredients responsible for the biological actions under scrutiny.Our simulations shed light on the modification of phyto-medicine’s physicochemical properties to enhance the interaction with their biomolecular target in the patient’s body. 展开更多
关键词 COUMArIN Phytopharmacy r script Linear model Multiple linear regression QSAr
原文传递
gwasfilter:用于筛选全基因组关联研究的R脚本 被引量:1
5
作者 杨淞淳 李重阳 +6 位作者 胡一祯 孙秋芬 潘建桥 孙点剑一 马宝山 吕筠 李立明 《中华流行病学杂志》 CAS CSCD 北大核心 2021年第10期1876-1881,共6页
目的开发一套能高效准确地从GWAS Catalog公开数据库中筛选全基因组关联研究(GWAS)的R脚本。方法参考既往研究制定GWAS的筛选原则。将人工在GWAS Catalog的筛选过程抽象为标准的算法,2名程序员共同撰写R脚本(gwasfilter.R)后,由他人多... 目的开发一套能高效准确地从GWAS Catalog公开数据库中筛选全基因组关联研究(GWAS)的R脚本。方法参考既往研究制定GWAS的筛选原则。将人工在GWAS Catalog的筛选过程抽象为标准的算法,2名程序员共同撰写R脚本(gwasfilter.R)后,由他人多次对脚本进行测试。结果采用gwasfilter.R筛选GWAS包含6个步骤。该脚本内置5个主要函数,可以同时根据"是否有验证人群""样本量大小"和"研究人群种族"等条件对GWAS进行筛选。筛选单个性状时,程序用时不超过1秒。结论 gwasfilter.R操作简便,筛选过程高效而标准化,可灵活应用于GWAS筛选。脚本源代码网址:https://github.com/lab319/gwasfilter。 展开更多
关键词 全基因组关联研究 GWAS Catalog r脚本
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部