title: how to control wordcloud picture size
body: <p>I just want to save a simple wordcloud in a file 200x150px but am getting 640x480 pixel instead. What am I doing wrong?</p>
  
  <pre><code>from matplotlib import pyplot as plt
  from wordcloud import WordCloud
  cloud = WordCloud(width=200,height=150)
  plt.imshow(cloud.generate_from_frequencies(t))
  plt.savefig('c.png')
  plt.clf()
  </code></pre>