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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How can I find a good fit for my function?
I have a set of data at which I would like to fit a curve to. However, I'm having difficulties with finding the right equation type. I'm guessing it's a type of sigmoidal function.
I have tried several forms, but none of them seem to fit…
Yoni Verhaegen
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Tensorflow: Normalizing unbounded data
Normally when people normalize a data set, they tend to do something like:
Normalize Equation
My problem with using this technique though, is that my data is not bounded and I really want to avoid imposing an artificial upper or lower bound to my…
Kilian Liss
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why this code doesn't give me plot line (without error)?
I wrote this piece of code for plotting the 'Theoretical probability of a successful search versus Jaccard similarity' figure. The output is an empty plot. I don't know what should I change. the original function is in the picture I have replaced…
samira F
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How to Dynamically fit sigmoid growth curve for crop plants?
This is the typical Crop Growth Curve
The general equation/function for the sigmoid curve are, as in the function below 1 2
def sigmoid(x):
y = (1 / (1 + np.exp(-x)))
return (y)
I want that during any crop period starting from day 1, to…
Abhilash Singh Chauhan
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Fitting a sigmoid curve using a logistic function in R
I have data that follows a sigmoid curve and I would like fit a logistic function to extract the three (or two) parameters for each participant. I have found some methods online, but I'm not sure which is the correct option.
This tutorial explains…
Martina Kavanová
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How to make a Sigmoid function work on tensors
I am trying to build a logistic regression model and I implemented a sigmoid function from scratch using python. It works on regular integers and floats but does not work on individual values in tensors.
def sigmoid(z):
return 1/(1 +…
Larry Abecid
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how to remove these loops in python for sigmoid function
def sigmoid(a):
g = a
for i in range(a.shape[0]):
for j in range(a.shape[1]):
if a[i][j] >= 0:
z = np.exp(-a[i][j])
g[i][j] = 1 / (1 + z)
else:
z =…
Umme Ammarah
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How does logistic regression build Sigmoid curve from categorical dependent variable?
I'm exploring the Scikit-learn logistic regression algorithm. I understand that as part of the training, the algorithm builds a regression curve where the y-variable ranges from 0 to 1 (sigmoid S-curve). The y-variable is a continuous variable here…
museshad
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How can I calculate cross-entropy on a sigmoid neural network binary outcome?
I'm currently building a NN from scratch where we want to identify based on two input variables (X_1 and X_2) what their output will be (0 or 1). I have 2 hidden layers with sigmoid activation on all neurons however I get stuck when calculating the…
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Understanding neural network output >1 with sigmoid activation function
I'm experimenting with a model combining a convolutional neural network with a linear model. Here is a simplified version of it:
from tensorflow.keras import Sequential
from tensorflow.keras.experimental import WideDeepModel,…
lmm_5000
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2 answers
Need help in generating and the cost for a gradient descent function
I was following Andre Ng's Course on Natural Language Processing, Week 1 and trying to find the components of a function that is calculating a gradient Descent.
The GradientDescent function is given as such:
# UNQ_C2 (UNIQUE CELL IDENTIFIER, DO NOT…
Johnny
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fitting a group of sigmoids with different models with least_squares()?
For a series of experiments measured at different time points, I'm trying to compare fits that fixed parameters for all experiments with fits that have an individual set of parameters per experiment, using an information criterion (like Akaike IC).…
alle_meije
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val_loss and loss not decreasing u-net
I am training a U-NET model on 238 satellite images.
my val_loss is not decreasing below 0.3, despite of the different architectures that I…
Elouafi
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TypeError: cannot cast array data from dtype('float64) to dtype('
class SigmoidNeuron:
def __init__(self):
self.w=None
self.b=None
def perceptron(self,x):
return np.dot(x,self.w.T)+self.b
def sigmoid(self,x):
return 1.0/(1.0+np.exp(-x))
def grad_w(self,x,y):
…
Manas Chand
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Sigmoid for regression
i just started with data-science, so if this is a very dumb question then please excuse me...
So, i just learnt about the sigmoid neuron, and learnt that its range is [0, 1].
The question i have is that how can it be used in regression tasks, for…
DS3a
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