Updated maths formulas

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Manish kumar gupta 2024-05-31 12:07:34 +05:30 zatwierdzone przez GitHub
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@ -12,7 +12,7 @@ MSE is one of the most commonly used cost functions, particularly in regression
**Mathematical Formulation:** **Mathematical Formulation:**
The MSE is defined as: The MSE is defined as:
$$ MSE = \frac{1}{n} \sum_{i=1}^{n} (y_i - \hat{y}_i)^2 $$ $$MSE = \frac{1}{n} \sum_{i=1}^{n} (y_i - \hat{y}_i)^2$$
Where: Where:
- \( n \) is the number of samples. - \( n \) is the number of samples.
- \( y_i \) is the actual value. - \( y_i \) is the actual value.
@ -41,7 +41,7 @@ MAE is another commonly used cost function for regression tasks. It measures the
**Mathematical Formulation:** **Mathematical Formulation:**
The MAE is defined as: The MAE is defined as:
$$ MAE = \frac{1}{n} \sum_{i=1}^{n} |y_i - \hat{y}_i| $$ $$MAE = \frac{1}{n} \sum_{i=1}^{n} |y_i - \hat{y}_i|$$
Where: Where:
- \( n \) is the number of samples. - \( n \) is the number of samples.
- \( y_i \) is the actual value. - \( y_i \) is the actual value.
@ -70,8 +70,11 @@ def mean_absolute_error(y_true, y_pred):
Cross-entropy loss is commonly used in binary classification problems. It measures the dissimilarity between the true and predicted probability distributions. Cross-entropy loss is commonly used in binary classification problems. It measures the dissimilarity between the true and predicted probability distributions.
**Mathematical Formulation:** **Mathematical Formulation:**
For binary classification, the cross-entropy loss is defined as: For binary classification, the cross-entropy loss is defined as:
$$ \text{Cross-Entropy} = -\frac{1}{n} \sum_{i=1}^{n} [y_i \log(\hat{y}_i) + (1 - y_i) \log(1 - \hat{y}_i)] $$
$$\text{Cross-Entropy} = -\frac{1}{n} \sum_{i=1}^{n} [y_i \log(\hat{y}_i) + (1 - y_i) \log(1 - \hat{y}_i)]$$
Where: Where:
- \( n \) is the number of samples. - \( n \) is the number of samples.
- \( y_i \) is the actual class label (0 or 1). - \( y_i \) is the actual class label (0 or 1).
@ -100,8 +103,11 @@ def binary_cross_entropy(y_true, y_pred):
For multiclass classification problems, the cross-entropy loss is adapted to handle multiple classes. For multiclass classification problems, the cross-entropy loss is adapted to handle multiple classes.
**Mathematical Formulation:** **Mathematical Formulation:**
The multiclass cross-entropy loss is defined as: The multiclass cross-entropy loss is defined as:
$$ \text{Cross-Entropy} = -\frac{1}{n} \sum_{i=1}^{n} \sum_{c=1}^{C} y_{i,c} \log(\hat{y}_{i,c}) $$
$$\text{Cross-Entropy} = -\frac{1}{n} \sum_{i=1}^{n} \sum_{c=1}^{C} y_{i,c} \log(\hat{y}_{i,c})$$
Where: Where:
- \( n \) is the number of samples. - \( n \) is the number of samples.
- \( C \) is the number of classes. - \( C \) is the number of classes.
@ -131,8 +137,11 @@ def categorical_cross_entropy(y_true, y_pred):
Hinge loss is commonly used in support vector machines (SVMs) for binary classification tasks. It penalizes misclassifications by a linear margin. Hinge loss is commonly used in support vector machines (SVMs) for binary classification tasks. It penalizes misclassifications by a linear margin.
**Mathematical Formulation:** **Mathematical Formulation:**
For binary classification, the hinge loss is defined as: For binary classification, the hinge loss is defined as:
$$ \text{Hinge Loss} = \frac{1}{n} \sum_{i=1}^{n} \max(0, 1 - y_i \cdot \hat{y}_i) $$
$$\text{Hinge Loss} = \frac{1}{n} \sum_{i=1}^{n} \max(0, 1 - y_i \cdot \hat{y}_i)$$
Where: Where:
- \( n \) is the number of samples. - \( n \) is the number of samples.
- \( y_i \) is the actual class label (-1 or 1). - \( y_i \) is the actual class label (-1 or 1).
@ -165,17 +174,16 @@ Huber loss is a combination of MSE and MAE, providing a compromise between the t
The Huber loss is defined as: The Huber loss is defined as:
$$ $$\text{Huber Loss} = \frac{1}{n} \sum_{i=1}^{n} \left\{
\text{Huber Loss} = \frac{1}{n} \sum_{i=1}^{n} \left\{
\begin{array}{ll} \begin{array}{ll}
\frac{1}{2} (y_i - \hat{y}_i)^2 & \text{if } |y_i - \hat{y}_i| \leq \delta \\ \frac{1}{2} (y_i - \hat{y}_i)^2 & \text{if } |y_i - \hat{y}_i| \leq \delta \\
\delta(|y_i - \hat{y}_i| - \frac{1}{2} \delta) & \text{otherwise} \delta(|y_i - \hat{y}_i| - \frac{1}{2} \delta) & \text{otherwise}
\end{array} \end{array}
\right. \right.$$
$$
Where: Where:
- \( n \) is the number of samples. - \( n \) is the number of samples.
- \( \delta \) is a threshold parameter. - \(delta\) is a threshold parameter.
**Advantages:** **Advantages:**
- Provides a smooth loss function. - Provides a smooth loss function.
@ -200,8 +208,11 @@ def huber_loss(y_true, y_pred, delta):
Log-Cosh loss is a smooth approximation of the MAE and is less sensitive to outliers than MSE. It provides a smooth transition from quadratic for small errors to linear for large errors. Log-Cosh loss is a smooth approximation of the MAE and is less sensitive to outliers than MSE. It provides a smooth transition from quadratic for small errors to linear for large errors.
**Mathematical Formulation:** **Mathematical Formulation:**
The Log-Cosh loss is defined as: The Log-Cosh loss is defined as:
$$ \text{Log-Cosh Loss} = \frac{1}{n} \sum_{i=1}^{n} \log(\cosh(y_i - \hat{y}_i)) $$
$$\text{Log-Cosh Loss} = \frac{1}{n} \sum_{i=1}^{n} \log(\cosh(y_i - \hat{y}_i))$$
Where: Where:
- \( n \) is the number of samples. - \( n \) is the number of samples.
@ -224,4 +235,4 @@ def logcosh_loss(y_true, y_pred):
These implementations provide various options for cost functions suitable for different machine learning tasks. Each function has its advantages and disadvantages, making them suitable for different scenarios and problem domains. These implementations provide various options for cost functions suitable for different machine learning tasks. Each function has its advantages and disadvantages, making them suitable for different scenarios and problem domains.
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