Dear folks,

I am wondering how to stop my further script if required packages are not loaded properly? Somehow packages are installed but while loading its failed and gives error. However, my script run further but its fail when he found function of that unloaded package. I felt, because of dependencies of that packages not installed properly.

My function to install pkgs:

# load multiple packages by once but first to check if installed?
pkgs= c("A", "B","C","D")

# Install packages if not already installed
inst_bio <- pkgs %in% installed.packages()

if(length(pkgs[!inst_bio]) > 0)
{
 source("http://bioconductor.org/biocLite.R") ## online use
 suppressWarnings(suppressMessages(lapply(pkgs[!inst_bio], biocLite, dependencies = T,suppressUpdates=T,ask=F,suppressAutoUpdate=T)))
}

## Load packages into session
suppressWarnings(suppressMessages(lapply(pkgs, require, character.only=T)))

Error : object ålatticeGrobå is not exported by 'namespace:gridExtra'
[[1]]
[1] TRUE

[[2]]
[1] TRUE

[[3]]
[1] FALSE

[[4]]
[1] TRUE

Then I tried manually to install latticeGrob

Warning message:

package ålatticeGrobå is not available (for R version 3.1.3)

So, my question is, how to stop running script if packages are not loaded properly into session?

Thank you