A sigmoid function is a mathematical function having an "S" shape (sigmoid curve). Often, sigmoid function refers to the special case of the logistic function defined by the formula S ( t ) = 1 / (1 + e^-t)
Sigmoid function (Wikipedia)
Questions tagged [sigmoid]
256 questions
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What Is the importance of using Relu?
I get confused with the activation functions. why we widely use the Relu function also at the end it's mapping will be a line? Using the sigmoid and tanh make the decision boundary to be squiggle which will fit the data well but, relu map a line(…
aya
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Parameters that denote the dynamic range, symmetry and slope of the sigmoid function respectively in software WEKA
I need the three parameters that denote the dynamic range, symmetry and slope of the sigmoid function respectively in software WEKA. I've alread search on books, papers and manuals without succesfull.
I want to implement a neural network and i need…
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1 answer
Why my tensorflow model is not learning in logistic regression - binary classification problem?
I am using the following code in tensorflow to fit breast cancer dataset for a binary classification problem. The dataset has 30 features to predict cancer or not. The model is as below:
def loss(y, y_pred):
return…
Sayan Dey
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Two neural networks - combine sigmoid outputs
I have two different neural network architectures. Both of them are for image segmentation. I run single input through both of them and got two sigmoid outputs (x and y).
I want to combine them to get the best possible result, but I am unsure…
Martin Perry
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Neural network with sigmoid function always get value closer to 0.5 fo XOR
I am practicing with neural network from scratch to handle XOR problem. However, the neural network output always getting close to 0.5 no matter what input it received.
Here is my code
import numpy as np
import matplotlib.pyplot as plt
from…
ryan chandra
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Choosing activation functions for Iris classification dataset
I am trying to build a neural network from scratch, so this means I will only be using numpy and pandas for defining the my neural network class. I tried appropriating some code that chatgpt gave me but its so buggy that I have decided to start from…
user8083
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Why does my logistic regression using sklearn not look like sigmoid
I tried to create a logistic regression model and then plot it, the first try didn't really work out and I got something like this:
However then I realized that my data is imbalanced (around 85% are 1s a the rest are 0s), so I changed my model to…
Sam333
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The neural network after several training epochs has too large sigmoid values and does not learn
I'm implementing a fully connected neural network for MNIST (not convolutional!) and I'm having a problem. When I make multiple forward passes and backward passes, the exponents get abnormally high and python is unable to calculate them. It seems to…
Амур Дзагкоев
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Sigmoid function returning 2
I just started learning about neural networks and I'm using the sigmoid function.
Here's the implementation :
def sigmoid(x):
return 1/1+(np.exp(-x))
then I have my network :
def make_predictions2(previousPrice, currentPrice, weight1, weight2,…
Lalaryk
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"No module named 'lab_utils_common'"
I was trying to run this program below but it's showing the error "No module named 'lab_utils_common'", what can I do to solve this problem?
import numpy as np
import matplotlib.pyplot as plt
from lab_utils_common import plot_data, sigmoid,…
Adib Reza
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How to improve 4-parameter logistic regression curve_fit?
I am trying to fit a 4 parameter logistic regression to a set of data points in python with scipy.curve_fit. However, the fit is quite bad, see below:
import matplotlib.pyplot as plt
import seaborn as sns
import numpy as np
from scipy.optimize…
minty
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0 answers
Should I use from_logits on AUC keras metric with sigmoid activation function?
I'm currently implementing a convolutional neural network model that outputs binary classification (true or false), and the labels are all either 0 or 1. When using the "sigmoid" activation function for the final dense layer, I was wondering whether…
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1 answer
Siamese Network in Tensorflow -- Changing Sigmoid Activiation Cutoffs
I've built the siamese network from the PyImageSearch.com tutorial here:
https://pyimagesearch.com/2020/11/30/siamese-networks-with-keras-tensorflow-and-deep-learning/
I'm augmenting the CNN to detect whether an image is identical (instead of the…
mjasilver
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How to pull out the actual probability values from logistic regression curve of a model?
I am interested to extract the actual probability values of logistic regression model using python. That is the values in between 1 and 0 as shown in the figure with pink color.enter image description here
my targets are binary classifiers
Abdur Rasheed
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Four parameters logistic regression derivative
Good Evening,
I fitted a four parameter logistic curve using R nls function with the following equation:
y = alpha + lambda/(1+exp(-beta(x-mu))
I would like to determine the maximum slope of this curve and for this I would like to compute the…
