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词汇表
想要玩得转R，重要的一点是有一个好的工作词汇表。以下是我认为的一个好的词汇表。你不必熟悉每个函数的细节，但是你应该知道它们的存在。如果词汇表中的函数你没有听说过，我强烈建议你阅读下相关文档。
我阅读了base包、stats包、untils包所有的函数，并提取了我认为最重要的函数，组成了下列的词汇表。列表中也有一些其他包中的重要函数，而且还有一些更加重要的，比如options()。
基本函数
# The first functions to learn ? str # Important operators and assignment %in%, match =, <-, <<- $, [, [[, head, tail, subset with assign, get # Comparison all.equal, identical !=, ==, >, >=, <, <= is.na, complete.cases is.finite # Basic math *, +, -, /, ^, %%, %/% abs, sign acos, asin, atan, atan2 sin, cos, tan ceiling, floor, round, trunc, signif exp, log, log10, log2, sqrt max, min, prod, sum cummax, cummin, cumprod, cumsum, diff pmax, pmin range mean, median, cor, sd, var rle # Functions to do with functions function missing on.exit return, invisible # Logical & sets &, |, !, xor all, any intersect, union, setdiff, setequal which # Vectors and matrices c, matrix # automatic coercion rules character > numeric > logical length, dim, ncol, nrow cbind, rbind names, colnames, rownames t diag sweep as.matrix, data.matrix # Making vectors c rep, rep_len seq, seq_len, seq_along rev sample choose, factorial, combn (is/as).(character/numeric/logical/...) # Lists & data.frames list, unlist data.frame, as.data.frame split expand.grid # Control flow if, &&, || (short circuiting) for, while next, break switch ifelse # Apply & friends lapply, sapply, vapply apply tapply replicate
常见数据结构相关函数
# Date time ISOdate, ISOdatetime, strftime, strptime, date difftime julian, months, quarters, weekdays library(lubridate) # Character manipulation grep, agrep gsub strsplit chartr nchar tolower, toupper substr paste library(stringr) # Factors factor, levels, nlevels reorder, relevel cut, findInterval interaction options(stringsAsFactors = FALSE) # Array manipulation array dim dimnames aperm library(abind)
统计函数
# Ordering and tabulating duplicated, unique merge order, rank, quantile sort table, ftable # Linear models fitted, predict, resid, rstandard lm, glm hat, influence.measures logLik, df, deviance formula, ~, I anova, coef, confint, vcov contrasts # Miscellaneous tests apropos("\.test$") # Random variables (q, p, d, r) * (beta, binom, cauchy, chisq, exp, f, gamma, geom, hyper, lnorm, logis, multinom, nbinom, norm, pois, signrank, t, unif, weibull, wilcox, birthday, tukey) # Matrix algebra crossprod, tcrossprod eigen, qr, svd %*%, %o%, outer rcond solve
使用R
# Workspace ls, exists, rm getwd, setwd q source install.packages, library, require # Help help, ? help.search apropos RSiteSearch citation demo example vignette # Debugging traceback browser recover options(error = ) stop, warning, message tryCatch, try
输入/输出
# Output
print, cat
message, warning
dput
format
sink, capture.output
# Reading and writing data
data
count.fields
read.csv, write.csv
read.delim, write.delim
read.fwf
readLines, writeLines
readRDS, saveRDS
load, save
library(foreign)
# Files and directories
dir
basename, dirname, tools::file_ext
file.path
path.expand, normalizePath
file.choose
file.copy, file.create, file.remove, file.rename, dir.create
file.exists, file.info
tempdir, tempfile
download.file, library(downloader)