Questions tagged [sparsity]

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What is the difference between sparse and dense corpra?

I didn't got the meaning or the difference between sparse and dense corpra here in this sentence "the reason is that Skip-gram works better over sparse corpora like Twitter and NIPS, while CBOW ...
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1answer
53 views

Autoencoder train and test accuracy shooting to 99% on few epochs

I am trying to train an autoencoder for dimensionality reduction and hopefully for anomaly detection. My data specifications are as follows. Unlabeled 1 million data points 9 features I am trying to ...
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2answers
289 views

What is the meaning of the sparsity parameter

Sparse methods such as LASSO contain a parameter $\lambda$ which is associated with the minimization of the $l_1$ norm. Higher the value of $\lambda$ ($>0$) means that more coefficients will be ...
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Clustering of sparse matrix with many co-variates

I have a 2M x 2000 sparse matrix where rows represent an item and columns represent dimensions. I want to understand whether there are meaningful clusters in the data and I started to explore the ...
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0answers
154 views

Loss function for Autoencoder of sparse 3D Image

I have 3D structure data of molecules. I represented the atoms as points in a 100*100*100 grid and applied a gaussian blur to counter the sparseness. (nearly all of the grid cells contain zeros) I am ...
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0answers
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If $\ell_0$ regularization can be done via the proximal operator, why are people still using LASSO?

I have just learned that a general framework in constrained optimization is called "proximal gradient optimization". It is interesting that the $\ell_0$ "norm" is also associated with a proximal ...