A novel dimensionality reduction method based on flow model

Abstract

The sparsity and redundancy of high-dimensional data poses challenges during processing. Dimensionality reduction is a commonly used approach, which helps to reduce data redundancy and noise, lower the complexity of learning algorithms, and improve classification accuracy. Typically, directly determining the intrinsic dimensionality of a dataset is challenging. Many of the present dimensionality reduction techniques suffer from pre-set target dimensions without considering the specific dataset features. To address this problem, a novel dimensionality reduction method based on flow model, which is called adaptive flow encoder (AFE), is proposed in this paper. Initially, the flow model is employed to achieve feature transformation and project the data onto an equip-dimensional feature space. Subsequently, a gating layer is utilized for feature selection. By configuring the gating layer parameters to be learnable, the model gains the ability to adaptively select features. To assess the efficacy of the proposed approach, the model’s ability to preserve data characteristics is first qualitatively evaluated through visual inspection by projecting the data onto a two-dimensional space. Subsequently, five standard datasets are employed and compared against six traditional dimensionality reduction techniques to ascertain the impact on downstream classification tasks under the adaptive learning of intrinsic feature dimensions by the model. Moreover, the impact of key parameters, including the initialization scheme of the gate layer, amplification factor, and dimension factor, on the test results is examined.