CI-ADDO-NEW: Stan, Scalable Software for Bayesian Modeling

该奖项旨在设计、编码、文档、测试、传播和维护Stan， Stan是一个可扩展的开源软件框架和编译器，用于高效和可扩展的贝叶斯统计建模。Stan是一个可扩展的、开源的、跨平台的软件框架，用于开发贝叶斯统计模型。贝叶斯建模的第一步是为所有感兴趣的量建立一个全概率模型。Stan通过提供用于指定概率模型的表达性和可扩展的领域特定编程语言，简化了这一过程。通过将模型规范编译成可执行代码，Stan完全自动化了贝叶斯推理的第二步，计算未观察到的数量的概率，例如模型参数和未来观察，条件是观察到的数据。第三步包括评估模型与数据的拟合程度以及对未知数据的预测。当模型易于编码，推理快速且自动计算时，就很容易迭代规范、拟合和评估步骤，从而完善科学的模型。Stan在算法和实现细节上都改进了现有的技术。Stan模型被编译成c++代码，而不是像它的前辈那样被动态地解释，这极大地提高了可伸缩性和效率。Stan为统计建模所需的函数提供了完整的算法微分库。这种方法将微积分中的链式法则应用到计算概率函数的程序中，以便有效而准确地计算导数（计算函数所需时间的一小倍，与维数无关）。这允许Stan完全自动化模型拟合阶段，只给出Stan建模语言中概率函数的规范。为了最大限度地提高Stan对科学界的可访问性，它正在使用符合标准的c++进行编码，以便它可以在Windows， Macintosh和Unix/Linux下运行。为了使Stan更容易运行，它可以从R、MATLAB和Python这三个最流行的数值分析平台（包括探索和绘图）中调用。

This award is to design, code, document, test, dissememinate, and maintain Stan,an extensibleopen-source software framework and compiler for efficient and scalable Bayesian statistical modeling.Stan is an extensible, open-source, cross-platform software framework for developing Bayesian statisticalmodels. The first step in Bayesian modeling is setting up a full probability model for all quantities ofinterest. Stan facilitates this process by providing an expressive and extensible domain-specificprogramming language for specifying probabilistic models. By compiling a model specification intoexecutable code, Stan fully automates the second step of Bayesian inference, calculating the probabilitiesof unobserved quantities, such as model parameters and future observations, conditional on observed data.The third step involves evaluating the fit of the model to the data and its predictions for unseen data.When the model is easy to encode and inferences are fast and automatic to compute, it is easy to iteratethe specification, fit and evaluation steps in order to refine the scientific model.Stan improves on the existing state of the art in both algorithmic and implementation details. Rather thanbeing interpreted on the fly like its predecessors, Stan models are compiled to C++ code, whichdramatically improves both scalability and efficiency. Stan provides a full algorithmic differentiation library for the functions required for statistical modeling. This method applies the chain rule from calculus to the program computing the probability function in order to calculate derivatives efficiently and accurately (a small multiple of the time taken to compute thefunction, independently of dimensionality). This allows Stan to fully automate the model fitting stagegiven only a specification of the probability function in Stan's modeling language.To maximize Stan's accessibility to the scientific community, it is being coded using standards-compliantC++, so that it will run under Windows, Macintosh, and Unix/Linux. To make running Stan even easier,it is callable from R, MATLAB, and Python, the three most popular platforms for numerical analysis,including exploration and plotting.