最近我似乎和合作者分享了很多代码。他们中的许多人是新手/中级R用户,并没有意识到他们必须安装他们还没有的包。
是否有一种优雅的方式来调用installed.packages(),比较那些我正在加载和安装如果丢失?
最近我似乎和合作者分享了很多代码。他们中的许多人是新手/中级R用户,并没有意识到他们必须安装他们还没有的包。
是否有一种优雅的方式来调用installed.packages(),比较那些我正在加载和安装如果丢失?
当前回答
我使用以下将检查包是否安装和依赖项是否更新,然后加载包。
p<-c('ggplot2','Rcpp')
install_package<-function(pack)
{if(!(pack %in% row.names(installed.packages())))
{
update.packages(ask=F)
install.packages(pack,dependencies=T)
}
require(pack,character.only=TRUE)
}
for(pack in p) {install_package(pack)}
completeFun <- function(data, desiredCols) {
completeVec <- complete.cases(data[, desiredCols])
return(data[completeVec, ])
}
其他回答
你可以使用require的返回值:
if(!require(somepackage)){
install.packages("somepackage")
library(somepackage)
}
我在安装后使用library,因为如果安装不成功或由于其他原因无法加载包,它将抛出异常。您可以使其更加健壮和可重用:
dynamic_require <- function(package){
if(eval(parse(text=paste("require(",package,")")))) return(TRUE)
install.packages(package)
return(eval(parse(text=paste("require(",package,")"))))
}
此方法的缺点是必须以引号传递包名,而对于真正的require则不这样做。
48 lapply_install_and_load <- function (package1, ...)
49 {
50 #
51 # convert arguments to vector
52 #
53 packages <- c(package1, ...)
54 #
55 # check if loaded and installed
56 #
57 loaded <- packages %in% (.packages())
58 names(loaded) <- packages
59 #
60 installed <- packages %in% rownames(installed.packages())
61 names(installed) <- packages
62 #
63 # start loop to determine if each package is installed
64 #
65 load_it <- function (p, loaded, installed)
66 {
67 if (loaded[p])
68 {
69 print(paste(p, "loaded"))
70 }
71 else
72 {
73 print(paste(p, "not loaded"))
74 if (installed[p])
75 {
76 print(paste(p, "installed"))
77 do.call("library", list(p))
78 }
79 else
80 {
81 print(paste(p, "not installed"))
82 install.packages(p)
83 do.call("library", list(p))
84 }
85 }
86 }
87 #
88 lapply(packages, load_it, loaded, installed)
89 }
我想贡献一下我用的:
testin <- function(package){if (!package %in% installed.packages())
install.packages(package)}
testin("packagename")
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);
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" ) )