Installing R in ubuntu

Question

I am trying to install R in ubuntu, but faced the following error:

Reading package lists... Done
Building dependency tree       
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 r-base : Depends: r-base-core (>= 3.0.0-2lucid) but it is not going to be installed
          Depends: r-recommended (= 3.0.0-2lucid) but it is not going to be installed
          Recommends: r-base-html but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

Before doing this, I also added this line to /etc/apt/sources.list

# added from cran.cnr.berkley.edu for R
deb http://cran.cnr.berkeley.edu/bin/linux/ubuntu lucid/

But when I tried to update, I received an authentication error:

...
Reading package lists... Done
W: GPG error: http://cran.cnr.berkeley.edu lucid/ Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 51716619E084DAB9

Any idea how to solve this issue?

Answer 1

I also did the instructions for SECURE APT, but still I get the following dependency error:

The following packages have unmet dependencies: r-base-dev : Depends: r-base-core (>= 3.0.1-3lucid) but it is not going to be installed E: Unable to correct problems, you have held broken packages.

But then I used a different mirror (by changing /etc/apt/sources.list) it worked:

deb http://cran.mtu.edu/bin/linux/ubuntu precise/