Balanced Binning Reference

Frequently, machine learning problems in the real world suffer from the curse of dimensionality; you have fewer training instances than you’d like and the predictive signal is distributed (often unpredictably!) across many different features.

Sometimes when the your target variable is continuously-valued, there simply aren’t enough instances to predict these values to the precision of regression. In this case, we can sometimes transform the regression problem into a classification problem by binning the continuous values into makeshift classes.

To help the user select the optimal number of bins, the BalancedBinningReference visualizer takes the target variable y as input and generates a histogram with vertical lines indicating the recommended value points to ensure that the data is evenly distributed into each bin.

Visualizer	BalancedBinningReference
Quick Method	balanced_binning_reference()
Models	Classification
Workflow	Feature analysis, Target analysis, Model selection

from yellowbrick.datasets import load_concrete
from yellowbrick.target import BalancedBinningReference

# Load the concrete dataset
X, y = load_concrete()

# Instantiate the visualizer
visualizer = BalancedBinningReference()

visualizer.fit(y)        # Fit the data to the visualizer
visualizer.show()        # Finalize and render the figure

(Source code, png, pdf)

Quick Method

The same functionality above can be achieved with the associated quick method balanced_binning_reference. This method will build the BalancedBinningReference object with the associated arguments, fit it, then (optionally) immediately show it.

from yellowbrick.datasets import load_concrete
from yellowbrick.target import balanced_binning_reference

# Load the dataset
X, y = load_concrete()

# Use the quick method and immediately show the figure
balanced_binning_reference(y)

(Source code, png, pdf)

See also

To learn more, please read Rebecca Bilbro’s article “Creating Categorical Variables from Continuous Data.”

API Reference

Implements histogram with vertical lines to help with balanced binning.

class yellowbrick.target.binning.BalancedBinningReference(ax=None, target=None, bins=4, **kwargs)

Bases: TargetVisualizer

BalancedBinningReference generates a histogram with vertical lines showing the recommended value point to bin your data so they can be evenly distributed in each bin.

Parameters

axmatplotlib Axes, default: None

This is inherited from FeatureVisualizer and is defined within BalancedBinningReference.

targetstring, default: “y”

The name of the y variable

binsnumber of bins to generate the histogram, default: 4

kwargsdict

Keyword arguments that are passed to the base class and may influence the visualization as defined in other Visualizers.

Notes

These parameters can be influenced later on in the visualization process, but can and should be set as early as possible.

Examples

>>> visualizer = BalancedBinningReference()
>>> visualizer.fit(y)
>>> visualizer.show()

Attributes

bin_edges_binning reference values

draw(y, **kwargs)

Draws a histogram with the reference value for binning as vertical lines.

Parameters

yan array of one dimension or a pandas Series

finalize(**kwargs)

Adds the x-axis label and manages the tick labels to ensure they’re visible.

Parameters

kwargs: generic keyword arguments.

Notes

Generally this method is called from show and not directly by the user.

fit(y, **kwargs)

Sets up y for the histogram and checks to ensure that y is of the correct data type. Fit calls draw.

Parameters

yan array of one dimension or a pandas Series

kwargsdict

keyword arguments passed to scikit-learn API.

yellowbrick.target.binning.balanced_binning_reference(y, ax=None, target='y', bins=4, show=True, **kwargs)

BalancedBinningReference generates a histogram with vertical lines showing the recommended value point to bin your data so they can be evenly distributed in each bin.

Parameters

yan array of one dimension or a pandas Series

axmatplotlib Axes, default: None

This is inherited from FeatureVisualizer and is defined within BalancedBinningReference.

targetstring, default: “y”

The name of the y variable

binsnumber of bins to generate the histogram, default: 4

showbool, default: True

If True, calls show(), which in turn calls plt.show(). However, you cannot call plt.savefig from this signature, nor clear_figure. If False, simply calls finalize().

kwargsdict

Keyword arguments that are passed to the base class and may influence the visualization as defined in other Visualizers.

Returns

visualizerBalancedBinningReference

Returns fitted visualizer