Elegant way to check for missing packages and inst

Question

I seem to be sharing a lot of code with coauthors these days. Many of them are novice/intermediate R users and don't realize that they have to install packages they don't already have.

Is there an elegant way to call installed.packages(), compare that to the ones I am loading and install if missing?

Answer 1

Sure.

You need to compare 'installed packages' with 'desired packages'. That's very close to what I do with CRANberries as I need to compare 'stored known packages' with 'currently known packages' to determine new and/or updated packages.

So do something like

AP <- available.packages(contrib.url(repos[i,"url"]))   # available t repos[i]

to get all known packages, simular call for currently installed packages and compare that to a given set of target packages.

Answer 2

Quite basic one.

pkgs = c("pacman","data.table")
if(length(new.pkgs <- setdiff(pkgs, rownames(installed.packages())))) install.packages(new.pkgs)

Answer 3

library <- function(x){
  x = toString(substitute(x))
if(!require(x,character.only=TRUE)){
  install.packages(x)
  base::library(x,character.only=TRUE)
}}

This works with unquoted package names and is fairly elegant (cf. GeoObserver's answer)

Answer 4

source("https://bioconductor.org/biocLite.R")
if (!require("ggsci")) biocLite("ggsci")

Answer 5

if (!require('ggplot2')) install.packages('ggplot2'); library('ggplot2')

"ggplot2" is the package. It checks to see if the package is installed, if it is not it installs it. It then loads the package regardless of which branch it took.

Answer 6

I have implemented the function to install and load required R packages silently. Hope might help. Here is the code:

# 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);