稀疏编码自编码表达
From Ufldl
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Formally, in sparse coding, we have some data x we would like to learn features on. In particular, we would like to learn s, a set of sparse features useful for representing the data, and A, a basis for transforming the features from the feature space to the data space. Our objective function is hence: | Formally, in sparse coding, we have some data x we would like to learn features on. In particular, we would like to learn s, a set of sparse features useful for representing the data, and A, a basis for transforming the features from the feature space to the data space. Our objective function is hence: | ||
- | :<math> | + | :<math>J(A, s) = \lVert As - x \rVert_2^2 + \lambda \lVert s \rVert_1</math> |