title: R Variance Inflation Factors - Warning : No function found corresponding to methods exports from ‘SparseM’ for: ‘coerce’
body: <p>I am playing around with the car library for R and have encountered the following warning after calling the variance_inflation_factors function on my data model.</p>
  
  <blockquote>
    <p>No function found corresponding to methods exports from ‘SparseM’ for:
    ‘coerce’</p>
  </blockquote>
  
  <p>This error is the result of the following code </p>
  
  
  
  <pre class="lang-r prettyprint-override"><code>library(car)
  
  data = read.table("path/to/data.txt")
  attach(data)
  
  model = lm(Y ~ X1 + X2 + X3)
  
  vif(model)
  </code></pre>
  
  <p>But still yields a regular output shown as</p>
  
  
  
  <pre class="lang-sh prettyprint-override"><code>      X1       X2       X3
  1.578524 2.276641 2.021541
  </code></pre>
  
  <p>All together the output appears as </p>
  
  
  
  <pre class="lang-sh prettyprint-override"><code>Warning message:
  no function found corresponding to methods exports from ‘SparseM’ for: ‘coerce’
        X1       X2       X3
  1.578524 2.276641 2.021541
  </code></pre>
  
  <p>Is my output affected by the lack of the coerce method? </p>