title: cannot install R tseries, quadprog ,xts packages in Linux
body: <p>I am using R version 3.4.0</p>
  
  <p>I'm trying to install tseries package on linux machine:</p>
  
  <pre><code>install.packages('https://cran.cnr.berkeley.edu/src/contrib/tseries_0.10-42.tar.gz',dependencies = TRUE,repos = NULL,type ="source")
  
  It gives error:
  ERROR: compilation failed for package 'xts'
  * removing '/usr/lib64/R/library/xts'
  ERROR: dependency 'xts' is not available for package 'TTR'
  * removing '/usr/lib64/R/library/TTR'
  ERROR: dependencies 'xts', 'TTR' are not available for package 'quantmod'
  * removing '/usr/lib64/R/library/quantmod'
  ERROR: dependencies 'quadprog', 'quantmod' are not available for package 'tseries'
  * removing '/usr/lib64/R/library/tseries'
  
  1: In install.packages("tseries", dependencies = TRUE) :
    installation of package 'quadprog' had non-zero exit status
  2: In install.packages("tseries", dependencies = TRUE) :
    installation of package 'xts' had non-zero exit status
  3: In install.packages("tseries", dependencies = TRUE) :
    installation of package 'TTR' had non-zero exit status
  4: In install.packages("tseries", dependencies = TRUE) :
    installation of package 'quantmod' had non-zero exit status
  5: In install.packages("tseries", dependencies = TRUE) :
    installation of package 'tseries' had non-zero exit status
  </code></pre>
  
  <p>Then I tried installing quadprog using:</p>
  
  <pre><code>install.packages('https://cran.cnr.berkeley.edu/src/contrib/quadprog_1.5-5.tar.gz',dependencies = TRUE,repos = NULL,type ="source")
  </code></pre>
  
  <p>It gives error :</p>
  
  <pre><code>/usr/bin/ld: cannot find -lgfortran
  collect2: error: ld returned 1 exit status
  make: *** [quadprog.so] Error 1
  ERROR: compilation failed for package 'quadprog'
  * removing '/usr/lib64/R/library/quadprog'
  </code></pre>
  
  <p>Please help what should i do. I'm facing hard time in installing these packages.</p>
  
  <p>I have installed R using :</p>
  
  <p>sudo yum -y install R-core R-devel</p>
  
  <p>I tried installing gfortran using :  <code>yum install gcc-gfortran</code></p>
  
  <p>It says :Package gcc-gfortran-4.4.7-18.el6.x86_64 already installed and latest version
  Nothing to do</p>