title: Bubble plot or Heatmap in matplotlib
body: <p>I am trying to plot a dynamically size able bubble (scatter map). When I try to plot with random data I can very well plot. But when I am trying to parse my input file I am not able to plot. </p>
  
  <p>Input:</p>
  
  <pre><code>Nos,Place,Way,Name,00:00:00,12:00:00
  123,London,Air,Apollo,342,972
  123,London,Rail,Beta,2352,342
  123,Paris,Bus,Beta,545,353
  345,Paris,Bus,Rava,652,974
  345,Rome,Bus,Rava,2325,56
  345,London,Air,Rava,2532,9853
  567,Paris,Air,Apollo,545,544
  567,Rome,Rail,Apollo,5454,5
  876,Japan,Rail,Apollo,644,54
  876,Japan,Bus,Beta,45,57
  </code></pre>
  
  <p>Program:</p>
  
  <pre><code>import pandas as pd
  from pandas import DataFrame
  import pandas.io.data
  import matplotlib.pyplot as plt
  import numpy as np
  import seaborn as sns
  
  
  df=pd.read_csv('text_2.csv')
  
  
  #SIZE OF BUBBLES CHANGES
  
  fig = plt.figure()
  
  ax = fig.add_subplot(1,1,1)
  
  ax.scatter(df['Place'],df['Name'], s=df['00:00:00']) # Added third variable income as size of the bubble
  
  
  plt.show()
  </code></pre>
  
  <p>I am trying to put <code>Place</code> as <code>x axis</code> and <code>Name</code> as <code>y axis</code> and <code>Size</code> to be taken from the <code>count(00:00)</code>. Sizable bubble I could not find much of examples around. Any valuable suggestions is appropriated. Thanks in Advance. 
  Why do I get error at (00:00) column and how do I pass the values of that column ?</p>
  
  <p>Error:</p>
  
  <pre><code>    Traceback (most recent call last):
    File "Bubble_plot.py", line 18, in &lt;module&gt;
      ax.scatter(df['Place'],df['Name'], s=df['00:00:00']) # Added third variable income as size of the bubble
    File "/usr/lib/pymodules/python2.7/matplotlib/axes.py", line 6266, in scatter
      x, y, s, c = cbook.delete_masked_points(x, y, s, c)
    File "/usr/lib/pymodules/python2.7/matplotlib/cbook.py", line 1774, in delete_masked_points
      raise ValueError("First argument must be a sequence")
  ValueError: First argument must be a sequence
  </code></pre>