2.1.9.1.Choropleth Maps - USA

1. 使用library

import plotly.plotly as py
import plotly.graph_objs as go 
from plotly.offline import download_plotlyjs,init_notebook_mode,plot,iplot
init_notebook_mode(connected = True)

2.基本操作

• Choropleth Map的兩個要素:

  • Data

    • 指定locationmode = 'USA-states'

      data = dict(type = 'choropleth', 
        locations = ['AZ', 'CA', 'NY'], 
        locationmode = 'USA-states', 
        colorscale = 'Portland', 
        text = ['Arizona', 'Cali', 'New York'], 
        z = [1.0 , 2.0, 3.0], 
        colorbar = {'title': 'colorbar title goes here'})

  • Layout

    • 在geo中指定'scope': 'usa'

      layout = dict(geo={'scope': 'usa'})

• 製作Choropleth Map

choromap = go.Figure(data = [data], layout = layout)
iplot(choromap)

3.從實際資料中繪製Choropleth Map

• 讀取資料

  • 可在資料中放入想要顯示的country code, z值 (數量), label

    import pandas as pd
    df = pd.read_csv('2011_US_AGRI_Exports')
    df.head()

    
• Choropleth Map的兩個要素 Data, Layout

    data = dict(type = 'choropleth',
           colorscale = 'YIOrRd',
           locations = df['code'],
           locationmode = 'USA-states',
           z = df['total exports'],
           text = df['text'],
           marker = dict(line = dict(color = 'rgb(255, 255, 255)', width = 2)), 
           colorbar = {'title': 'Millions USD'})
   layout = dict(title = '2011 US Agiculture Exports bt states', 
              geo = dict(scope = 'usa', showlakes = True, lakecolor = 'rgb(85, 173, 240)'))

• 製作Choropleth Map

choromap2 = go.Figure(data = [data], layout = layout)
iplot(choromap2)