Create Your First Chart with pyG2

Installation

pip install pyG2

pyG2 only supports jupyter notebook. (Jupyterlab and Colab is not still supported.)

• Open jupyter notebook and create a new notebook file.

• Import G2 module:

  from pyG2 import G2
  

• Prepare the data set (Details of several cars from mtcars dataset):

  data =[
  {'name': 'Mazda RX4', 'mpg': 21.0, 'cyl': 6},
  {'name': 'Mazda RX4 Wag', 'mpg': 21.0, 'cyl': 6},
  {'name': 'Datsun 710', 'mpg': 22.8, 'cyl': 4},
  {'name': 'Hornet 4 Drive', 'mpg': 21.4, 'cyl': 6},
  {'name': 'Hornet Sportabout', 'mpg': 18.7, 'cyl': 8},
  {'name': 'Valiant', 'mpg': 18.1, 'cyl': 6},
  {'name': 'Duster 360', 'mpg': 14.3, 'cyl': 8},
  {'name': 'Merc 240D', 'mpg': 24.4, 'cyl': 4},
  {'name': 'Merc 230', 'mpg': 22.8, 'cyl': 4},
  {'name': 'Merc 280', 'mpg': 19.2, 'cyl': 6}
  ]
  

• Create the chart (Number of cylinders of each car):

  chart = G2.Chart(height=500,width=900)
  chart.data(data)
  chart.interval().position('name*cyl')
  chart.render()
  

Output:

Explaination of code

G2.Chart() generates a chart object which holds details of the chart. Height and weight are optional. (Default is 500pt, 400pt).

chart.data(data) provides data to the chart. There are two supported data formats: list of dictionaries as in the example or pandas.DataFrame. (Latter is recommended.)

chart.interval().position('name*cyl') specifies geometry and aesthetics of the chart. 'name*cyl' is the map that is represented in the chart. It is represented as a position. We choose interval geometry (bars) to visualize the chart.

chart.render() renders the chart to the notebook output.

Try Other Geometries

Use this code to generate a line chart:

chart = G2.Chart(height=500,width=900)
chart.data(data)
chart.line().position('name*cyl')
chart.render()

Output:

Try area, point plots. Hint: Change line in above code to these words.

Multiple plots

We shall create two graphs in one chart.

1. Name vs. Miles for Galon (mpg) : line
2. Name vs. No. of Cylinders (cyl) : interval (bar)

code:

chart = G2.Chart(height=500,width=900)
chart.data(data)
chart.line().position('name*cyl')
chart.interval().position('name*mpg')
chart.render()

Output:

Read our tutorials to learn how to generate various types of charts

Special Note:

If graphs are not visible when the notebook reloads, restart the kernal and run the code again.