title: build histograms of the distribution of all numerical variables
body: <p>I need to build histograms of the distribution of all numerical variables and i really dont catch how to properly do this</p>
  <pre><code>import pandas as pd
  ind = [5375, 11681, 5325, 679, 12625, 8090, 11518, 16341, 2607,1742]
  dats = {
  'index' : [5376, 11682, 5326, 680, 12626, 8091, 11519, 16342, 2608,1743],
  'date': [2011-8-16, 2012-5-6,2011-8-14,2011-1-31,2012-6-15,2011-12-8, 2011-4-30,2012-11-18, 2011-4-23,2011-3-18],
  'season': [4,3,4,2,3,1,3,1,3,2],
  'yr': [0,1,0,0,1,0,1,1,0,0],
  'mnth': [8,5,8,1,6,12,4,11,4,3],
  'hr': [21,22,19,15,6,18,3,15,13,7],
  'holiday': [0,0,0,0,0,0,0,0,0,0],
  'weekday': [2,0,0,1,5,4,1,0,6,5],
  'workingday': [1,0,0,1,1,1,1,0,0,1],
  'weathersit': [1,1,1,2,1,1,1,1,1,1],
  'temp':[0.72,0.56,0.72,0.16,0.54,0.28,0.40,0.42,0.52,0.4],
  'atemp': [0.6667, 0.5303, 0.6970, 0.1818, 0.5152, 0.2727, 0.4091, 0.4242, 0.5000, 0.4091],
  'hum':[0.54, 0.73, 0.74, 0.59, 0.83, 0.52, 0.76, 0.54, 0.83, 0.66],
  'windspeed': [0.0000, 0.1642, 0.2239, 0.1343, 0.1343, 0.2239, 0.1642, 0.2836, 0.3881, 0.1940],
  'cnt': [215, 157, 259, 44, 151, 318, 4, 407, 312, 123]
  }
  data = pd.DataFrame(data=dats, index=ind)
  </code></pre>
  <p>As i understand, numerical variables are each of these columns</p>
  <pre><code>data_numerical = data
  fig, ax = plt.subplots(2, 2, figsize=(20, 10)) #necessary line
  plt.bar(data=data_numerical, x=variable, ax=subplot)
  </code></pre>
  <p>So what do i need to fix here?</p>