title: Draw heatmap using python
body: <p>I am trying to draw heatmap using Jupyter notebook. My table consists of 10 colomns and a lot of rows. The first row is the names of the colomns. I am using plotly lib.</p>
  
  <pre><code>import plotly.offline as py
  import plotly.graph_objs as go
  import pandas as pd
  import numpy as np
  import pickle
  import matplotlib
  import matplotlib.pyplot as plt
  from pandas import ExcelWriter
  from pandas import ExcelFile    
  
  heatmap = go.Heatmap(
              z=dfs.corr(method='pearson').as_matrix(),
              x=dfs.columns,
              y=dfs.columns,
              colorbar=dict(title='Pearson Coefficient'),
          )
  
      layoutheat = go.Layout(title="title")
  
      figheat = go.Figure(data=[heatmap], layout=layoutheat)       
      py.iplot(figheat) 
  </code></pre>
  
  <p>dfs is dataframe.</p>
  
  <p>Instead of graphic I get a lot of line like this:</p>
  
  <p><em>'\ntrace = dict(\n        x = x, y = y, z = z,\n        type = "scatter3d",    \n        mode = \'markers\',\n        marker = dict( size=5, color=\'black\', line=dict(width=0) ) )\ndata = [trace]\n  \nlayout = dict(\n</em> etc</p>
  
  <p>What is the problem?</p>