What is Stacked Area Plot?
Stacked area charts are extension of area charts which evaluates multiple groups in single chart. An area graph represents change in quantities of one or more groups over time. Using stackplot() function of matplotlib library to plot customized stacked area plot in python.
In this article, I will explain you about how to draw customized stacked area plot in python.
Using Parameters for Customizing Area Chart
Parameters using matplotlib.pyplot to customize stacked area plot are given below
Parameters
----------
x : 1d array of dimension N
y : 2d array (dimension MxN), or sequence of 1d arrays (each dimension 1xN)
The data is assumed to be unstacked. Each of the following
calls is legal::
stackplot(x, y) # where y is MxN
stackplot(x, y1, y2, y3, y4) # where y1, y2, y3, y4, are all 1xNm
baseline : {'zero', 'sym', 'wiggle', 'weighted_wiggle'}
Method used to calculate the baseline:
- ``'zero'``: Constant zero baseline, i.e. a simple stacked plot.
- ``'sym'``: Symmetric around zero and is sometimes called
'ThemeRiver'.
- ``'wiggle'``: Minimizes the sum of the squared slopes.
- ``'weighted_wiggle'``: Does the same but weights to account for
size of each layer. It is also called 'Streamgraph'-layout. More
details can be found at http://leebyron.com/streamgraph/.
labels : Length N sequence of strings
Labels to assign to each data series.
colors : Length N sequence of colors
A list or tuple of colors. These will be cycled through and used to
colour the stacked areas.
**kwargs
All other keyword arguments are passed to `Axes.fill_between()`.
Parameters using pandas to customize area plot
Parameters
----------
x : label or position, optional
Coordinates for the X axis. By default uses the index.
y : label or position, optional
Column to plot. By default uses all columns.
stacked : bool, default True
Area plots are stacked by default. Set to False to create a
unstacked plot.
**kwargs
Additional keyword arguments are documented in
:meth:`DataFrame.plot`.
Installation of Packages
We will need numpy, matplotlib and seaborn packages to plot customized stacked area chart in python. If you don’t have these packages installed on your system, install it using below commands.
pip install numpy pip install matplotlib pip install seaborn
Customize Stacked Area Plot in Python
Let’s see an example to plot customize stacked area chart using seaborn color palette.
Installation of Packages
We will need numpy, matplotlib and seaborn packages to plot customized stacked area graph. Install packages using below command.
pip install numpy pip install matplotlib pip install seaborn
Import libraries
Import numpy, matplotlib and seaborn libraries in our python code to get started with plotting stacked area graph.
import numpy as np import matplotlib.pyplot as plt import seaborn as sns
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Prepare dataset
We will need x and y axis dataset values to plot stacked area chart.
Lets create dataset for x using Numpy arange() to get array object evenly spaces values within given range and for the 5 values of x we have assigned list of three list of 5 values representing three separate groups in y variable.
# Create dataset for X and Y axis x=np.arange(1,6) y=[ [1,4,3,5,9], [2,3,9,6,10], [2,8,10,8,12] ]
Plot Stacked Area chart using stackplot()
We declare a variable pal as set1 color palette from seaborn. Using matplotlib.pyplot stackplot() function to plot customized stacked area plot in python.
The values of x and y dataset are assigned in stackplot(). We have assigned a list to lables parameter, assigned pal parameter to colors and alpha as 0.4 for transparency.
We have assigned the location of legends as upper left in plot.
pal = sns.color_palette("Set1")
plt.stackplot(x,y, labels=['A','B','C'], colors=pal, alpha=0.4)
plt.legend(loc='upper left')
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Show Stacked Area Chart
Using Matplotlib show() function to show the graphical view of area chart.
plt.show()
Stacked Area plot Python Code
Use below customized stacked area plot in python using Matplotlib source code
# library
import numpy as np
import matplotlib.pyplot as plt
import seaborn as sns
# Create dataset for X and Y axis
x=np.arange(1,6)
y=[ [1,4,3,5,9], [2,3,9,6,10], [2,8,10,8,12] ]
# use a known color palette
pal = sns.color_palette("Set1")
plt.stackplot(x,y, labels=['A','B','C'], colors=pal, alpha=0.4 )
plt.legend(loc='upper right')
plt.show()
Customized Stacked Area Plot Output
Customized Stacked Area plot in Python
Let’s see an example to customize stacked area chart using own color palette.
Installation of Packages
We will require numpy and matplotlib packages installed on our system to plot stacked area plot. If we don’t have packages installed, we can install packages with the command below.
pip install numpy pip install matplotlib
Import libraries
We will import numpy and matplotlib libraries to plot stacked area plot. We have imported the numpy library as np and matplotlib.pyplot library as plt to reduce the complexity of code.
import numpy as np import matplotlib.pyplot as plt
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Prepare dataset
We have created variables x and y as datasets for stacked area plot using matplotlib stackplot() function.
Let’s create dataset for x using Numpy arange() to get array object evenly spaces values within given range and Y dataset having three list of 5 values.
# Create dataset for X and y axis x=np.arange(1,6) y=[ [1,4,3,5,9], [2,3,9,6,10], [2,8,10,8,12] ]
Plot Stacked Area chart
We will be creating our own color list to create palette and used use it in stacked area chart.
The values of x and y dataset are assigned in stackeplot() function we have assigned color of plot as variable pal having palette and alpha as 0.4 for transparency.
We have assigned the location of legends as upper left in plot.
pal = ["#9b59b6", "#e74c3c", "#34495e", "#2ecc71"] plt.stackplot(x,y, labels=['A','B','C'], colors=pal, alpha=0.4) plt.legend(loc='upper left')
Stacked Area Plot Python Source Code
Use below entire source code to plot stacked area plot in python using Matplotlib.
# import libraries import numpy as np import matplotlib.pyplot as plt # Create dataset for x and y axis x=np.arange(1,6) y=[ [1,4,3,5,9], [2,3,9,6,10], [2,8,10,8,12] ] # create your palette pal = ["#9b59b6", "#e74c3c", "#34495e", "#2ecc71"] plt.stackplot(x,y, labels=['A','B','C'], colors=pal, alpha=0.4 ) plt.legend(loc='upper right')
Stacked Area Chart output
Conclusion
I hope you found above article on customized stacked area plot in python using matplotlib package informative and educational.