title: R - Error in arules and arulesViz packages
body: <p>I am using the <code>arules</code> and <code>arulesViz</code> package in R to implement a set of association rules on my data. It worked fine till few days back. But now I am getting the below error whenever I load the R file where I used this package.</p>
  
  <pre><code>Loading required package: arules
  Loading required package: Matrix
  Attaching package: ‘arules’
  The following objects are masked from ‘package:base’:
  %in%, write
  Error in length(obj) : Method length not implemented for class rules 
  In addition: Warning message:
  package ‘arules’ was built under R version 3.1.3 
  Error in length(obj) : Method length not implemented for class rules 
  Error in length(obj) : Method length not implemented for class rules 
  Error in length(obj) : Method length not implemented for class rules
  </code></pre>
  
  <p>If I use the <code>plot()</code> function from <code>arulesViz</code> I face this below error:</p>
  
  <pre><code>Error in seq_along(x) : Method length not implemented for class rules
  </code></pre>
  
  <p>So tried to uninstall the package and reinstalled it. It worked only for the first time after reinstallation, it also threw the below error when I used for the first time after reinstallation.</p>
  
  <pre><code>Loading required package: arules
  Loading required package: Matrix
  
  Attaching package: ‘arules’
  The following objects are masked from ‘package:base’:
  %in%, write
  </code></pre>
  
  <p>But once I saved the file and loaded it back the old error messages repeated again.  I searched in Google but nothing close to this type of error is ever posted by anyone. Your help is appreciated. Thanks.</p>