相关实验视频
Updated: Jul 4, 2026

13:51
Cross-Modal Multivariate Pattern Analysis
Published on: November 9, 2011
探路者:平行准牛顿变化推理推理
Lu Zhang1, Bob Carpenter2, Andrew Gelman3
1Division of Biostatistics, Department of Population and Public Health Sciences, University of Southern California, Los Angeles, CA 90032, USA.
概括
路径探测器是一种新的变化方法,用于从概率密度中高效的近似采样. 与ADVI和HMC等现有方法相比,它提供了更好的准确性和速度.
科学领域:
- 计算统计学 计算统计学
- 贝叶斯的推理是贝叶斯的推理.
- 机器学习 机器学习
背景情况:
- 变量推理方法对于在机器学习和统计学中近似复杂的概率分布至关重要.
- 现有的方法,如自动区分变量推理 (ADVI) 和哈密尔顿蒙特卡洛 (HMC) 在准确性和计算成本方面存在局限性.
- 从可分化的概率密度有效采样是许多科学领域的一个关键挑战.
研究的目的:
- 介绍Pathfinder,一种新的变化方法,用于从可分化的概率密度进行近似采样.
- 为了证明Pathfinder在近似目标分布和生成准确样本方面的有效性.
- 为了突出Pathfinder在现有采样技术上的计算优势.
主要方法:
- 探路器使用准牛顿优化路径来找到对目标密度的正常近似值.
- 通过优化器提供的反向赫斯信息来估计局部共变性.
- 该方法选择了目标分布中估计的Kullback-Leibler (KL) 偏差最小的近似值.
主要成果:
- 路径探测器的近似引力优于ADVI,可与短动态HMC链相比,以1-瓦瑟斯坦距离测量.
- 比ADVI和HMC,Pathfinder需要的日志密度和梯度评估要少一到两个数量级.
- 使用Pathfinder进行重采样进一步提高了样本的多样性和稳定性,减少了1-Wasserstein距离.
结论:
- 路径探测器提供了一个计算效率高,准确的替代方案,用于从概率密度进行近似采样.
- 该方法的并行性提供了显著的速度优势,特别是在多核系统上.
- 对于需要快速可靠的近似贝叶斯推理的应用程序,Pathfinder显示出有前景.
相关概念视频
Estimation of the Physical Quantities
8.5K
On many occasions, physicists, other scientists, and engineers need to make estimates of a particular quantity. These are sometimes referred to as guesstimates, order-of-magnitude approximations, back-of-the-envelope calculations, or Fermi calculations. The physicist Enrico Fermi was famous for his ability to estimate various kinds of data with surprising precision. Estimating does not mean guessing a number or a formula at random. Instead, estimation means using prior experience and sound...
8.5K
One-Compartment Open Model: Wagner-Nelson and Loo Riegelman Method for ka Estimation
1.4K
This lesson introduces two critical methods in pharmacokinetics, the Wagner-Nelson and Loo-Riegelman methods, used for estimating the absorption rate constant (ka) for drugs administered via non-intravenous routes. The Wagner-Nelson method relates ka to the plasma concentration derived from the slope of a semilog percent unabsorbed time plot. However, it is limited to drugs with one-compartment kinetics and can be impacted by factors like gastrointestinal motility or enzymatic degradation.
On...
On...
1.4K
Bernoulli's Equation: Problem Solving
2.0K
A Venturi meter is essential for measuring fluid flow rates in pipelines. It utilizes the relationship between fluid velocity and pressure described by Bernoulli's equation. When installed in a sewage system, the Venturi meter accurately determines the wastewater flow rate by measuring pressure differences.
The first step is to compute the cross-sectional areas of the pipe and the Venturi throat to analyze the pressure difference indicated by the pressure gauge. Next, the continuity equation is...
The first step is to compute the cross-sectional areas of the pipe and the Venturi throat to analyze the pressure difference indicated by the pressure gauge. Next, the continuity equation is...
2.0K
Implicit Differentiation
99
In classical mechanics, motion is often described through relationships between spatial coordinates and time. A car moving along a straight highway with constant acceleration serves as a simple case where velocity is an explicit function of time. This scenario results in a linear equation, enabling straightforward analysis using basic differentiation techniques.In contrast, a satellite in circular orbit follows a path defined by an implicit function. The position of the satellite is constrained...
99
Newton’s Method
111
Newton’s Method is a powerful iterative technique for approximating the roots of real-valued, differentiable functions, particularly when analytical solutions are impractical. This approach is widely used in scientific computing, engineering, and finance, where equations may be too complex for traditional algebraic methods to handle. The method relies on an iterative process that refines an initial estimate using the function’s derivative to approach the true solution progressively.
111
Quadratic Models
283
Quadratic models are mathematical representations used to describe relationships in which the rate of change changes at a constant rate. These models appear in a wide variety of natural and engineered systems, especially those involving motion, forces, and optimization. One common application is analyzing the vertical motion of objects influenced by gravity, such as a ball thrown into the air.In such scenarios, the object's height changes over time in a curved pattern, rising to a maximum point...
283

