Histogram from Scientific Research

Histogram of $\rho _{i}$’s obtained from the 10k samples (test set). The vectorized gray-scale images, $\mathbf {x}_{i}$, in the MNIST dataset are already sparse in the spatial domain (in canonical basis, i.e., $\Phi =I$) with $\| \mathbf {x}_{i} \| \leq k_{i}$.

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