[R] Installing Packages

[Duncan Murdoch]

On 11/03/2020 7:46 a.m., Jeff Reichman wrote:
> R-Help
> 
>   
> 
> Recently I've started receiving the following message when updating packages
> - "Do you want to install from sources the packages which need compilation."
> I generally click "Yes," but what is this asking me. That is it appears to
> be re-compiling certain packages? Why?
> 

As the others answered:  that's because compiled versions aren't 
available on the server yet.

What they didn't say is why you might want to say "no".  You would say 
that if you expect the compile on your own system to fail, perhaps 
because you don't have compilers or special libraries installed.  R can 
install packages whose source is all in R, but needs external tools to 
install packages that incorporate other languages like C, C++ and 
Fortran.  Even if you have those compilers, some packages will need to 
link to libraries outside of R.

If you say "no", then R will look for an older compiled version of the 
package and install that.  This might cause trouble if some other 
package depends on the latest version of its dependencies:  you won't be 
able to install the latest version of that package either.

I'd recommend trying with "yes", then trying again with "no" if there 
were any install failures.

Duncan Murdoch