Check if R package is installed then load library

Question

Our R scripts are used on multiple users on multiple computers and hence there are deviations in which packages are installed on each computer. To ensure that each script wo

Answer 1

I wrote this function the other day that I thought would be useful...

install_load <- function (package1, ...)  {   

   # convert arguments to vector
   packages <- c(package1, ...)

   # start loop to determine if each package is installed
   for(package in packages){

       # if package is installed locally, load
       if(package %in% rownames(installed.packages()))
          do.call('library', list(package))

       # if package is not installed locally, download, then load
       else {
          install.packages(package)
          do.call("library", list(package))
       }
   } 
}

Answer 2

Though @maloneypatr function works fine, but it is quite silent and does not respond on success of packages loaded. I built below function that does make some checks on user entry and also respond on the number of packages being successfully installed.

lubripack <- function(...,silent=FALSE){

  #check names and run 'require' function over if the given package is installed
  requirePkg<- function(pkg){if(length(setdiff(pkg,rownames(installed.packages())))==0)
                                    require(pkg, quietly = TRUE,character.only = TRUE)
                            }

  packages <- as.vector(unlist(list(...)))
  if(!is.character(packages))stop("No numeric allowed! Input must contain package names to install and load")

  if (length(setdiff(packages,rownames(installed.packages()))) > 0 )
     install.packages(setdiff(packages,rownames(installed.packages())),
                      repos = c("https://cran.revolutionanalytics.com/", "http://owi.usgs.gov/R/"))

  res<- unlist(sapply(packages, requirePkg))

  if(silent == FALSE && !is.null(res)) {cat("\nBellow Packages Successfully Installed:\n\n")
                    print(res)
                   }
}

Note 1:

If silent = TRUE(all capital silent), it installs and loads packages without reporting. If silent = FALSE, it reports successful installation of packages. Default value is silent = FALSE

How to use

lubripack(“pkg1","pkg2",.,.,.,.,"pkg")

Example 1: When all packages are valid and mode is not silent

lubripack(“shiny","ggvis")

or

lubripack(“shiny","ggvis", silent = FALSE)

Output

Example 2: When all packages are valid and mode is silent

lubripack(“caret","ggvis","tm", silent = TRUE) 

Output 2

Example 3: When package cannot be found

lubripack(“shiny","ggvis","invalidpkg", silent=FALSE) 

Output 3

---

How to Install Package:

Run below code to download the package and install it from GitHub. No need to have GitHub Account.

library(devtools)
install_github("espanta/lubripack")

Answer 3

The following can be used:

check.and.install.Package<-function(package_name){
    if(!package_name%in%installed.packages()){
        install.packages(package_name)
    }
}

check.and.install.Package("RTextTools")
check.and.install.Package("e1071")

Answer 4

The CRAN pacman package that I maintain can address this nicely. Using the following header (to ensure pacman is installed first) and then the p_load function will try to load the package and then get them from CRAN if R can't load the package.

if (!require("pacman")) install.packages("pacman"); library(pacman)
p_load(qdap, ggplot2, fakePackage, dplyr, tidyr)

Answer 5

Have a look at this nice function: klick

Answer 6

Use library(x,character.only=TRUE). Also you don't need the last line as suppressPackageStartupMessages(library(x,character.only=TRUE)) already loads the package.

EDIT: @LarsKotthoff is right, you already load the package inside of the if brackets. There you already use option character.only=TRUE so everything is good if you just remove last to lines of your function body.