Softmax
Use the softmax function to convert a neural network from binary to multiclass classification.
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Chapter Goals:
- Update the model to use the softmax function
- Perform multiclass classification
A. The softmax function
To convert the model to multiclass classification, we need to make a few changes to the metrics and training parameters. Previously, we used the sigmoid function to convert logits to probabilities, then rounded those probabilities to get a predicted label. However, now that there are multiple possible classes, we need to use the generalization of the sigmoid function, known as the softmax function.
The softmax function takes in a vector of numbers (logits for each class), and converts the numbers to a probability distribution. This means that the sum of the probabilities across all the classes equals 1, and each class's individual probability is based on how ...