title: Grouped bar chart turns into stacked bar chart ggplot
body: <p>I have an issue where a grouped bar chart made with ggplot unintentionally transforms into a stacked bar chart after minor changes in my dataset. I have the following initial dataset and bar chart:</p>
  
  <pre><code>&gt; DataT
      Treatment Round N  Initial        sd        se        ci
   1         EE     1 3 3000.000    0.0000   0.00000    0.0000
   2         EE     2 3 2524.444  463.8167 267.78469 1152.1845  
   3         EE     3 3 1621.481 1297.3331 749.01563 3222.7542
   4         EE     4 1 2720.000        NA        NA       NaN
   5         EU     1 3 3000.000    0.0000   0.00000    0.0000
   6         EU     2 3 2922.222  134.7151  77.77778  334.6508
   7         EU     3 3 2582.963  514.6560 297.13677 1278.4763
   8         EU     4 3 2163.951  547.9230 316.34352 1361.1163
   9         UE     1 3 3000.000    0.0000   0.00000    0.0000
   10        UE     2 3 2280.000  624.4286 360.51404 1551.1667
   11        UE     3 3 1244.444 1520.4596 877.83779 3777.0311
   12        UE     4 1 2686.667        NA        NA       NaN
   13        UU     1 3 3000.000    0.0000   0.00000    0.0000
   14        UU     2 3 2626.667  283.7840 163.84274  704.9584
   15        UU     3 3 1835.556  474.8957 274.18116 1179.7063
   16        UU     4 3 1287.407 1022.8653 590.55158 2540.9384
   &gt; p &lt;-ggplot(DataT, aes(x=Treatment, y=Initial))
   &gt; p +geom_bar(position = position_dodge(),stat = "identity", aes(fill = 
   Round))
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/6wRUE.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/6wRUE.png" alt="First Bar Chart"></a></p>
  
  <p>However, this dataset had a few errors. After changing the dataset to the following, my bar chart style changed from a grouped to a stacked chart. </p>
  
  <pre><code>&gt; DataNew
     Treatment Round N   Initial        sd        se        ci
  1         EE     1 3 3000.0000    0.0000   0.00000    0.0000
  2         EE     2 3 2524.4444  463.8167 267.78469 1152.1845
  3         EE     3 3 1621.4815 1297.3331 749.01563 3222.7542
  4         EE     4 3  906.6667 1570.3927 906.66667 3901.0718
  5         EU     1 3 3000.0000    0.0000   0.00000    0.0000
  6         EU     2 3 2922.2222  134.7151  77.77778  334.6508
  7         EU     3 3 2582.9630  514.6560 297.13677 1278.4763
  8         EU     4 3 2163.9506  547.9230 316.34352 1361.1163
  9         UE     1 3 3000.0000    0.0000   0.00000    0.0000
  10        UE     2 3 2280.0000  624.4286 360.51404 1551.1667
  11        UE     3 3 1244.4444 1520.4596 877.83779 3777.0311
  12        UE     4 3  895.5556 1551.1477 895.55556 3853.2646
  13        UU     1 3 3000.0000    0.0000   0.00000    0.0000
  14        UU     2 3 2626.6667  283.7840 163.84274  704.9584
  15        UU     3 3 1835.5556  474.8957 274.18116 1179.7063
  16        UU     4 3 1287.4074 1022.8653 590.55158 2540.9384
  &gt; p &lt;-ggplot(DataNew, aes(x=Treatment, y=Initial))
  &gt; p +geom_bar(position = position_dodge(),stat = "identity", aes(fill = 
  Round))
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/KMyjK.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/KMyjK.png" alt="Second Bar Chart"></a></p>
  
  <p>How do I keep the second chart as a grouped bar chart?
  My thanks in advance!</p>