下面这个简单的函数非常好用:

  usePackage<-function(p){
      # load a package if installed, else load after installation.
      # Args:
      #   p: package name in quotes

      if (!is.element(p, installed.packages()[,1])){
        print(paste('Package:',p,'Not found, Installing Now...'))
        install.packages(p, dep = TRUE)}
      print(paste('Loading Package :',p))
      require(p, character.only = TRUE)  
    }

(不是我的，一段时间前在网上找到了这个，从那时起就一直在使用它。不确定原始来源)

此解决方案将获取包名的字符向量并尝试加载它们，或者在加载失败时安装它们。它依赖于require的返回行为来做到这一点，因为…

Require返回(不可见的)一个逻辑，指示所需的包是否可用

因此，我们可以简单地查看是否能够加载所需的包，如果不能，则使用依赖项安装它。所以给定一个你想要加载的包的字符向量…

foo <- function(x){
  for( i in x ){
    #  require returns TRUE invisibly if it was able to load package
    if( ! require( i , character.only = TRUE ) ){
      #  If package was not able to be loaded then re-install
      install.packages( i , dependencies = TRUE )
      #  Load package after installing
      require( i , character.only = TRUE )
    }
  }
}

#  Then try/install packages...
foo( c("ggplot2" , "reshape2" , "data.table" ) )

达森·k和我有一个吃豆人包可以很好地做到这一点。包中的p_load函数执行此操作。第一行代码只是为了确保安装了pacman。

if (!require("pacman")) install.packages("pacman")
pacman::p_load(package1, package2, package_n)

在我的例子中，我想要一个可以从命令行(实际上是通过Makefile)运行的一行程序。下面是一个安装“VGAM”和“feather”的例子，如果它们还没有安装:

R -e 'for (p in c("VGAM", "feather")) if (!require(p, character.only=TRUE)) install.packages(p, repos="http://cran.us.r-project.org")'

在R内部，它就是:

for (p in c("VGAM", "feather")) if (!require(p, character.only=TRUE)) install.packages(p, repos="http://cran.us.r-project.org")

除了前面的解之外，这里没有别的解:

我只说一句 我硬编码回购参数(以避免任何弹出窗口询问使用的镜像) 我不想费心定义一个在其他地方使用的函数

还要注意重要的字符。only=TRUE(如果没有它，require将尝试加载包p)。

今天，我偶然发现了rlang包提供的两个方便函数，即is_installed()和check_installed()。

从帮助页面(强调添加):

These functions check that packages are installed with minimal side effects. If installed, the packages will be loaded but not attached. is_installed() doesn't interact with the user. It simply returns TRUE or FALSE depending on whether the packages are installed. In interactive sessions, check_installed() asks the user whether to install missing packages. If the user accepts, the packages are installed [...]. If the session is non interactive or if the user chooses not to install the packages, the current evaluation is aborted.

interactive()
#> [1] FALSE
rlang::is_installed(c("dplyr"))
#> [1] TRUE
rlang::is_installed(c("foobarbaz"))
#> [1] FALSE
rlang::check_installed(c("dplyr"))
rlang::check_installed(c("foobarbaz"))
#> Error:
#> ! The package `foobarbaz` is required.

由reprex包在2022-03-25创建(v2.0.1)

我已经实现了无声安装和加载所需R包的功能。希望也许会有所帮助。代码如下:

# Function to Install and Load R Packages
Install_And_Load <- function(Required_Packages)
{
    Remaining_Packages <- Required_Packages[!(Required_Packages %in% installed.packages()[,"Package"])];

    if(length(Remaining_Packages)) 
    {
        install.packages(Remaining_Packages);
    }
    for(package_name in Required_Packages)
    {
        library(package_name,character.only=TRUE,quietly=TRUE);
    }
}

# Specify the list of required packages to be installed and load    
Required_Packages=c("ggplot2", "Rcpp");

# Call the Function
Install_And_Load(Required_Packages);