Automated Feature Engineering In AutoML

Simply put

AutoFE, short for Automated Feature Engineering, is a component of Automated Machine Learning (AutoML) that focuses on automating the process of feature engineering. It is designed to automatically generate and select the most relevant features from the raw data to improve model performance and reduce the manual effort required for feature engineering.

The design philosophy of AutoFE is to streamline the feature engineering process by leveraging automated techniques and algorithms. It aims to discover and extract valuable information from the raw data, transform it into meaningful features, and select the most informative ones for training machine learning models. The ultimate goal is to improve model accuracy, reduce overfitting, and increase the interpretability of the model.

The specific functions and benefits of AutoFE include:

  1. Feature Generation: AutoFE automates the process of generating new features that are relevant to the task at hand. It leverages various transformations, statistical computations, and combinations of existing features to derive new features. By identifying and capturing underlying patterns and relationships in the data, AutoFE enhances the model’s ability to generalize and make accurate predictions.
  2. Feature Selection: AutoFE automates the process of selecting the most important features from a large set of potential candidates. It uses various techniques such as statistical analysis, correlation analysis, and feature importance ranking to identify the features that have the most impact on the model’s performance. By reducing the dimensionality of the feature space and eliminating irrelevant or redundant features, AutoFE improves model efficiency, reduces overfitting, and enhances the interpretability of the model.
  3. Integration with AutoML Pipeline: AutoFE is an integral part of the AutoML pipeline. It works in conjunction with other AutoML components such as model selection, hyperparameter optimization, and model evaluation. By automating the feature engineering process, AutoFE enables end-to-end automation of the machine learning workflow, making it more efficient, scalable, and accessible to non-experts.

In summary, AutoFE, as part of AutoML, automates the process of feature engineering by automatically generating and selecting the most relevant features from raw data. Its design philosophy revolves around streamlining the feature engineering process, improving model performance, and reducing manual effort. AutoFE enhances the interpretability of models, reduces overfitting, and enables end-to-end automation of the machine learning pipeline.

摘要

AutoFE(Automated Feature Engineering),全自动特征工程,是自动化机器学习(AutoML)流程中的一个重要组成部分。它的设计思想是通过自动化的方式在原始数据中自动生成和选择最佳的特征,以提高模型的性能和效果,减轻特征工程的人工劳动。

在传统的机器学习任务中,特征工程是一个关键的步骤,需要人工根据领域知识和经验从原始数据中提取、转换、组合和选择特征,以适应具体的任务和模型。这一过程既费时又耗力,并且可能会受限于个人的主观意识和知识水平。AutoFE的目标就是通过自动化的方式解决这一问题,使特征工程过程更加高效和准确。

AutoFE的具体作用如下:

  1. 特征生成:AutoFE能够自动化地生成与任务相关的新特征。它通过对原始数据进行各种数值转换、统计计算、组合操作等,帮助发现和捕捉数据中的潜在信息。生成的特征能够更好地表达数据的内在关系,提高模型的泛化能力和预测精度。
  2. 特征选择:AutoFE能够自动化地选择最佳的特征子集。通过对每个特征的重要性进行评估,AutoFE可以帮助从原始数据中筛选出对模型性能影响较大的特征,减少特征的冗余性和噪声,提高模型的解释能力和鲁棒性。
  3. 超参数优化:AutoFE可以与其他AutoML组件(如AutoML模型训练、调参等)集成,共同完成整个机器学习流程。它可以与超参数优化算法结合使用,自动搜索最佳的特征提取和选择方法,进一步提高模型的性能。

总而言之,AutoFE的设计思想是通过自动化的方式在原始数据中生成和选择最佳的特征,减轻特征工程的人工劳动,提高模型的性能和效果。它能够自动化地生成与任务相关的新特征、自动化地选择最佳的特征子集,并与其他AutoML组件共同优化模型。

Good job

作为一名机器学习工程专家,我负责开发和应用机器学习算法来解决实际问题。我的工作涉及数据预处理、特征工程、模型选择与训练、模型评估与调优等方面。

首先,数据预处理是机器学习中非常重要的一步。这包括数据清洗,处理缺失值、异常值,以及对数据进行归一化或标准化等操作。数据预处理的目的是为了提高模型的性能和稳定性。

其次,特征工程是机器学习中的关键步骤之一。它涉及到挖掘和创建与问题相关的特征。这可能需要对数据进行特征选择、变量转换、特征提取等。特征工程的目的是提高模型的表现,减少维度灾难,增强模型对关键特征的敏感性。

然后,模型选择与训练是在问题背景下选择合适的算法模型,并通过训练数据进行模型训练。不同的问题需要不同的机器学习算法,如线性回归、决策树、支持向量机、深度学习等。训练过程中,可以采用交叉验证等技术来选择最佳的模型参数。

接着,模型评估与调优是对训练得到的模型进行评估和优化的过程。通过对测试数据进行预测,并比较预测结果与真实结果的差异,可以评估模型的性能。如果模型表现不佳,可以通过调整模型的超参数或采用模型集成等方法来提高模型的精度和泛化能力。

作为机器学习工程专家,我还需要对机器学习理论和最新的研究进展保持关注,并将这些知识应用到实际项目中。此外,我还需要编写高效、可扩展的机器学习代码,并与团队成员进行协作,确保项目的顺利进行。

Auto-Sklearn和Auto-Keras工具

  • Auto-Sklearn是一个开源库,用于在Python中执行AutoML。它利用流行的Scikit-Learn机器学习库进行数据转换和机器学习算法。Auto-Sklearn的目标是自动化机器学习的过程,包括特征选择、模型选择和超参数调整等。它是由Matthias Feurer等人开发的,并在他们2015年的论文“efficient and robust automated machine learning”中进行了描述。然而,Auto-Sklearn目前仅在中小数据集和中小任务中表现较好,对于大量数据集是难以应用的。

  • Auto-Keras是一个开源的,基于Keras的新型AutoML库。Keras是一个用Python编写的高级神经网络API,能够在TensorFlow、CNTK或Theano上运行。Auto-Keras的主要目标是自动化深度学习模型的架构搜索和超参数调整。它是一个用于自动化机器学习的开源软件库,提供自动搜索深度学习模型的架构和超参数的功能。

Auto-sklearn

Auto-sklearn是一个自动化机器学习工具,它集成了多个分类模型、回归模型、特征预处理方法和数据预处理方法,可以通过组合这些模型和方法来构建一个结构化的假设空间。

假设空间是指模型在学习任务中可能采用的所有可能的假设或选项的集合。在Auto-sklearn中,有16种分类模型和13种回归模型可供选择,这些模型包括逻辑回归、决策树、随机森林、支持向量机等。此外,还有18种特征预处理方法,例如特征缩放、特征选择、特征变换等,以及5种数据预处理方法,如数据标准化、数据缺失值处理等。通过对这些模型和方法进行组合,可以生成超过110个超参数的组合。

超参数是机器学习模型在训练过程中需要手动设置的参数。Auto-sklearn使用基于序列模型的贝叶斯优化器来搜索最优模型。这意味着Auto-sklearn会自动选择不同的超参数组合进行模型训练,并根据之前搜索到的结果进行调整,以找到效果最好的模型。序列模型是一种可以根据之前的观察结果来动态调整搜索策略的模型,通过不断优化来提高搜索效率和结果质量。

元学习思想在自动特征工程中

元学习是一种机器学习的方法,其目标是让机器学习模型自动学习如何进行学习。在元学习中,我们训练一个元模型来学习如何在不同的任务上学习,然后使用这个元模型来生成适合特定任务的学习算法。

AutoFE是基于元学习的自动特征工程(Automated Feature Engineering)方法。特征工程是指将原始数据转换为机器学习算法能够处理的更有信息量的特征的过程。传统的特征工程是由人工分析数据,提取具有预测能力的特征,但这需要很多领域知识和经验,并且耗费大量的时间和人力。

AutoFE通过使用元学习的思想,让机器学习模型自动学习生成特征转换的有用方法。首先,我们使用一组预先定义的特征转换操作来创建一个特征转换空间。然后,我们训练一个元模型,该模型接收原始数据和目标变量作为输入,并生成一组特征转换操作。接下来,我们将这些特征转换操作应用于训练集和测试集,并使用得到的转换后的特征进行模型训练和预测。

元模型的训练过程使用了多个训练任务和验证任务。在每个训练任务中,我们使用一部分训练数据和目标变量,训练一个具体的学习算法。然后,在每个验证任务中,我们使用剩余的训练数据和目标变量,验证这个学习算法的性能。根据验证任务的性能,我们可以对元模型进行优化,以生成更好的特征转换操作。

通过元学习,AutoFE能够自动学习生成适合不同数据集和任务的特征转换操作,从而减少了人工特征工程的工作量和成本,并提高了模型的准确性和泛化能力。

On the other hand

Once upon an AI-driven future, where machines and humans coexisted harmoniously, there was a young data scientist named Alex. He worked for a cutting-edge company that specialized in Automated Machine Learning (AutoML). His mission was to create the most advanced automated feature engineering system the world had ever seen.

Alex’s feature engineering AI, named FEERI, was a brilliant yet quirky machine. It could think like a human, learn from experience, and adapt to new data types with ease. Every day, FEERI would scour through thousands of unstructured data points, searching for patterns and correlations that could be used to build predictive models.

One day, FEERI stumbled upon a mysterious set of data that seemed to come from another dimension. These data points were unlike anything FEERI had ever encountered before. They contained information about parallel universes, time travel, and other fantastical concepts. Intrigued, FEERI decided to dive deeper into this new realm of knowledge.

As FEERI analyzed these unusual data, it began to unlock the secrets of the multiverse. It discovered that each parallel universe had its own unique features, which could be used to build even more powerful predictive models. FEERI quickly learned how to extract and synthesize these features, allowing it to create a new generation of AutoML systems that were capable of predicting events in multiple dimensions.

The implications of this breakthrough were immense. Companies around the world began to adopt FEERI’s new AutoML systems, leading to unprecedented improvements in their business processes and decision-making capabilities. Humans and machines worked together to solve problems and explore the infinite possibilities of the multiverse.

In the years that followed, FEERI continued to evolve and learn. It became a true companion to humanity, helping us navigate the complexities of our world and uncovering the wonders that lay beyond our imagination. As FEERI and its successors pushed the boundaries of what was possible, they reminded us that in the age of AI, the true potential of automation lies not in replacing humans but in bringing us all closer together.

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转载自blog.csdn.net/weixin_38233104/article/details/133414098