title: r VennDiagram make.truth.table 'error could not find function' how can I get this to work?
body: <p>I am trying out the example from the package documentation; 
  <code>VennDiagram::make.truth.table:</code></p>
  
  <pre><code> make.truth.table(c(a = 1, b = 2, c = 3, d = 4))
  </code></pre>
  
  <p>I get this error:</p>
  
  <pre><code>Error in make.truth.table(c(a = 1, b = 2, c = 3, d = 4)) : 
    could not find function "make.truth.table"
  </code></pre>
  
  <p>I have found nothing online about this function except the <code>VennDiagram</code> documentation.</p>
  
  <p>Please help me understand:</p>
  
  <p>a) the function output</p>
  
  <p>b) why it is not working</p>
  
  <p>I am using:</p>
  
  <pre><code>R version 3.4.1 (2017-06-30)
  Platform: x86_64-w64-mingw32/x64 (64-bit)
  Running under: Windows 7 x64 (build 7601) Service Pack 1
  RStudio version 1.0.153
  </code></pre>
  
  <p>attached base packages:</p>
  
  <pre><code>[1] grid      stats     graphics  grDevices utils     datasets  methods   base  
  </code></pre>
  
  <p>other attached packages:</p>
  
  <pre><code>[1] VennDiagram_1.6.17  futile.logger_1.4.3 knitr_1.17
  </code></pre>