mohd-faizy / Preprocess_ML

This repository hosts Python code that utilizes the Scikit-learn preprocessing API for data preprocessing. The code presents a comprehensive range of tools that handle missing data, scale data, encode categorical variables, and perform other functions.

Preprocessing

This repository hosts Python code that utilizes the Scikit-learn preprocessing API for data preprocessing. The code presents a comprehensive range of tools that handle missing data, scale data, encode categorical variables, and perform other functions.

what this Repo covers:

• Imputation of missing values using Imputer.
• Label encoding of categorical variables using LabelEncoder .
• One hot encoding of categorical variables using OneHotEncoder
• Standardization of features using StandardScaler .
• Normalization of features using Normalizer.
• Binning and discretization of features using Binarizer and KBinsDiscretizer.
• Polynomial feature expansion using PolynomialFeatures.
• Feature selection using SelectKBest, chi2, and SelectFromModel.

What is Data Preprocessing?

Data preprocessing is the process of preparing data for machine learning algorithms. The goal of data preprocessing is to transform raw data into a format that can be used by machine learning algorithms. Data preprocessing involves a range of tasks such as handling missing data, scaling data, encoding categorical variables, and performing other functions.

Preprocessing Technique	Description
Standardization or mean removal and variance scaling	Scaling the data to have a zero mean and unit variance. Useful when features have different scales.
Non-linear transformation	Applying a non-linear function to the data to make it more amenable to analysis.
Normalization	Scaling the data so that it falls within a certain range. Useful when the distribution of the data is skewed.
Encoding categorical features	Converting categorical data to numerical data using techniques like one-hot encoding and label encoding.
Discretization	Transforming continuous variables into discrete variables by creating bins or categories.
Imputation of missing values	Handling missing data by filling in reasonable estimates for missing values.
Generating polynomial features	Creating new features by taking combinations of existing features.
Custom transformers	Developing custom transformers to transform data into a format suitable for analysis by machine learning algorithms.
Outlier removal	Removing extreme values that are significantly different from other values in the dataset.
Feature selection	Identifying and selecting the most relevant features for the model, and discarding less relevant or redundant features.
Dimensionality reduction	Reducing the number of features in the dataset by projecting them onto a lower-dimensional space, while preserving most of the important information. Techniques like Principal Component Analysis (PCA) and t-SNE are used for this.
Feature scaling	Scaling the features so that they have similar ranges or magnitudes, to prevent certain features from dominating the others.
Feature engineering	Creating new features by combining or transforming existing features. This is often done to capture domain-specific knowledge and improve the performance of the model.
Text preprocessing	Converting raw text data into a format suitable for machine learning algorithms, by performing tasks like tokenization, stemming, lemmatization, stopword removal, and vectorization.
Image preprocessing	Preparing images for analysis by converting them into a common format, resizing or cropping them, and normalizing their pixel values.
Time series preprocessing	Handling time-dependent data by smoothing, differencing, or detrending the time series, or by aggregating the data into different time intervals.
Data augmentation	Creating new samples by applying random transformations to existing samples. This is often used in computer vision and natural language processing to increase the size of the dataset and improve the generalization of the model.

What is the Scikit-learn Preprocessing API?

The Scikit-learn preprocessing API provides a range of tools for data preprocessing. The preprocessing API includes tools for handling missing data, scaling data, encoding categorical variables, and performing other functions. The Scikit-learn preprocessing API is used by many machine learning algorithms in the Scikit-learn library.

API	Description
Binarizer	Binarizes continuous data by setting feature values above a threshold to 1 and those below it to 0. This is useful when you want to convert continuous data into a binary format for use in some algorithms.
FunctionTransformer	Constructs a transformer from an arbitrary callable. This allows you to apply any custom function to your data as a part of a scikit-learn pipeline.
KBinsDiscretizer	Bins continuous data into intervals using equal width or equal frequency. This transformer can be useful when you want to discretize a continuous variable into a categorical variable, e.g. to prepare it for use in a decision tree model.
KernelCenterer	Centers an arbitrary kernel matrix by subtracting the row and column means from each element. This is useful when you want to center a kernel matrix that has been constructed using some kernel function, e.g. in a support vector machine.
LabelBinarizer	Binarizes labels in a one-vs-all fashion, where each class is treated as a binary classification problem. This transformer is useful when you have a multi-class classification problem and want to convert your labels into a binary format.
LabelEncoder	Encodes target labels with a value between 0 and n_classes-1. This transformer is useful when you have a multi-class classification problem and want to convert your labels into a numerical format.
MultiLabelBinarizer	Transforms between an iterable of iterables and a multilabel format. This transformer is useful when you have a multi-label classification problem and want to convert your labels into a binary format.
MaxAbsScaler	Scales each feature by its maximum absolute value. This transformer is useful when you want to scale your features to a range between -1 and 1, but want to preserve the sparsity of sparse matrices.
MinMaxScaler	Scales each feature to a given range, typically [0, 1] or [-1, 1]. This transformer is useful when you want to scale your features to a specific range for use in some algorithms.
Normalizer	Normalizes samples individually to unit norm. This transformer is useful when you want to scale your samples to have a unit norm, which can be useful in some distance-based algorithms.
OneHotEncoder	Encodes categorical features as a one-hot numeric array. This transformer is useful when you have categorical features that need to be converted into a numerical format.
OrdinalEncoder	Encodes categorical features as an integer array. This transformer is useful when you have categorical features that need to be converted into a numerical format, but the order of the categories is important.
PolynomialFeatures	Generates polynomial and interaction features up to a specified degree. This transformer is useful when you want to add polynomial or interaction features to your data, e.g. to capture non-linear relationships.
PowerTransformer	Applies a power transform featurewise to make data more Gaussian-like. This transformer is useful when you have data that is not normally distributed and want to make it more amenable to certain statistical models.
QuantileTransformer	Transforms features using quantiles information. This transformer is useful when you want to transform your features to have a specified distribution, e.g. to make them more Gaussian-like or uniform.
RobustScaler	Scales features using statistics that are robust to outliers. This transformer is useful when you have data with outliers and want to scale your features
SplineTransformer	Generate univariate B-spline bases for features.
StandardScaler	Standardize features by removing the mean and scaling to unit variance.
add_dummy_feature	Augment dataset with an additional dummy feature.
binarize	Boolean thresholding of array-like or scipy.sparse matrix.
label_binarize	Binarize labels in a one-vs-all fashion.
maxabs_scale	Scale each feature to the [-1, 1] range without breaking the sparsity.
minmax_scale	Transform features by scaling each feature to a given range.
normalize	Scale input vectors individually to unit norm (vector length).
quantile_transform	Transform features using quantiles information.
robust_scale	Standardize a dataset along any axis.
scale	Standardize a dataset along any axis.
power_transform	Parametric, monotonic transformation to make data more Gaussian-like.

What is this Repository?

This repository contains Python code that utilizes the Scikit-learn preprocessing API for data preprocessing. The code presents a comprehensive range of tools that handle missing data, scale data, encode categorical variables, and perform other functions. The code is organized into modules that correspond to different data preprocessing tasks.

Contributing

This repository is open source and contributions are welcome. If you have any ideas for hacks or tips, or if you find any errors, please feel free to open an issue or submit a pull request.

License

This repository is licensed under the MIT License.

Thanks for checking out this repository! I hope you find it helpful.

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