# Questions tagged [sigmoid]

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### how does sigmoid activation implementation in tensorflow works?

I am running the following mnist implementation: ...
• 103
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### Is this an unusual distribution for a sigmoid output from a neural network?

Shown here is the histogram of around 130K predictions of my deep neural network that is classifying some financial data. This is on the dev set but a similar distribution is also seen on the train ...
• 103
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### Binary classification works with softmax, but not sigmoid

I am doing a binary classification problem for seizure classification. I split the data into Training, Validation and Test with the following sizes and shapes dataset_X = ...
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### Improvement of the Keras model for a regression task

I am trying to build an expectation model for my (19502,3) data using Keras Sequential model. This dataset has been generated using a parametric sweep in a simulation software. With this model, I want ...
1 vote
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### How do I calculate the New W1 and New W2?

You are training the following perceptron. The neuron in this perceptron has a sigmoid activation function. The sigmoid function is represented by the following equation: Using the update function ...
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### Logistic Regression mapping formula

Sigmoid function predicts the probability value which is between 0 & 1. What is the formula in logistic regression that maps the predicted probabilities to either 1 or 0?
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### Mapping values in Logistic Regression

When mapping probabilities obtained in logistic regression to 0s & 1s using the sigmoid function, we use a threshold value of 0.5. If the predicted probability lies above 0.5, then it gets mapped ...
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### Understanding intution behind sigmoid curve in the context of back propagation

I was trying to understand significance of S-shape of sigmoid / logistic function. The slope/derivative of sigmoid approaches zero for very large and very small input values. That is $σ'(z) ≈ 0$ for \$...
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1 vote
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### If the input to the autoencoder is normalized, do we need to use sigmoid on the last layer?

According to: https://stackoverflow.com/questions/65307833/why-is-the-decoder-in-an-autoencoder-uses-a-sigmoid-on-the-last-layer The last layer activation function contains sigmoid in order to the ...
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### Difference in performance Sigmoid vs. Softmax

For the same Binary Image Classification task, if in the final layer I use 1 node with Sigmoid activation function and ...
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### How to interpreter Binary Cross Entropy loss function?

I saw some examples of Autoencoders (on images) which use sigmoid as output layer and BinaryCrossentropy as loss function. The ...
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