The Surrogate Modeling Toolbox (SMT) is an open-source Python package that offers a collection of surrogate modeling methods, sampling techniques, and a set of sample problems. This paper presents SMT 2.0, a major new release of SMT that introduces significant upgrades and new features to the toolbox. This release adds the capability to handle mixed-variable surrogate models and hierarchical variables. These types of variables are becoming increasingly important in several surrogate modeling applications. SMT 2.0 also improves SMT by extending sampling methods, adding new surrogate models, and computing variance and kernel derivatives for Kriging. This release also includes new functions to handle noisy and use multifidelity data. To the best of our knowledge, SMT 2.0 is the first open-source surrogate library to propose surrogate models for hierarchical and mixed inputs. This open-source software is distributed under the New BSD license.

翻译：代理建模工具箱（SMT）是一个开源Python包，提供了一系列代理建模方法、采样技术以及一组示例问题。本文介绍了SMT 2.0——该工具箱的重大新版本，引入了显著升级和新功能。此版本新增了对混合变量代理模型和分层变量的处理能力，这类变量在多种代理建模应用中日益重要。SMT 2.0还通过扩展采样方法、添加新代理模型以及计算克里金法的方差和核导数进行了改进。此外，新版本包含了处理噪声数据和多保真度数据的功能。据我们所知，SMT 2.0是首个为分层和混合输入提供代理模型的开源代理库。该开源软件基于新BSD许可证分发。