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R-refcard.tex
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R-refcard.tex
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% !Mode:: "TeX:UTF-8"
\documentclass[landscape]{article}
%\documentclass[10pt,portrait]{article}
\usepackage{pslatex}
\usepackage{graphicx}
\usepackage{multicol}
\usepackage{calc}
\usepackage{color}
\usepackage{amssymb, amsmath, amsfonts}
\usepackage{picins}
\usepackage{url}
\usepackage{tabularx,multicol}
\usepackage{array,booktabs,textcomp}
\renewcommand\baselinestretch{1.1} %% 全局控制行间距
\usepackage[slantfont, boldfont]{xeCJK}
%% 针对中文进行断行
\XeTeXlinebreaklocale "zh"
%% 给予TeX断行一定自由度
\XeTeXlinebreakskip = 0pt plus 1pt minus 0.1pt
%%%% xeCJK设置结束
%% 设置缺省中文字体
\setCJKmainfont{NotoSansSC-Regular}
%% 设置中文无衬线字体
%\setCJKsansfont[Scale=0.8]{宋体}
%% 设置等宽字体
\setCJKmonofont[Scale=0.7]{NotoSansSC-Regular}
%% 英文衬线字体
\setmainfont{CMU Serif}
%% 英文等宽字体
\setmonofont[Scale=0.8]{Courier New} % 对verbatim内代码格式有效
%% 英文无衬线字体
\setsansfont[Scale=1]{Candara} % 对公式有效
% Turn off header and footer
\pagestyle{empty}
%\setlength{\leftmargin}{0.75in}
\setlength{\oddsidemargin}{-0.75in}
\setlength{\evensidemargin}{-0.75in}
\setlength{\textwidth}{10.5in}
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% Redefine section commands to use less space
\makeatletter
\renewcommand\section{\@startsection{section}{1}{0mm}%
{0.5ex}% \@plus -12pt \@minus -6pt}%
{0.5ex}%
{\color{black}\normalfont\large\bfseries}}
\makeatother
% Don't print section numbers
\setcounter{secnumdepth}{0}
\setlength{\parindent}{0pt}
\setlength{\parskip}{0pt}
\newcommand{\code}{\texttt}
\newcommand{\bcode}[1]{\texttt{\textbf{#1}}}
\renewcommand{\today}{\number\year 年 \number\month 月 \number\day 日}%重定义中文日期
%\newcommand\F{\code{FALSE}}
%\newcommand\T{\code{TRUE}}
%\newcommand{\hangpara}[2]{\hangindent#1\hangafter#2\noindent}
%\newenvironment{hangparas}[2]{\setlength{\parindent}{\z@}\everypar={\hangpara{#1}{#2}}}
\newcommand{\describe}[1]{\begin{description}{#1}\end{description}}
%\definecolor{steelblue}{rgb}{.6,0,0}
\definecolor{steelblue}{rgb}{0,0,0}
% -----------------------------------------------------------------------
\begin{document}
%\raggedright
\footnotesize
\begin{multicols*}{3}
% multicol parameters
% These lengths are set only within the two main columns
%\setlength{\columnseprule}{0.25pt}
\setlength{\premulticols}{1pt}
\setlength{\postmulticols}{1pt}
\setlength{\multicolsep}{1pt}
\setlength{\columnsep}{2pt}
\begin{center}
% \Large{\textbf{\color{blue}R Reference Card}} \\
\Large{\textbf{\color{blue}R 参考卡片}} \\
\end{center}
%by Tom Short, EPRI Solutions, Inc., [email protected]
%2004-10-21 \\
%translated by SZ Liu, [email protected] 2006-09-22\\
%Granted to the public domain. See www.Rpad.org for the source and latest version.
%Includes material from \emph{R for Beginners} by Emmanuel Paradis (with permission).\\
原文档由 ~Tom Short~撰写，你可以在 \url{www.Rpad.org} 上得到最新文档。
中文版本文档 (已获得Tom Short的翻译许可)结构上同原版类似，局部添加了若干常用命令。后续修订以及维护由刘思喆负责。
%version~1.0~ 2006-09-22
项目同步在这里 \url{https://github.com/sunbjt/r_reference}
update:\today
%\section{Getting help}
\section{帮助和基础}
\everypar={\hangindent=7mm}
%Most R functions have online documentation.
大部分 R 函数都有在线文档。
%\bcode{help(topic)} documentation on \code{topic}
\bcode{help(topic)} 关于 \code{topic}的文档.
%\bcode{?topic} id.
\bcode{?topic} 同上
%\bcode{help.search("topic")} search the help system
\bcode{help.search("topic")} 搜索帮助系统
%\bcode{apropos("topic")} the names of all objects in the search list
%matching the regular expression "topic"
\bcode{apropos("topic")} 返回在搜索路径下包含(部分)关键词"topic"的所有对象名称
%\bcode{help.start()} start the HTML version of help
\bcode{help.start()} HTML形式的帮助
%\bcode{demo} Demonstrations of R Functionality
\bcode{demo()} ~R~功能演示
%\bcode{example(f)} Run an Examples Section from the Online Help
\bcode{example(f)} 运行在线帮助中的例子
%\bcode{str(a)} display the internal *str*ucture of an R object
\bcode{str(a)} 显示 R 对象的内在属性(*str*ucture)或简要说明对象
%\bcode{summary(a)} gives a 'summary' of \code{a}, usually a
%statistical summary but it is \emph{generic} meaning it has different operations for different
%classes of \code{a}
\bcode{summary(a)} 给出 \code{a}的概要, 通常是一个一般性统计概要;且它对不同属性的 \code{a} 有不同的操作方式.
%\bcode{ls()} show objects in the search path; specify \code{pat="pat"}
%to search on a pattern
\bcode{ls()} 显示'搜索路径'下的对象; 也可按指定条件搜索。
%\bcode{ls.str()} str() for each variable in the search path
\bcode{ls.str()} str() 搜索路径下的每个变量与其属性
%\bcode{dir()} show files in the current directory
\bcode{dir()} 显示当前目录下的文件
\bcode{list.files()} 同上
\bcode{getwd()} 获得工作路径信息
\bcode{setwd()} 设置工作路径
%\bcode{methods(a)} shows S3 methods of \code{a}
\bcode{methods(a)} 显示\code{a}的'S3 methods'
%\bcode{methods(class=class(a))} lists all the methods to handle objects
%of class a
\bcode{methods(class=class(a))} 列表所有可以解决属于对象类的方法
%\bcode{options(...)} set or examine many global options; common ones:
%\code{width}, \code{digits}, \code{error}
\bcode{options(...)} 设置或检验全局参数; 常用参数有:
\code{width}, \code{digits}, \code{error}
\bcode{install.packages(pkg)} 安装 pkg 包
\bcode{update.packages()} 自动对比包版本，并询问更新
%\bcode{library(x)} load add-on packages; \code{library(help=x)} lists
%datasets and functions in package \code{x}~.
\bcode{library(pkg)} 加载pkg包
\bcode{require(x)} 同上
\bcode{library(help=pkg)} 展示
包 \code{pkg} 的信息
%\bcode{attach(x)} database \code{x}~to the R search path;
%\code{x}~can be a list, data frame, or R data file created with
%\code{save}. Use \code{search()} to show the search path.
\bcode{attach(x)} 将 \code{x}~指向R的搜索路径;
\code{x}~可以使一个列表,数据框,或者是由 \code{save}创建的 R data file.
使用 \code{search()}来显示搜索路径.
%\bcode{detach(x)} \code{x}~from the R search path;
%\code{x}~can be a name or character string of an object previously
%attached or a package.
\bcode{detach(x)} \code{attach}的逆过程.
\bcode{assign(x,value)} 将\code{value}赋值给\code{x}~,即"$<-$"
\bcode{quit()} 退出当前~R~会话(q()或Ctrl\_z)
%\section{Input and output}
\section{输入与输出}
\everypar={\hangindent=9mm}
%\bcode{load()} load the datasets written with \code{save}
\bcode{load()} 加载由\code{save}命令得到的资料集
%\bcode{data(x)} loads specified data sets
\bcode{data(x)} 加载指定的数据
%\bcode(edit())Invoke a text editor on an R object.
\bcode{edit()} 调用文本编辑器修改R对象
%\bcode{fix(x)} 'fix' invokes 'edit' on 'x' and then assigns the new (edited)
% version of 'x' in the user's workspace.
\bcode{fix(x)} 'fix' 调用 'edit' 修改 'x'
\bcode{data.entry(x)} 电子数据表形式的录入编辑器
\bcode{scan(x)} 从控制台或文件中读取数据为向量或列表
%\bcode{library(x)} load add-on packages
%\bcode{library(x),require(x)} 加载额外的包
%\bcode{read.table(file)} reads a file in table format and
% creates a data frame from it; the default separator
% \code{sep=""} is any whitespace; use \code{header=TRUE}
% to read the first line as a header of column names; use \code{as.is=TRUE} to
% prevent character vectors from being converted to
% factors; use \code{comment.char=""} to prevent
% \code{"\#"} from being interpreted as a comment; use
% \code{skip=n} to skip \code{n} lines before reading data; see
% the help for options on row naming, NA treatment, and
% others
\bcode{read.table(file)} 读取表格式的文件并将其创建成数据框;默认分割符
\code{sep=""}为任意空白;使用\code{header=TRUE}
读取第一行作为列标题;使用\code{as.is=TRUE}防止字符向量变为
factors;使用\code{comment.char=""}防止\code{"\#"}被解释为注释;
使用\code{skip=n} 在读数据前跳过 \code{n} 行;详细见帮助关于行
命名,NA 处理,和其他
%\bcode{read.csv("filename",header=TRUE)} id. but with defaults set for reading
%comma-delimited files
\bcode{read.csv("filename",header=TRUE)} 同上,但默认设置为读取~\code{csv} 文件(Comma Separated values)
%\bcode{read.delim("filename",header=TRUE)} id. but with defaults set for reading
%tab-delimited files
\bcode{read.delim("filename",header=TRUE)} 同上,默认设置为读取 \code{tab} 分割文件
%\bcode{read.fwf(file,widths,header=FALSE,sep="\t",as.is=FALSE)} read a table of
%\emph{f}ixed \emph{w}idth \emph{f}ormatted data into a
% 'data.frame'; \code{widths} is an integer vector, giving the widths of the fixed-width fields
\bcode{read.fwf(file,widths,header=F,sep="$\backslash$t",as.is=FALSE)} \\
以fixed width formatted形式读取数据
至数据框; \code{widths} 是整数向量, 用于设置调整宽度字段
%\bcode{save(file,...)} saves the specified objects (...) in the XDR
%platform-independent binary format
\bcode{save(file,...)} 以不分平台的二进制保存指定的对象
%\bcode{save.image(file)} saves all objects
\bcode{save.image(file)} 保存所有的对象
\bcode{dump("x","...")} 将对象~x~保存在'...'里
%\bcode{cat(..., file="", sep=" ")} prints the arguments after coercing to
%character; \code{sep} is the character separator between arguments
\bcode{cat(..., file="", sep=" ")} 强制转化为字符后打印 对象的赋值;
\code{sep} 为对象赋值间的分割符号
%\bcode{print(a, ...)} prints its arguments; generic, meaning it can
%have different methods for different objects
\bcode{print(a, ...)} 显示\code{a}的赋值，更一般的，它对于不同的对象可以有不同的表达方式。
%\bcode{format(x,...)} format an R object for pretty printing
\bcode{format(x,...)} 格式化,更好的显示 R 对象
%\bcode{write.table(x,file="",row.names=TRUE,col.names=TRUE, sep=" ")}
%prints \code{x}~after converting to a data frame; if \code{quote} is
% \code{TRUE}, character or factor columns are
% surrounded by quotes (\code{"}); \code{sep} is the field
% separator; \code{eol} is the end-of-line separator;
% \code{na} is the string for missing values; use
% \code{col.names=NA} to add a blank column header to
% get the column headers aligned correctly for
% spreadsheet input
\bcode{write.table(x,file="",row.names= T ,col.names= T , sep="")}
在把\code{x}~转化为数据框后,写到文件; 如果 \code{quote} 为
\code{TRUE}, 字符和因子列就会被 (\code{"})所包围; \code{sep} 是字段分隔符
; \code{eol} 为尾行分割符;
\code{na} 为缺失值字符串; 使用
\code{col.names=NA} 增加列标题以便于和表格输入一致
%\bcode{sink(file)} output to \code{file}, until \code{sink()}
\bcode{sink(file)} 输出到文件\code{file}, 直到输入命令 \code{sink()}
\everypar={\hangindent=9mm}
%Most of the I/O functions have a \code{file} argument. This can often
%be a character string naming a file or a connection. \code{file=""} means the standard input or
%output. Connections can include files, pipes, zipped
%files, and R variables.
\vspace{2mm}
大部分~$I/O$~函数都有 \code{file} 参量.它经常用一个字符串来命名文件或连接. \code{file=""} 意味着标准输入或输出.
连接(Connections)可以包含文件(file),管道(pipes),压缩文件(zipped files)或~R~变量
%On windows, the file connection can also be used with \code{description =
%"clipboard"}. To read a table copied from Excel, use \\
%\code{x <- read.delim("clipboard")}\\
%To write a table to the clipboard for Excel, use \\
%\code{write.table(x,"clipboard",sep="\textbackslash t",col.names=NA)}
在~windows~操作环境下，数据共享可以通过写字板（clipboard）的方式.读取~Excel~表：可以将~Excel~中数据拷贝至写字板
（内存）,使用 \code{x <- read.delim('clipboard')} 方式读取数据。
\code{write.table(x, 'clipboard', sep='\t',col.names=NA)}可以将数据写入clipboard,可直接粘贴到Excel中。
%For database interaction, see packages \code{RODBC}, \code{DBI},
%\code{RMySQL}, \code{RPgSQL}, and \code{ROracle}. See packages \code{XML}, \code{hdf5}, \code{netCDF} for reading
%other file formats.
数据库方面的交互应用,请见 \code{RODBC}, \code{DBI},\code{RMySQL}, \code{RPgSQL}, and \code{ROracle}包.
读取其他文件格式参考 \code{XML}, \code{hdf5}, \code{netCDF} 等包.
%\section{Data creation}
\section{数据创建}
\everypar={\hangindent=9mm}
%\bcode{c(...)} generic function to combine arguments with the default
%forming a vector;
%with \code{recursive=TRUE} descends through lists combining all elements
%into one vector
\bcode{c(...)} 常见的将一系列参量转化为向量的函数;
通过 \code{recursive=TRUE} 降序排列列表并组合所有的元素为向量.
%\bcode{from:to} generates a sequence; ':' has operator priority; 1:4
%+ 1 is '2,3,4,5'
\bcode{from:to} 产生一个序列; ':' 有较高级别的优先级; 1:4
+ 1 得到 '2,3,4,5'
%\bcode{seq(from,to)} generates a sequence
\bcode{seq(from,to)} 产生一个序列
%\code{by=} specifies increment; \code{length=} specifies desired length
\code{by=} 指定间距; \code{length=} 指定要求长度
%\bcode{seq(along=x)} generates \code{1, 2, ..., length(along)}; useful for
%\code{for} loops
\bcode{seq(along=x)} 产生 \code{1, 2, ..., length(along)}; 常用在循环上
%\bcode{rep(x,times)} replicate \code{x}~\code{times}; use \code{each=}
%to repeat 'each' element of \code{x}~\code{each} times;
%\code{rep(c(1,2,3),2)} is 1 2 3 1 2 3; \code{rep(c(1,2,3),each=2)} is 1 1 2 2 3 3
\bcode{rep(x,times)} 重复 \code{x}~\code{times}次; 使用 \code{each=}
来指定元素 \code{x}~重复的次数;\code{rep(c(1,2,3),2)} 将得到 1 2 3 1 2 3;
\code{rep(c(1,2,3),each=2)} 将得到 1 1 2 2 3 3
%\bcode{data.frame(...)} create a data frame of the named or unnamed arguments;
% \code{data.frame(v=1:4,ch=c("a","B","c","d"),n=10)}; shorter vectors
% are recycled to the length of the longest
\bcode{data.frame(...)} 创建数据框,当然变量可能被命名或不被命名;
\code{data.frame(v=1:4,ch=c("a","B","c","d"),n=10)}; 相对较短的向量会被循环填充到
最长向量长度
%\bcode{list(...)} create a list of the named or unnamed arguments;
% \code{list(a=c(1,2),b="hi",c=3i)};
\bcode{list(...)} 创建一个由变量组成的列表,变量可能被命名或未被命名;
\code{list(a=c(1,2),b="hi",c=3i)};
%\bcode{array(x,dim=)} array with data \code{x}~; specify
%dimensions like \code{dim=c(3,4,2)}; elements of \code{x}~recycle if \code{x}~%is not long enough
\bcode{array(x,dim=)} 产生由\code{x}~组成的数组;使用类似\code{dim=c(3,4,2)}指定维数;
如果\code{x}~不够长度,则\code{x}~自动循环
%\bcode{matrix(x,nrow=,ncol=)} matrix; elements of \code{x}~recycle
\bcode{matrix(x,nrow=,ncol=)} 矩阵;同上
%\bcode{factor(x,levels=)} encodes a vector \code{x}~as a factor
\bcode{factor(x,levels=)} 把向量 \code{x}~编码成为因子
%\bcode{gl(n,k,length=n*k,labels=1:n)} generate levels (factors) by specifying
%the pattern of their levels; \code{k} is the number of levels, and \code{n} is the
%number of replications
\bcode{gl(n,k,length=n*k,labels=1:n)} 通过指定水平方式产生水平(因子); \code{k} 为水平的个数;
\code{n} 为重复的次数
%\bcode{expand.grid()} a data frame from all combinations of the supplied vectors
% or factors
\bcode{expand.grid()} 提供的向量或因子所有组合构成的数据框
%\bcode{rbind(...)} combine arguments by rows for matrices, data frames, and others
\bcode{rbind(...)} 把以行的形式组合矩阵,数据框,或其他
%\bcode{cbind(...)} id. by columns
\bcode{cbind(...)} 同上.以列的形式
%\section{Slicing and extracting data}
\section{数据分割和选取}
\everypar={\hangindent=9mm}
%Indexing vectors
\textcolor{steelblue}{向量索引}
\begin{tabular}{rr}
%\code{x[n]} & \code{n}$^{th}$ element\\
\code{x[n]} & 第\code{n}个元素\\
%\code{x[-n]} & all \emph{but} the \code{n}$^{th}$ element\\
\code{x[-n]} & 除了第\code{n}个元素的\code{x}~\\
%\code{x[1:n]} & first \code{n} elements\\
\code{x[1:n]} & 前\code{n}个元素\\
%\code{x[-(1:n)]} & elements from \code{n+1} to the end\\
\code{x[-(1:n)]} & 第 \code{n+1} 至最后的元素\\
%\code{x[c(1,4,2)]} & specific elements\\
\code{x[c(1,4,2)]} & 指定元素\\
%\code{x["name"]} & element named \code{"name"}\\
\code{x["name"]} & 名为\code{"name"}的元素\\
%\code{x[x > 3]} & all elements greater than 3\\
\code{x[x > 3]} & 所有大于3的元素\\
%\code{x[x > 3 \& x < 5]} & all elements between 3 and 5\\
\code{x[x > 3 \& x < 5]} & 区间(3,5)的元素\\
%\code{x[x \%in\% c("a","and","the")]} & elements in the given set\\
\code{x[x \%in\% c("a","and","the")]} & 给定组中的元素\\
\end{tabular}
%Indexing lists\\*
\textcolor{steelblue}{列表索引}\\*
%\samepage
\vspace{-3mm}
\begin{tabular}{@{}l@{\ }l}
%\code{x[n]} & list with elements \code{n}\\
\code{x[n]} & 列表显示元素\code{n}\\
%\code{x[[n]]} & \code{n}$^{th}$ element of the list\\
\code{x[[n]]} & 列表的第\code{n}个元素\\
%\code{x[["name"]]} & element of the list named \code{"name"}\\
\code{x[["name"]]} & 名为\code{"name"}的元素\\
%\code{x\$name} & id.\\
\code{x\$name} & 同上.\\
\end{tabular}
%Indexing matrices
\textcolor{steelblue}{矩阵索引}
\begin{tabular}{@{}l@{\ }l}
%\code{x[i,j]} & element at row \code{i}, column \code{j}\\
\code{x[i,j]} & 下标为(i,j)的元素\\
%\code{x[i,]} & row \code{i}\\
\code{x[i,]} & 第\code{i}行\\
%\code{x[,j]} & column \code{j}\\
\code{x[,j]} & 第\code{j}列\\
%\code{x[,c(1,3)]} & columns 1 and 3\\
\code{x[,c(1,3)]} & 第1和3列\\
%\code{x["name",]} & row named \code{"name"}\\
\code{x["name",]} & 名为\code{"name"}的行\\
\end{tabular}
%Indexing data frames (matrix indexing plus the following)
\textcolor{steelblue}{数据框索引(\emph{矩阵索引加下述})}
\begin{tabular}{@{}l@{\ }l}
\code{x[["name"]]} & 列名为 \code{"name"}的列\\
\code{x\$name} & 同上.\\
\end{tabular}
%\section{Variable conversion}
\section{变量变换}
\everypar={\hangindent=9mm}
\bcode{as.array(x), as.data.frame(x), as.numeric(x), }
\bcode{as.logical(x), as.complex(x), as.character(x),} 等, \\
转换变量类型; 使用如下命令得到全部列表:
\code{methods(as)}
%\section{Variable information}
\section{变量信息}
\everypar={\hangindent=9mm}
\bcode{is.na(x), is.null(x), is.array(x), is.data.frame(x),}
\bcode{is.numeric(x), is.complex(x), is.character(x), ...} 检验变量类型;
使用如下命令得到全部列表, \code{methods(is)}
%\bcode{length(x)} number of elements in \code{x}~\bcode{length(x)} \code{x}~中元素的个数
%\bcode{dim(x)} Retrieve or set the dimension of an object;
\bcode{dim(x)} 重新设置或设置对象的维数;
\code{dim(x) <- c(3,2)}
%\bcode{dimnames(x)} Retrieve or set the dimension names of an object
\bcode{dimnames(x)} 重新设置或设置对象的名称
%\bcode{nrow(x)} number of rows; \code{NROW(x)} is the same but treats
%a vector as a one-row matrix
\bcode{nrow(x)} 和 \bcode{NROW(x)} 返回行的个数\code{dim(x)[1]}
%\bcode{ncol(x)} and \bcode{NCOL(x)} id. for columns
\bcode{ncol(x)} 和 \bcode{NCOL(x)} 返回列的个数\code{dim(x)[2]}
%\bcode{class(x)} get or set the class of \code{x}~; \code{class(x) <- "myclass"}
\bcode{class(x)} 得到或设置\code{x}~的类;\code{class(x) <- "myclass"}
%\bcode{unclass(x)} remove the class attribute of \code{x}~\bcode{unclass(x)} 删除\code{x}~的类
%\bcode{names(x)} Functions to get or set the names of an object.
\bcode{names(x)} 查看或设置对象名称(names)
%\bcode{unname(x)} Remove the 'names' or 'dimnames' attribute of an R object.
\bcode{unname(x)} 删除~R~对象的名称(names)或维名称(dimnames)
%\bcode{unlist(x)} Given a list structure 'x', 'unlist' simplifies it to produce a
% vector which contains all the atomic components which occur in 'x'.
\bcode{unlist(x)} 将列表~x~转化为向量
%\bcode{attr(x,which)} get or set the attribute \code{which} of \code{x}~\bcode{attr(x,which)} 得到或设置 \code{x}~的属性类型 \code{which}~
%\bcode{attributes(obj)} get or set the list of attributes of \code{obj}
\bcode{attributes(obj)} 得到或设置 \code{obj} 的属性列表
%\section{Data selection and manipulation}
\section{数据选择和操作}
\everypar={\hangindent=9mm}
%\bcode{which.max(x)} returns the index of the greatest element of
%\bcode{x}
\bcode{which.max(x)} 返回\bcode{x}中最大元素的索引
%\bcode{which.min(x)} returns the index of the smallest element of
%\bcode{x}
\bcode{which.min(x)} 返回\bcode{x}中最小元素的索引
%\bcode{rev(x)} reverses the elements of \code{x}~\bcode{rev(x)} 颠倒 \code{x}~中所有的元素
%\bcode{rle{x}} *R*un *L*ength *E*ncoding
\bcode{rle(x)} 返回游程（Runs）信息
%\bcode{sort(x)} sorts the elements of \code{x}~in increasing order; to sort in decreasing order: \code{rev(sort(x))}
\bcode{sort(x)} 升序排列\code{x}~中的元素;降序排列使用:\code{rev(sort(x))}
%\bcode{cut(x,breaks)} divides \code{x}~into intervals (factors);
%\code{breaks} is the number of cut intervals or a vector of cut points
\bcode{cut(x,breaks)} 将 \code{x}~分割成为几段(或因子); \code{breaks}为分割的段数或分割点向量.
%\bcode{match(x, y)} returns a vector of the same length than \code{x}~with the elements of \code{x}~%which are in \code{y} (\code{NA} otherwise)
\bcode{match(x, y)} 返回一个和 \code{x}~相同长度且和 \code{y}~中元素相等的向量,（不等的元素返回\code{NA}~）
%\bcode{which(x == a)} returns a vector of the indices of \code{x}~if the comparison operation is true (\T),
%in this example the values of \code{i} for which \code{x[i] == a}
%(the argument of this function must be a variable of mode logical)
\bcode{which(x == a)} 如果比较操作为真（\T）,返回向量 \code{x}~的索引
%\bcode{choose(n, k)} computes the combinations of $k$ events among $n$ repetitions = $n!/[(n-k)!k!]$
\bcode{choose(n, k)} 组合数=$n!/[(n-k)!k!]$
\bcode{sign(x)} 判断变量是否大于0,大于返回“1”,小于返回“-1”,等于返回“0”
%\bcode{na.omit(x)} suppresses the observations with missing data (\code{NA})
%(suppresses the corresponding line if \code{x}~is a matrix or a data frame)
\bcode{na.omit(x)} 去除缺失值（\code{NA}）,如果 \code{x}~为矩阵或数据框,去除相关行
%\bcode{na.fail(x)} returns an error message if \code{x}~contains at least one \code{NA}
\bcode{na.fail(x)} 返回错误信息如果 \code{x}~包含至少一个 \code{NA}
%\bcode{unique(x)} if \code{x}~is a vector or a data frame,
%returns a similar object but with the duplicate elements suppressed
\bcode{unique(x)} 如果\code{x}~为向量或数据框,返回惟一值
\bcode{duplicated(x)} 返回向量或数据框 \code{x}~重复元素的逻辑值
%\bcode{table(x)} returns a table with the numbers of the differents values of \code{x}~(typically for integers or factors)
\bcode{table(x)} 返回一个由 \code{x}~不同值个数组成的表格(常用于整数或因子),即频数表
%\bcode{subset(x, ...)} returns a selection of \code{x}~with respect to criteria (\code{...},
%typically comparisons: \code{x\$V1 < 10}); if \code{x}~is a data frame,
%the option \code{select} gives the variables to be kept or dropped using a minus sign
\bcode{subset(x, ...)} 根据条件（\code{...}选取\code{x}~中的元素,如:\code{x\$V1 < 10}）;
如果\code{x}~为数据框,选项\code{select} 通过使用负号的方式保留或去除变量
%\bcode{sample(x, size)} resample randomly and without replacement \code{size} elements in the vector \code{x}~,
%the option \code{replace = TRUE} allows to resample with replacement
\bcode{sample(x, size)} 不放回的随机在向量\code{x}~中抽取\code{size}个元素,选项\code{replace = TRUE}允许放回抽取
%\bcode{prop.table(x,margin=)} table entries as fraction of marginal table
\bcode{prop.table(x,margin=)} 根据 \code{margin} 使用分数表示表格,无 \code{margin} 时,所有元素和为1
%\section{Math}
\section{数学}
\everypar={\hangindent=9mm}
%\bcode{sin,cos,tan,asin,acos,atan,atan2,log,log10,exp}
\bcode{+,-,$\times$,$\div$,\^{},\%\%,\%/\%}
\bcode{< > <= >= ==..!=..} %add
\bcode{sin,cos,tan,asin,acos,atan,atan2,log,log10,exp}
%\bcode{max(x)} maximum of the elements of \code{x}~\bcode{max(x)} 返回\code{x}~最大的元素
%\bcode{min(x)} minimum of the elements of \code{x}~\bcode{min(x)} 同上.最小
%\bcode{range(x)} id. then \code{c(min(x), max(x))}
\bcode{range(x)} 返回\code{c(min(x), max(x))}
%\bcode{sum(x)} sum of the elements of \code{x}~\bcode{sum(x)} \code{x}~中各元素的加和
%\bcode{diff(x)} lagged and iterated differences of vector \code{x}~\bcode{diff(x)} 向量\code{x}~的差分
%\bcode{prod(x)} product of the elements of \code{x}~\bcode{prod(x)} \code{x}~中元素连乘
%\bcode{mean(x)} mean of the elements of \code{x}~\bcode{mean(x)} \code{x}~的均值
\bcode{abs(x)} x的绝对值
\bcode{sqrt(x)} $x^{0.5}$
%\bcode{median(x)} median of the elements of \code{x}~\bcode{median(x)} \code{x}~的中位数
%\bcode{quantile(x,probs=)} sample quantiles
% corresponding to the given probabilities (defaults to 0,.25,.5,.75,1)
\bcode{quantile(x,probs=)} 样本分位数,默认为0,0.25,0.75,1
%\bcode{IQR(x)} computes interquartile range of the 'x' values.
\bcode{IQR(x)} 返回数据中间50\%的区间
%\bcode{weighted.mean(x, w)} mean of \code{x}~with weights \code{w}
\bcode{weighted.mean(x, w)} 加权平均
%\bcode{rank(x)} ranks of the elements of \code{x}~\bcode{rank(x)} \code{x}~中元素的秩
%\bcode{var(x)} or \code{cov(x)} variance of the elements of \code{x}~%(calculated on $n-1$); if \code{x}~is a matrix or a data frame, the
%variance-covariance matrix is calculated
\bcode{var(x)} or \code{cov(x)} 向量\code{x}~的样本方差; 如果\code{x}~是矩阵或
数据框,协方差矩阵将被计算
%\bcode{sd(x)} standard deviation of \code{x}~\bcode{sd(x)} \code{x}~的标准差; sd(x)=sqrt(var(x))
%\bcode{cor(x)} correlation matrix of \code{x}~if it is a matrix or a
%data frame (1 if \code{x}~is a vector)
\bcode{cor(x)} 如果\code{x}~是矩阵或数据框,返回相关阵(1 如果\code{x}~为向量)
%\bcode{var(x, y)} or \code{cov(x, y)} covariance between \code{x}~and \code{y},
%or between the columns of \code{x}~and those of \code{y} if they are matrices or data frames
\bcode{var(x, y)} or \code{cov(x, y)} \code{x}~和\code{y} 间的协方差;
如果\code{x}~,\code{y} 为矩阵或数据框,返回\code{x}~和\code{y} 各列的协方差
%\bcode{cor(x, y)} linear correlation between \code{x}~and \code{y},
%or correlation matrix if they are matrices or data frames
\bcode{cor(x, y)} \code{x}~和\code{y} 线性相关系数;或者相关阵,如果\code{x}~和\code{y} 为矩阵或数据框
%\bcode{round(x, n)} rounds the elements of \code{x}~to \code{n} decimals
\bcode{round(x, n)} \code{x}~的约数,精确到\code{n} 位
%\bcode{log(x, base)} computes the logarithm of \code{x}~with base \code{base}
\bcode{log(x, base)} 计算\code{x}~以\code{base}为底的对数,$e=\code{exp(1)}$
%\bcode{scale(x)} if \code{x}~is a matrix, centers and reduces the data;
%to center only use the option \code{center=FALSE},
%to reduce only \code{scale=FALSE} (by default \code{center=TRUE, scale=TRUE})
\bcode{scale(x)} 如果 \code{x}~是一个矩阵,则中心化和标准化数据;若只标准化则使用选项 \code{center=FALSE},
若只中心化使用 \code{scale=FALSE} (默认 \code{center=TRUE, scale=TRUE})
\bcode{integrate(f,lower,upper)} 函数~f~在区间(lower,upper)的面积(积分)
%\bcode{pmin(x,y,...)} a vector which $i$th element is the minimum of \code{x[i]}, \code{y[i]}, \ldots
\bcode{pmin(x,y,...)} \code{x[i]}, \code{y[i]}相比较小者,组成新的向量
%\bcode{pmax(x,y,...)} id. for the maximum
\bcode{pmax(x,y,...)} 同上.较大者
%\bcode{cumsum(x)} a vector which $i$th element is the sum from \code{x[1]} to \code{x[i]}
\bcode{cumsum(x)} 由\code{x}~组成的向量,\code{x[i]}=sum\{\code{x[1]}:\code{x[i]}\}
%\bcode{cumprod(x)} id. for the product
\bcode{cumprod(x)} 同上.连乘
%\bcode{cummin(x)} id. for the minimum
\bcode{cummin(x)} 同上.最小
%\bcode{cummax(x)} id. for the maximum
\bcode{cummax(x)} 同上.最大
%\bcode{union(x,y)},~\bcode{intersect(x,y)},~\bcode{setdiff(x,y)},~\bcode{setequal(x,y)},
%\bcode{is.element(el,set)} 'set' functions
%\bcode{union(x,y)},~\bcode{intersect(x,y)},~\bcode{setdiff(x,y)},~\bcode{setequal(x,y)},
%\bcode{is.element(el,set)} 'set' 函数
\bcode{union(x,y)} $x \cup y - x \cap y$
\bcode{intersect(x,y)} $x \cap y$
\bcode{setdiff(x,y)} $x - x \cap y$
\bcode{setequal(x,y)} 返回比较 \code{x}~, \code{y} 是否相同的逻辑值(\code{x}~,\code{y}不涉及顺序).
\bcode{is.element(el,set)} 同 x \%in\% y
%\bcode{Re(x)} real part of a complex number
\bcode{Re(x)} 复数的实部
%\bcode{Im(x)} imaginary part
\bcode{Im(x)} 虚部
%\bcode{Mod(x)} modulus; \code{abs(x)} is the same
\bcode{Mod(x)} 绝对值(模);同\code{abs(x)}
%\bcode{Arg(x)} angle in radians of the complex number
\bcode{Arg(x)} 复数角度(in radians)
%\bcode{Conj(x)} complex conjugate
\bcode{Conj(x)} 求 ~x~的共轭复数
%\bcode{convolve(x,y)} compute the several kinds of
% convolutions of two sequences
\bcode{convolve(x,y)} 计算两个序列的卷积
%\bcode{fft(x)} Fast Fourier Transform of an array
\bcode{fft(x)} 排列(array)的快速傅立叶变换
%\bcode{mvfft(x)} FFT of each column of a matrix
\bcode{mvfft(x)} 矩阵各列的快速傅立叶变换
%\bcode{filter(x,filter)} applies linear filtering to a univariate time series or to each
% series separately of a multivariate time series
\bcode{filter(x,filter)} 对但变量时间序列或多变量时间序列的单独序列进行线性过滤
\everypar={\hangindent=0mm}
%Many math functions have a logical parameter \code{na.rm=FALSE} to
%specify missing data (NA) removal.
大多数学函数使用逻辑参数\code{na.rm=FALSE} 来指定是否移除缺失值(NA).
%\section{Matrices}
\section{矩阵}
\everypar={\hangindent=9mm}
%\bcode{t(x)} transpose
\bcode{t(x)} 转置
%\bcode{diag(x)} diagonal
\bcode{diag(x)} 对角阵
%\bcode{\%*\%} matrix multiplication
\bcode{\%*\%} 矩阵运算
%\bcode{solve(a,b)} solves \code{a \%*\% x = b} for \code{x}~\bcode{solve(a,b)} 运算 \code{a \%*\% x = b} 得到\code{x}~
%\bcode{solve(a)} matrix inverse of \code{a}
\bcode{solve(a)} 矩阵的逆
%\bcode{eigen(x)} Computes eigenvalues and eigenvectors of real or complex matrices.
\bcode{eigen(x)} 计算矩阵的特征根和特征向量
%\bcode{rowsum(x)} sum of rows for a matrix-like object;
%\bcode{rowSums(x)} is a faster version
\bcode{rowsum(x)} 矩阵格式对象行加和;
\bcode{rowSums(x)} 是一个更快的版本
%\bcode{colsum(x)}, \bcode{colSums(x)} id. for columns
\bcode{colsum(x)}, \bcode{colSums(x)} 同上.列
%\bcode{rowMeans(x)} fast version of row means
\bcode{rowMeans(x)} 行平均
%\bcode{colMeans(x)} id. for columns
\bcode{colMeans(x)} 列平均
%\bcode{dist{x}} This function computes and returns the distance matrix computed by
% using the specified distance measure to compute the distances
% between the rows of a data matrix.
\bcode{dist(x)} 计算矩阵 \code{x}~行间的距离
%\section{Advanced data processing}
\section{高级数据处理}
\everypar={\hangindent=9mm}
%\bcode{apply(X,INDEX,FUN=)} a vector or array or list of values obtained by applying a
% function \code{FUN} to margins (\code{INDEX}) of \code{x}~\bcode{apply(X,INDEX,FUN=)} 根据数组的下标(\code{INDEX}) 应用函数 \code{FUN} 返回向量,数组或列表的值
%\bcode{lapply(X,FUN)} apply \code{FUN} to each element of the list \code{x}~\bcode{lapply(X,FUN)} 应用 \code{FUN} 到列表 \code{x}~的每个元素
%\bcode{tapply(X,INDEX,FUN=)} apply \code{FUN} to each cell
%of a ragged array given by \code{x}~with indexes \code{INDEX}
\bcode{tapply(X,INDEX,FUN=)} 根据 \code{x}~的索引 (INDEX) 对不完全(ragged)的数列应用 \code{FUN}
\bcode{sapply} 同 \code{lapply},比之更友好
%\bcode{by(data,INDEX,FUN)} apply \code{FUN} to data frame \code{data}
%subsetted by \code{INDEX}
\bcode{by(data,INDEX,FUN)} 应用函数 \code{FUN} 处理数据框 \code{data} 中由 \code{INDEX} 定义的子集
%\bcode{merge(a,b)} merge two data frames by common columns or row names
\bcode{merge(a,b)} 根据共有的列或行名把两个数据框合并
%\bcode{xtabs(a~b,data=x)} a contingency table from cross-classifying factors
\bcode{xtabs(a~b,data=x)} 从交叉分类因子得到列联表
%\bcode{aggregate(x,by,FUN)} splits the data frame \code{x}~into subsets, computes summary statistics for
% each, and returns the result in a convenient form; \code{by} is a
% list of grouping elements, each as long as the variables in \code{x}~\bcode{aggregate(x,by,FUN)} 将数据框 \code{x}~分割为几个子集, 且计算各个子集的概要统计,
并且以合适的方式返回结果; \code{by}是分组元素列表
%\bcode{stack(x, ...)} transform data available as
% separate columns in a data frame or list into a single column
\bcode{stack(x, ...)} 将分开列形式的数据框或列表中的数据变量转化为单列
%\bcode{unstack(x, ...)} inverse of \code{stack()}
\bcode{unstack(x, ...)} \code{stack()}的逆过程
%\bcode{reshape(x, ...)} reshapes a data frame between 'wide' format with
% repeated measurements in separate columns of the same record and
% 'long' format with the repeated measurements in separate records;
% use \code(direction="wide") or \code(direction="long")
\bcode{reshape(x, ...)} 对'wide'和'long'格式对数据框进行改造.
'wide'格式是根据基准变量横向扩展数据框；
'long'格式是根据基准变量纵向扩展数据框.
使用 \code(direction='wide') 或 \code(direction='long') 参数指定格式.
\bcode{expression(expr)} 创建或检验对象是否为表达(expression)形式. 参考 is.expression(x), as.expression(x, ...)
\bcode{parse(file = "", n = NULL)} 以列表形式返回解析过, 但没有经过计算的表达(expression)
%\bcode{deparse(expr)}
\bcode{eval(expr)} 在指定的环境下计算~R~表达(expression)
%\section{Strings}
\section{字符}
\everypar={\hangindent=9mm}
%\bcode{paste(...)} concatenate vectors after converting to character;
%\code{sep=} is the string to separate terms (a single space is the default);
%\code{collapse=} is an optional string to separate 'collapsed' results
\bcode{paste(...)} 转化为字符后连接向量;\code{sep =} 为分割界限 (一个空格为默认);
选择\code{collapse =} 可以分割'collapsed'结果
%\bcode{substr(x,start,stop)} substrings in a character vector; can also assign,
%as \code{substr(x, start, stop) <- value}
\bcode{substr(x,start,stop)} 提取字符向量的子字段;同样可以赋值,使用\code{substr(x, start, stop) <- value}
%\bcode{strsplit(x,split)} split \code{x}~according to the substring \code{split}
\bcode{strsplit(x,split)} 在\code{split} 的位置分割\code{x}~
%\bcode{grep(pattern,x)} searches for matches to \code{pattern}
% within \code{x}~; see \code{?regex}
\bcode{grep(pattern,x)} \code{pattern}条件的匹配和替换;参见\code{?regex}
%\bcode{gsub(pattern,replacement,x)} replacement of matches determined by
%regular expression matching \code{sub()} is the same but only
%replaces the first occurrence.
\bcode{gsub(pattern,replacement,x)} 替换满足正则表达式的字段,\code{sub()} 类似,但只替换第一个出现的字段
%\bcode{tolower(x)} convert to lowercase
\bcode{tolower(x)} 将字母转化为小写
%\bcode{toupper(x)} convert to uppercase
\bcode{toupper(x)} 将字母转化为大写
%\bcode{casefold(x, upper = TRUE)} translate to upper or lower case?.
\bcode{casefold(x, upper = TRUE)} 变化 \code{x}~为大写(TRUE)或小写(FALSE)
\bcode{chartr(old, new, x)} 将\code{x}~中的字符 \code{old} 变换为字符 \code{new}
%\bcode{match(x,table)} a vector of the positions of first matches for the elements of \code{x}~among \code{table}
\bcode{match(x,table)} \code{table} 中匹配\code{x}~元素位置组成的向量.
%\bcode{x \%in\% table} id. but returns a logical vector
\bcode{x \%in\% table} 同上.返回逻辑向量
%\bcode{pmatch(x,table)} partial matches for the elements of \code{x}~among \code{table}
\bcode{pmatch(x,table)} \code{table} 中部分匹配\code{x}~元素
%\bcode{nchar(x)} number of characters
\bcode{nchar(x)} 字符的个数
%\vspace{6pt}
%\section{\color{black}Dates and Times}
\section{\color{black}日期和时间}
%The class \code{Date} has dates without times. \code{POSIXct} has
%dates and times, including time zones. Comparisons (e.g. $>$),
%\code{seq()}, and \code{difftime()} are useful. \code{Date} also allows
%$+$ and $-$. \code{?DateTimeClasses} gives more information. See also package
%\code{chron}.
\code{Date}~只包含日期不包含时间.\code{POSIXct}~包括日期时间和时区信息.
相比而言(如.$>$),\code{seq()}~和\code{difftime()}~比较有用.\code{Date}~也可以使用$+$和$-$.
\code{?DateTimeClasses}可以给出更多的信息.详见\code{chron}包.
\everypar={\hangindent=9mm}
%\bcode{as.Date(s)} and \bcode{as.POSIXct(s)} convert to the respective
%class; \code{format(dt)} converts to a string representation. The
%default string format is '2001-02-21'. These accept a second argument
%to specify a format for conversion. Some common formats are:
\bcode{as.Date(s)}和\bcode{as.POSIXct(s)}转化各自的属性;\code{format(dt)}转化为
字符表达.默认的字符格式为'2006-07-24'.他们接受一个次要表达来指定转化的格式.一些常见的
格式为:
\describe{
\itemsep=0pt\parskip=0pt
%\item{\code{\%a}, \code{\%A}} {Abbreviated and full weekday name.}
\item{\code{\%a}, \code{\%A}} {精简和无精简'星期天'(weekday)名}
%\item{\code{\%b}, \code{\%B}} {Abbreviated and full month name.}
\item{\code{\%b}, \code{\%B}} {精简和无精简月名}
%\item{\code{\%d}} {Day of the month (01--31).}
\item{\code{\%d}} {月份中的日期 (01--31).}
%\item{\code{\%H}} {Hours (00--23).}
\item{\code{\%H}} {小时 (00--23).}
%\item{\code{\%I}} {Hours (01--12).}
\item{\code{\%I}} {小时 (01--12).}
%\item{\code{\%j}} {Day of year (001--366).}
\item{\code{\%j}} {年份中的日期 (001--366).}
%\item{\code{\%m}} {Month (01--12).}
\item{\code{\%m}} {月份 (01--12).}
%\item{\code{\%M}} {Minute (00--59).}
\item{\code{\%M}} {分钟 (00--59).}
%\item{\code{\%p}} {AM/PM indicator. }
\item{\code{\%p}} {AM/PM 指示.}
%\item{\code{\%S}} {Second as decimal number (00--61).}
\item{\code{\%S}} {十进制的秒 (00--61).}
%\item{\code{\%U}} {Week (00--53); the first Sunday as day 1 of week 1.}
\item{\code{\%U}} {星期 (00--53);第一个星期天作为第一个星期的第一天.}
%\item{\code{\%w}} {Weekday (0--6, Sunday is 0).}
\item{\code{\%w}} {星期天数 (0--6,周日为0).}
%\item{\code{\%W}} {Week (00--53); the first Monday as day 1 of week 1.}
\item{\code{\%W}} {周 (00--53);第一个周一作为第一个星期的第一天.}
%\item{\code{\%y}} {Year without century (00--99). Don't use.}
\item{\code{\%y}} {无世纪的年(00--99).不要使用.}
%\item{\code{\%Y}} {Year with century.}
\item{\code{\%Y}} {有世纪的年.}
%\item{\code{\%z}} {(output only.) Offset from Greenwich; \code{-0800} is 8 hours west of.}
\item{\code{\%z}} {(只输出.)格林威治补偿;\code{-0800}为格林威治西~8~小时.}
%\item{\code{\%Z}} {(output only.) Time zone as a character
%string (empty if not available).}
\item{\code{\%Z}} {(只输出.)时区作为字符串(无效为空).}
}
\bcode{weekdays(x)} 返回日期 \code{x}~的星期几
\bcode{months(x)} 返回日期 \code{x}~的月份
\bcode{quarters(x)} 返回日期 \code{x}~的季节 (Q1 - Q4)
%Where leading zeros are shown they will be used on output but are
%optional on input. See \code{?strftime}.
在输出时会碰到,显示数字前存在零的问题,但输入时可以选择性写零或无零.参见\code{?strftime}.
\section{图形装置(Graphics Devices)}
\everypar={\hangindent=9mm}
%\bcode{x11(), windows()} open a graphics window
\bcode{x11(), windows()} 打开一个绘图窗口
\bcode{dev.list()} 图形窗口列表
\bcode{dev.set()} 指定图形窗口
\bcode{plot.new()} 为绘制新图形结束当前图形窗口
%\bcode{savePlot{}} Saves the current plot on a windows device to a file.
\bcode{savePlot(file,type)} 将当前窗口中的绘图保存到文件 \code{file} ,保存文件类型\code{type} 可以选择
'wmf', 'mf', 'png', 'jpeg', 'jpg', 'bmp', 'ps', 'eps', 'pdf'