One-shot atomic detection

Feature selection in data science involves identifying the most prominent and uncorrelated features in the data, which can be useful for compression and interpretability. If these feature can be easily extracted, then a model can be trained over a reduced set of weights, which leads to more efficient training and possibly more robust classifiers. There are many approaches to feature selection; in this work, we propose screening the "atoms" of a gradient of a loss function taken at a random point. We illustrate this approach on sparse and low-rank optimization problems. Despite the simplicity of the approach, we are often able to select the dominant features easily, and greatly improve the runtime and robustness in training overparametrized models.