Sparsemax
Sparsemax
**Sparsemax** is a type of activation/output function similar to the traditional [softmax](https://paperswithcode.com/method/softmax), but able to output sparse probabilities. 

$$ \text{sparsemax}\left(z\right) = \arg\_{p∈\Delta^{K−1}}\min||\mathbf{p} - \mathbf{z}||^{2} $$
From Softmax to Sparsemax: A Sparse Model of Attention and Multi-Label Classification
https://paperswithcode.com/paper/from-softmax-to-sparsemax-a-sparse-model-of
From Softmax to Sparsemax: A Sparse Model of Attention and Multi-Label Classification