The book "Aggregation Functions: A Guide for Practitioners" is a comprehensive resource aimed at computer scientists, system architects, knowledge engineers, and programmers who need to combine multiple inputs into a single output. It provides an easy-to-use guide to various aggregation functions, focusing on practical applications rather than advanced mathematical theory. The authors, Dr. Gleb Beliakov, Dr. Ana Pradera, and Professor Tomasa Calvo, present the material in a way that does not require a deep mathematical background, making it accessible to practitioners. The book covers a wide range of aggregation functions, including averaging functions, conjunctive and disjunctive functions, and mixed functions. Each chapter includes formal definitions, important properties, and practical methods for fitting these functions to empirical data. The authors also introduce numerical tools such as interpolation, smoothing, and optimization techniques to help readers construct and evaluate aggregation functions. Key topics include: - **Introduction**: Overview of aggregation functions, their uses, and general properties. - **Averaging Functions**: Classical means, weighted quasi-arithmetic means, ordered weighted averaging (OWA), Choquet and Sugeno integrals. - **Conjunctive and Disjunctive Functions**: Triangular norms and conorms, copulas, and other conjunctive and disjunctive functions. - **Mixed Functions**: Uninorms, nullnorms, generated functions, T-s functions, symmetric sums, and ST-OWA functions. - **Choice and Construction**: Methods for selecting and constructing aggregation functions from empirical data. - **Interpolatory Type Aggregation Functions**: Construction based on spline functions and Lipschitz interpolation. - **Other Types of Aggregation and Additional Properties**: Exploring other aggregation methods and additional properties useful for specific applications. The book also includes a software package called AOTool, which can be used to fit aggregation functions to empirical data and visualize them. This practical guide is designed to help readers implement and apply aggregation functions effectively in their projects.The book "Aggregation Functions: A Guide for Practitioners" is a comprehensive resource aimed at computer scientists, system architects, knowledge engineers, and programmers who need to combine multiple inputs into a single output. It provides an easy-to-use guide to various aggregation functions, focusing on practical applications rather than advanced mathematical theory. The authors, Dr. Gleb Beliakov, Dr. Ana Pradera, and Professor Tomasa Calvo, present the material in a way that does not require a deep mathematical background, making it accessible to practitioners. The book covers a wide range of aggregation functions, including averaging functions, conjunctive and disjunctive functions, and mixed functions. Each chapter includes formal definitions, important properties, and practical methods for fitting these functions to empirical data. The authors also introduce numerical tools such as interpolation, smoothing, and optimization techniques to help readers construct and evaluate aggregation functions. Key topics include: - **Introduction**: Overview of aggregation functions, their uses, and general properties. - **Averaging Functions**: Classical means, weighted quasi-arithmetic means, ordered weighted averaging (OWA), Choquet and Sugeno integrals. - **Conjunctive and Disjunctive Functions**: Triangular norms and conorms, copulas, and other conjunctive and disjunctive functions. - **Mixed Functions**: Uninorms, nullnorms, generated functions, T-s functions, symmetric sums, and ST-OWA functions. - **Choice and Construction**: Methods for selecting and constructing aggregation functions from empirical data. - **Interpolatory Type Aggregation Functions**: Construction based on spline functions and Lipschitz interpolation. - **Other Types of Aggregation and Additional Properties**: Exploring other aggregation methods and additional properties useful for specific applications. The book also includes a software package called AOTool, which can be used to fit aggregation functions to empirical data and visualize them. This practical guide is designed to help readers implement and apply aggregation functions effectively in their projects.