r - 查看 R 包的源代码

Question

是否有一种简单的方法可以从交互式环境中查看 R 包（或包中的方法）的源代码？

Answer 1

只需输入不带括号的函数/方法的名称：

R> base::rev.default 
function (x) 
if (length(x)) x[length(x):1L] else x
<environment: namespace:base>

另请参阅R-Help Desk - Accessing the Sources in R News 第 6/4 卷，2006 年 10 月。

Answer 2

How you find the source code depends on the type of function. See my answer to this related question.

As rcs pointed out, if you want to specify a package, you can use ::.

> lattice::xyplot
function (x, data, ...) 
UseMethod("xyplot")
<environment: namespace:lattice>

Not all functions from a package will be exported (i.e. made publically available); for these you need to use :::.

> lattice::xyplot.formula
Error: 'xyplot.formula' is not an exported object from 'namespace:lattice'

> lattice:::xyplot.formula
function (x, data = NULL, allow.multiple = is.null(groups) || 
    outer, outer = !is.null(groups), auto.key = FALSE, aspect = "fill", 
    panel = lattice.getOption("panel.xyplot"), prepanel = NULL, 
    scales = list(), strip = TRUE, groups = NULL, xlab, xlim, 
    ylab, ylim, drop.unused.levels = lattice.getOption("drop.unused.levels"), 
    ..., lattice.options = NULL, default.scales = list(), subscripts = !is.null(groups), 
    subset = TRUE) 
{
    formula <- x
    dots <- list(...)
# etc.

Answer 3

要找出您想要查看的方法，请编写methods(funcOfInterest)

有时它是不够的print(funcOfInterest.class)。那就试试print(getAnywhere(funcOfInterest.class))吧。

Answer 4

从https://cloud.r-project.org/src/contrib下载包源并使用您喜欢的编辑器打开它。找到函数定义（您可以使用grep它）。有时您也可以找到有用的介绍。