Quais são as vantagens do dimensionamento de recursos no ML?

There are several techniques for feature scaling in machine learning, each with its own advantages and use cases. Here are some common types of feature scaling: - Min-Max Scaling (Normalization) - Standardization (Z-score normalization) - Robust Scaling - Max Abs Scaling - Unit Vector Scaling (Vector Normalization) - Power Transformations - Quantile Transformation

This is great for interpretability of the coefficients as weights in linear models. It is also highly recommended in neural networks as it improves the accuracy. Normalisation can help to force differently scaled features to the same scale so the network will learn from all features.

feature scaling is a fundamental preprocessing step that contributes significantly to the stability, efficiency, and performance of machine learning models, particularly when working with diverse features of different scales and units.

To make sure that machine learning models are not inclined to specific features with large magnitude. The ML models which are distance based depends on similarities between features like KNN, ANN, SVM should be needed to be trained and tested after feature scaling. Scale invariant ML models like decision tree, decision forest can be used without feature scaling. Min-max normalisation, z-score normalisation, and feature standardization are common methods for feature scaling.

Feature scaling in machine learning offers several advantages: Improved Model Performance: Scaling features ensures that all features contribute equally to the model, preventing biases due to differences in scale. Faster Convergence: Scaling accelerates the convergence of optimization algorithms, allowing faster training of machine learning models. Enhanced Interpretability: Scaling helps in better interpretability of model coefficients or parameters, aiding in understanding feature importance. Mitigated Numerical Instabilities: It reduces the risk of numerical instabilities and overflow/underflow issues during computations in certain algorithms.

Feature scaling L1 and L2 can help in regularization by ensuring that all features are on a similar scale, preventing some features from dominating the regularization term. Algorithms that use distance metrics, such as k-means clustering or hierarchical clustering, are sensitive to the scale of the features. Feature scaling ensures that the distance calculations are not biased by the scale of the features, leading to more accurate clustering. Models that rely on gradient descent for optimization, such as linear regression and neural networks, can benefit from feature scaling. It helps prevent oscillation and convergence issues, making the optimization process more stable.

Feature scaling is useful when the algorithm makes decisions based on feature thresholds. When features have different units or scales, features with larger scales can dominate the feature importance calculations, and smaller-scale features may have less impact on the model. In these cases, feature scaling bring all in the features in the same range and allows algorithms to be impartial to any particular feature.

You can supplement the rules of thumb above with some trial and error to help you decide what to scale. Complete scaling and then evaluate your ML model's performance, then check score of the same metric without scaling.

In my experience, Feature scaling(FS) is particularly beneficial for algos that are sensitive to the magnitude of features, such as gradient descent in DL, SVN, and k-means clustering. FS generally recommended when features have different units or significantly different scales. E.g., if you're working with a dataset that includes both age & income, which have different ranges, feature scaling can be beneficial. However, FS are insensitive to tree-based models like decision trees & random forests. FS should be considered as a preprocessing step when dealing with numerical data and algorithms that are affected by feature magnitudes.

Feature scaling is essential when working with machine learning algorithms that are sensitive to the scale of features. Some algorithms that require feature scaling include k-nearest neighbors, support vector machines, and principal component analysis. If the features have different units or scales, it can lead to biased model performance.

To apply feature scaling to your data, follow these steps: Split your data into training and testing sets to prevent data leakage and overfitting. Choose the suitable feature scaling method based on your data's type, distribution, and range, as well as the algorithm you plan to use. Fit the chosen feature scaling method to the training set, calculating parameters like minimum, maximum, mean, standard deviation, or norm. Transform both the training and testing sets using the same feature scaling parameters. Train and evaluate your machine learning model using the scaled data as input.

To apply feature scaling in machine learning, it's crucial to choose the right method based on your data and algorithm's needs. You should first split your data into training and testing sets to prevent data leakage and overfitting. Then, select the appropriate scaling method, such as min-max scaling, standardization or normalization, depending on your feature characteristics. Fit the scaling method to the training set to compute necessary parameters and apply the same method to both the training and testing sets. By incorporating feature scaling into your workflow, you enhance algorithm stability, improve model convergence and achieve more consistent and interpretable results in your machine learning projects.

Popular techniques for feature scaling include Min-Max scaling, Z-score normalization, and Robust scaling. The choice of scaling method depends on the specific characteristics of the data and the requirements of the machine learning algorithm being used. The entire datasets are split into 70:30 / 80:20 ratio of training : test and various techniques such as min-max normalization , standardization are applied on the datasets ion order to scale them down in the same range so that various machine learning algorithms can be applied. Finally evaluate your model on test datasets (20 ratio split) and evaluate your performance.

I agree but , in other words, there are the steps to do ML scaling: 1. First and foremost Under the domain, think about the inputs and outputs of the solutions that we are trying to develop, and how the business is going to interpret the results. 2. Next comes to, collect and preserve the relevant data that we are trying to solve. This may be labelled data as well. 3. Perform EDA and feature engineering. 4. Perform different training algorithms ( model training) and choose which fits the best. Typically it’s a tedious task and takes long time. 5. Performance evaluation. 6. Finally deploy the model to end users.

FS is crucial for preprocessing data to make sure that features are on a similar scale. Common methods I would say, Min-Max Scaling, Standardization (Z-score scaling), Robust Scaling, & Log Transformation (LT). Min-Max Scaling normalizes features to a specific range (typically 0 to 1), making it suitable for algorithms that assume specific feature ranges. Standardization transforms data to have a mean of 0 & a SD of 1, making it suitable for normally distributed data. Robust Scaling is less sensitive to outliers and uses the interquartile range. LT compresses values & is useful for non-normally distributed data with wide-ranging features. selection depends on data distribution, algorithm requirements, & the presence of outliers.

Feature scaling is very important as : - It helps algorithms converge faster. This is especially true for gradient descent based algorithms, since they are able to optimise the cost function quicker. - In distance based algorithms such as K-means feature scaling improves performance by preventing features with larger values from dominating. - Feature scaling also helps with interpretability since it brings the magnitude of all features on the same scale. - Feature scaling can also improve the robustness to outliers, though this does not imply that feature scaling should be considered as a way to handle outliers.

The advantages of feature scaling in machine learning (ML) include – It ensures that features contribute equally to the model's prediction, preventing bias towards variables with larger scales. Feature scaling can improve the convergence speed of gradient descent algorithms by ensuring a smoother and faster path to the minimum. It enhances the performance of models like Support Vector Machines (SVM) and k-nearest neighbours (k-NN) that are sensitive to the range of data points. Algorithms that use distance measures, like k-NN and k-means clustering, benefit from feature scaling for more accurate results. It can also improve the interpretability of models by making the feature importance more comparable.

Advantages of feature scaling in ML models - 1. Improved Convergence and Stability: Feature scaling enhances the convergence and stability of gradient descent-based algorithms, such as neural networks and logistic regression. By normalizing the feature values, the algorithm can effectively navigate the optimization landscape, leading to a more stable and reliable model. 2. Reduced Bias: Without feature scaling, features with larger magnitudes can exert undue influence on the model's prediction, potentially leading to biased results. Scaling ensures that all features contribute proportionally. 3. Faster Optimization: Feature scaling can accelerate the optimization process, particularly for gradient descent algorithms.

From a “learning” standpoint, feature scaling prevents larger valued features from overpowering any features with smaller values. Essentially, leveling the playing field. From a computational standpoint, having smaller values speeds up model training vs. training on features with large values.

Improved Model Convergence: Scaling helps gradient-based optimization algorithms converge faster, as features are in a consistent range. Enhanced Model Performance: Scaling can lead to better model accuracy, especially in algorithms that rely on distance calculations. Interpretability: Scaled features are easier to interpret, as they are on a common scale, making it simpler to compare feature importance.

In my experience with deep learning, messing with how features are scaled doesn't usually change things a lot. But, we still need to be careful because some methods are sensitive to outliers. For instance, if we're using a scaling method like Min-Max and there's this one data point that's way bigger than the rest, it essentially diminishes the influence of in-distribution datapoints on the predictive capability.

Certain scaling methods, such as Min-Max scaling, can be sensitive to outliers. Outliers can disproportionately affect the scaling process, leading to a distortion of the entire scale. Not all algorithms are equally sensitive to the scale of features. While some models, like SVM and k-nearest neighbors, are highly sensitive, others, such as tree-based models (like decision trees and random forests), are less affected. It's essential to consider the specific algorithm and its sensitivity to feature scales. Different scaling methods may be more suitable for certain types of data or models. Choosing the wrong scaling method could potentially introduce bias or inaccuracies into the model.

These challenges mean that you will benefit from scrutinizing the need for scaling first. Before having to deal with this, first consider whether your modeling effort really needs scalingm

Scaling of the features can be done based on the data, problem and the operator used for applying the scaling technique. Normalization techniques are sensitive to outliers. If the feature values are bound between 0 and 1, then they may create smaller standard deviation, this in turn suppresses the effects of the outlier if that is inherent in the feature.

Data Leakage: Scaling should be applied only to the training data and then propagated to the test data to prevent data leakage. Loss of Interpretability: In some cases, scaling might make the original feature values less interpretable. Sensitive to Outliers: Scaling methods can be sensitive to outliers, which might require additional preprocessing.

Feature scaling in machine learning offers several advantages: Improved Model Performance: Scaling features ensures that all features contribute equally to the model, preventing biases due to differences in scale. Faster Convergence: Scaling accelerates the convergence of optimization algorithms, allowing faster training of machine learning models. Enhanced Interpretability: Scaling helps in better interpretability of model coefficients or parameters, aiding in understanding feature importance. Mitigated Numerical Instabilities: It reduces the risk of numerical instabilities and overflow/underflow issues during computations in certain algorithms.

Feature scaling in machine learning offers several advantages. It helps in bringing different features of the dataset onto a similar scale, preventing certain features from dominating others during model training. This, in turn, can lead to faster convergence and better performance, especially for algorithms sensitive to the scale of input features, such as gradient-based methods. Feature scaling also enhances the interpretability of models and can improve the accuracy of distance-based algorithms like k-nearest neighbors.

Feature scaling should be performed separately on the training and test datasets to avoid data leakage. Consider the nature of your data; for example, Min-Max scaling may not be suitable for data with outliers. Sometimes, feature scaling might not be necessary if your model is robust to different feature scales, such as tree-based models like decision trees or random forests. Always evaluate the impact of feature scaling on your specific model and dataset to determine its effectiveness.

Feature scaling does not mean all features contribute equally to a model's prediction as has been written elsewhere; this is not the case. It prevents issues related to disparate feature scales. Feature importance is determined by the model itself during training. It's quite possible in the end that some features contribute much more to a prediction, and others can be discarded. It is not correct to say feature scaling means all features contribute equally.