title: Use ggplot2 to generate histogram from each row of data properly
body: <p>I have a set of data like below:</p>
  
  <pre><code>pos A   C   G   T
  0   0.291398    0.190061    0.315722    0.202818
  1   0.315597    0.227511    0.175448    0.281445
  2   0.252149    0.194597    0.222815    0.330438
  </code></pre>
  
  <p>Then I imported the table:</p>
  
  <pre><code>library(ggplot2)
  d = read.table(tablename, sep = '\t', header = T)
  d = d[2:5]
  data.frame(t(d))
  </code></pre>
  
  <p>And I got a reformatted table as below:</p>
  
  <pre><code>        X1       X2       X3
  A 0.291398 0.315597 0.252149
  C 0.190061 0.227511 0.194597
  G 0.315722 0.175448 0.222815
  T 0.202818 0.281445 0.330438
  </code></pre>
  
  <p>However, when I tried to plot it:</p>
  
  <pre><code>qplot(X1, data = d, geom = 'histogram')
  </code></pre>
  
  <p>It gives the image below:</p>
  
  <p><img src="https://i.stack.imgur.com/MoNkL.png" alt="enter image description here"></p>
  
  <p>And what I want should be like:(I used libreoffice, so the color and the width and other parameters do not matter)
  <img src="https://i.stack.imgur.com/cIPJP.png" alt="enter image description here"> </p>
  
  <p>May I know how to correct my code to make this shape?
  Any help is appreciated. Sorry but I am really new to R and ggplot2.</p>