Q:

R language package ltm issue with library command

I am hoping the someone can answer a short question on ltm.
ltm installs successfully with 
 install.packages("ltm")

but the library command:
 library(ltm)

throws this error:

library(ltm)
  Error: package ‘polycor’ required by ‘ltm’ could not be found

I cannot locate polycor in the install.packages menu in RStudio.
This documentation on ltm: https://cran.r-project.org/web/packages/ltm/ltm.pdf does not mention polycor
I have used this package before without a problem, but it has been about one year since I last used it.
Thanks

A:

You may need to update R. From CRAN polycor info it says the package depends on R>3.3.0.  Additionally, this site may help.
If you are using linux, you should be able to type: R --version into a terminal to confirm which version you have
edit: though it appears my R version is 3.2.3...I may need to change my ubuntu repo
 sudo apt-cache showpkg r-base
 sudo apt-get upgrade r-base
 sudo apt-get install r-base

