Contents
What is threshold in confusion matrix?
We can set a threshold value to classify all the values greater than threshold as 1 and lesser then that as 0. That’s how the Y is predicted and we get ‘Y-predicted’. The default value for threshold on which we generally get a Confusion Matrix is 0.50.
What is the range of values for sigmoid function?
Sigmoid functions most often show a return value (y axis) in the range 0 to 1. Another commonly used range is from −1 to 1. A wide variety of sigmoid functions including the logistic and hyperbolic tangent functions have been used as the activation function of artificial neurons.
What is a threshold in classification?
The threshold governs the choice to turn a projected probability or scores into a class label. For normalized projected probabilities in the range of 0 to 1, the threshold is set to 0.5 by default.
When does a sigmoid function look like a threshold?
If we assume income more than 4000 USD is one class i.e 1 than less than 4000 USD is another class . then it looks like our sigmoid function formula. In fact , This is inner side of mechanism.
What is the boundary of the sigmoid function?
As per Andrew Ng’s Course, if you use the sigmoid activation, the outputs represent the probability of either outcome 0 or outcome 1. So the decision boundary is 0.5
How is the sigmoid function used in logistic regression?
Sigmoid function is used for this algorithm. However, Sigmoid function is same as linear equation. It divides into classes via threshold in probability outcome. The main advantage is here that we can set threshold as per business requirement.
How to define threshold in logistic regression function?
Let’s take all probabilities ≥ 0.5 = class 1 and all probabilities < 0 = class 0. This threshold should be defined depending on the business problem we were working. Here , Logistic Regression is made by manual class and evaluated them.We also use Logistic Regression class from sklearn library and evaluated them.