title: Sort a tibble by index in R
body: <p>Looking to sort a tibble by index in R. Any way to do this without using a reverse sequence?</p>
  
  <pre><code>library(tibble)
  library(dplyr)
  
      options(tibble.width = Inf)
      options(dplyr.print_max = Inf) 
  </code></pre>
  
  <p>Returns the tail for comparison...</p>
  
  <pre><code>iris %&gt;% tail
  # Sepal.Length Sepal.Width Petal.Length Petal.Width   Species
  # 145          6.7         3.3          5.7         2.5 virginica
  # 146          6.7         3.0          5.2         2.3 virginica
  # 147          6.3         2.5          5.0         1.9 virginica
  # 148          6.5         3.0          5.2         2.0 virginica
  # 149          6.2         3.4          5.4         2.3 virginica
  # 150          5.9         3.0          5.1         1.8 virginica
  
  (tibbleIris &lt;- as_tibble(iris))
  </code></pre>
  
  <p>Can sort by reverse sequence, but it's not by index...</p>
  
  <pre><code>tibbleIris[nrow(tibbleIris):1,] # Sorts in reverse order
  # # A tibble: 150 × 5
  # Sepal.Length Sepal.Width Petal.Length Petal.Width    Species
  # &lt;dbl&gt;       &lt;dbl&gt;        &lt;dbl&gt;       &lt;dbl&gt;     &lt;fctr&gt;
  #   1            5.9         3.0          5.1         1.8  virginica
  # 2            6.2         3.4          5.4         2.3  virginica
  # 3            6.5         3.0          5.2         2.0  virginica
  # 4            6.3         2.5          5.0         1.9  virginica
  # 5            6.7         3.0          5.2         2.3  virginica
  # 6            6.7         3.3          5.7         2.5  virginica
  
  
  tibbleIris %&gt;% arrange(-index)
  # Error: object 'index' not found
  </code></pre>