sink(file = 'R.log', split=T)

options(scipen=5)

.ls.objects <- function (pos = 1, pattern, order.by = "Size", decreasing=TRUE, head =     TRUE, n = 10) {
  # based on postings by Petr Pikal and David Hinds to the r-help list in 2004
  # modified by: Dirk Eddelbuettel (http://stackoverflow.com/questions/1358003/tricks-to-    manage-the-available-memory-in-an-r-session) 
  # I then gave it a few tweaks (show size as megabytes and use defaults that I like)
  # a data frame of the objects and their associated storage needs.
  napply <- function(names, fn) sapply(names, function(x)
          fn(get(x, pos = pos)))
  names <- ls(pos = pos, pattern = pattern)
  obj.class <- napply(names, function(x) as.character(class(x))[1])
  obj.mode <- napply(names, mode)
  obj.type <- ifelse(is.na(obj.class), obj.mode, obj.class)
  obj.size <- napply(names, object.size) / 10^6 # megabytes
  obj.dim <- t(napply(names, function(x)
            as.numeric(dim(x))[1:2]))
  vec <- is.na(obj.dim)[, 1] & (obj.type != "function")
  obj.dim[vec, 1] <- napply(names, length)[vec]
  out <- data.frame(obj.type, obj.size, obj.dim)
  names(out) <- c("Type", "Size", "Rows", "Columns")
  out <- out[order(out[[order.by]], decreasing=decreasing), ]
  if (head)
    out <- head(out, n)
  out
}

我有一个环境变量R_USER_WORKSPACE，它指向包的顶部目录。在. rprofile中，我定义了一个函数devlib，它设置了工作目录(以便data()工作)，并在R子目录中获取所有.R文件。它与上面Hadley的l()函数非常相似。

devlib <- function(pkg) {
  setwd(file.path(Sys.getenv("R_USER_WORKSPACE", "."), deparse(substitute(pkg)), "dev"))
  sapply(list.files("R", pattern=".r$", ignore.case=TRUE, full.names=TRUE), source)
  invisible(NULL)
}

.First <- function() {
  setwd(Sys.getenv("R_USER_WORKSPACE", "."))
  options("repos" = c(CRAN = "http://mirrors.softliste.de/cran/", CRANextra="http://www.stats.ox.ac.uk/pub/RWin"))
}

.Last <- function() update.packages(ask="graphics")

options(stringsAsFactors=FALSE)

虽然我的. r配置文件中没有这个，因为它可能会破坏我的合作者的代码，但我希望它是默认的。为什么?

1)字符向量使用更少的内存(但只是很少);

2)更重要的是，我们可以避免这样的问题:

> x <- factor(c("a","b","c"))
> x
[1] a b c
Levels: a b c
> x <- c(x, "d")
> x
[1] "1" "2" "3" "d"

and

> x <- factor(c("a","b","c"))
> x[1:2] <- c("c", "d")
Warning message:
In `[<-.factor`(`*tmp*`, 1:2, value = c("c", "d")) :
  invalid factor level, NAs generated

因子在你需要的时候很有用(比如在图中实现排序)，但大多数时候都很麻烦。

让data.frames的显示有点像'head'，只是不需要输入'head'

print.data.frame <- function(df) {
   if (nrow(df) > 10) {
      base::print.data.frame(head(df, 5))
      cat("----\n")
      base::print.data.frame(tail(df, 5))
   } else {
      base::print.data.frame(df)
   }
}

(从如何使'头'自动应用到输出?)

我经常需要调用一系列调试调用，取消注释它们可能非常乏味。在SO社区的帮助下，我找到了以下解决方案，并将其插入到我的. rprofile .site中。# BROWSER是为我的Eclipse任务设置的，这样我就可以在任务视图窗口中对浏览器调用有一个概述。

# turn debugging on or off
# place "browser(expr = isTRUE(getOption("debug"))) # BROWSER" in your function
# and turn debugging on or off by bugon() or bugoff()
bugon <- function() options("debug" = TRUE)
bugoff <- function() options("debug" = FALSE) #pun intended

我喜欢保存我的R命令历史，并在每次运行R命令时都可用:

在shell或.bashrc中:

export R_HISTFILE=~/.Rhistory

在.Rprofile:

.Last <- function() {
        if (!any(commandArgs()=='--no-readline') && interactive()){
                require(utils)
                try(savehistory(Sys.getenv("R_HISTFILE")))
        }
}