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Hinton Diagrams | Weight Matrix Visualization

Introduction

MindMap

In this lab, we will learn how to use Hinton diagrams for visualizing weight matrices. Hinton diagrams are very useful when you want to visualize a 2D array, such as a weight matrix. Positive and negative values are represented by white and black squares, respectively, and the size of each square represents the magnitude of each value.

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Importing Libraries

We will start by importing the necessary libraries for this lab. In this case, we will need matplotlib and numpy.

import matplotlib.pyplot as plt
import numpy as np
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Defining the Hinton Function

Next, we will define a function called hinton that will generate the Hinton diagram. This function takes in a matrix, which is the weight matrix that we want to visualize, and a max_weight parameter, which is an optional parameter that specifies the maximum weight value for normalization purposes.

def hinton(matrix, max_weight=None, ax=None):
    """Draw Hinton diagram for visualizing a weight matrix."""
    ax = ax if ax is not None else plt.gca()

    if not max_weight:
        max_weight = 2 ** np.ceil(np.log2(np.abs(matrix).max()))

    ax.patch.set_facecolor('gray')
    ax.set_aspect('equal', 'box')
    ax.xaxis.set_major_locator(plt.NullLocator())
    ax.yaxis.set_major_locator(plt.NullLocator())

    for (x, y), w in np.ndenumerate(matrix):
        color = 'white' if w > 0 else 'black'
        size = np.sqrt(abs(w) / max_weight)
        rect = plt.Rectangle([x - size / 2, y - size / 2], size, size,
                             facecolor=color, edgecolor=color)
        ax.add_patch(rect)

    ax.autoscale_view()
    ax.invert_yaxis()
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Generating a Hinton Diagram

Now, we will generate a random weight matrix using numpy and then use the hinton function to generate the Hinton diagram.

if __name__ == '__main__':
    # Fixing random state for reproducibility
    np.random.seed(19680801)

    hinton(np.random.rand(20, 20) - 0.5)
    plt.show()
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Summary

In this lab, we learned how to use Hinton diagrams for visualizing weight matrices. We defined a function called hinton that generates the Hinton diagram and then used it to generate a random weight matrix. Hinton diagrams are very useful for visualizing 2D arrays, such as weight matrices, and can be used to quickly identify patterns and trends in the data.


πŸš€ Practice Now: Visualizing Weight Matrices With Hinton Diagrams


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