How to use the spread function properly in tidyr
<p>How do I change the following table from:</p>

<pre><code>Type    Name    Answer     n
TypeA   Apple   Yes        5
TypeA   Apple   No        10
TypeA   Apple   DK         8
TypeA   Apple   NA        20
TypeA   Orange  Yes        6
TypeA   Orange  No        11
TypeA   Orange  DK         8
TypeA   Orange  NA        23
</code></pre>

<p>Change to:</p>

<pre><code>Type    Name    Yes   No   DK   NA  
TypeA   Apple   5     10   8    20
TypeA   Orange  6     11   8    23
</code></pre>

<p>I used the following codes to get the first table.</p>

<pre><code>df_1 &lt;- 
  df %&gt;% 
  group_by(Type, Name, Answer) %&gt;% 
  tally()  
</code></pre>

<p>Then I tried to use the spread command to get to the 2nd table, but I got the following error message:</p>

<blockquote>
  <p>"Error: All columns must be named"</p>
</blockquote>

<pre><code>df_2 &lt;- spread(df_1, Answer)
</code></pre>