We present a method for estimating the maximal symmetry of a regression function. Knowledge of such a symmetry can be used to significantly improve modelling by removing the modes of variation resulting from the symmetries. Symmetry estimation is carried out using hypothesis testing for invariance strategically over the subgroup lattice of a search group G acting on the feature space. We show that the estimation of the unique maximal invariant subgroup of G can be achieved by testing on only a finite portion of the subgroup lattice when G_max is a compact subgroup of G, even for infinite search groups and lattices (such as for the 3D rotation group SO(3)). We then show that the estimation is consistent when G is finite. We demonstrate the performance of this estimator in low dimensional simulations, on a synthetic image classification on MNIST data, and apply the methods to an application using satellite measurements of the earth's magnetic field.
翻译:摘要:我们提出了一种通过子群格来估计回归函数最大对称性的方法。这样的对称性的知识可以通过消除对称性导致的变化模式来显著提高建模效果。对称性的估计是通过对作用于特征空间的搜索组G的子群格进行不变假设检验来实现的。我们证明了当G_max是G的紧致子群时,甚至对于无限的搜索组和格子(例如3D旋转群SO(3)),仅在子群格的有限部分上进行测试就可以实现G的唯一最大不变子群的估计。然后我们证明了当G是有限的时,估计值是一致的。我们展示了这个估计器在低维模拟、基于MNIST数据的合成图像分类以及应用卫星测量地球磁场的应用中的性能。