.png){kind=icon}
返回
Technical note: Bit by bit: a practical and general approach for evaluating model computational complexity vs. model performance
.png){kind=icon}
OA
AI
DOI：10.5194/hess-25-1103-2021.png)
.png){kind=icon}
原文求助.png){kind=icon}
分享.png){kind=icon}
收藏
摘要
En 中文
One of the main objectives of the scientific enterprise is the development of well-performing yet parsimonious models for all natural phenomena and systems. In the 21st century, scientists usually represent their models, hypotheses, and experimental observations using digital computers. Measuring performance and parsimony of computer models is therefore a key theoretical and practical challenge for 21st century science. Performance here refers to a model's ability to reduce predictive uncertainty about an object of interest. Parsimony (or complexity) comprises two aspects: descriptive complexity - the size of the model itself which can be measured by the disk space it occupies and computational complexity - the model's effort to provide output. Descriptive complexity is related to inference quality and generality; computational complexity is often a practical and economic concern for limited computing resources. In this context, this paper has two distinct but related goals. The first is to propose a practical method of measuring computational complexity by utility software Strace, which counts the total number of memory visits while running a model on a computer. The second goal is to propose the bit by bit method, which combines measuring computational complexity by Strace and measuring model performance by information loss relative to observations, both in bit. For demonstration, we apply the bit by bit method to watershed models representing a wide diversity of modelling strategies (artificial neural network, auto-regressive, process-based, and others). We demonstrate that computational complexity as measured by Strace is sensitive to all aspects of a model, such as the size of the model itself, the input data it reads, its numerical scheme, and time stepping. We further demonstrate that for each model, the bit counts for computational complexity exceed those for performance by several orders of magnitude and that the differences among the models for both computational complexity and performance can be explained by their setup and are in accordance with expectations. We conclude that measuring computational complexity by Strace is practical, and it is also general in the sense that it can be applied to any model that can be run on a digital computer. We further conclude that the bit by bit approach is general in the sense that it measures two key aspects of a model in the single unit of bit. We suggest that it can be enhanced by additionally measuring a model's descriptive complexity - also in bit.
Keyword:
HYDROLOGIC COMPLEXITY
INFORMATION
CLASSIFICATION
ENTROPY
SCALE
期刊
IF:
5.8
论文数:
6.1K
被引数:
2.8W
机构
引用论文
分享收藏Relation between design floods based on daily maxima and daily means: use of the Peak Over Threshold approach in the Upper Nysa Kłodzka Basin (SW Poland)基于日最大值和日平均值的设计洪水关系：在波兰西南部上诺伊萨-克沃兹卡河流域使用阈值超过法
OAAI
OAAI分享收藏Race, Ethnicity, Income Concentration and 10-Year Change in Urban Greenness in the United StatesOAAI
OAAI分享收藏Does model performance improve with complexity? A case study with three hydrological models.png)
JOURNAL OF HYDROLOGYOAAI
JOURNAL OF HYDROLOGYIF6.3
OAAI分享收藏分享收藏
查看更多内容