xenial (1) mlpack_sparse_coding.1.gz
NAME
mlpack_sparse_coding - sparse coding
SYNOPSIS
mlpack_sparse_coding [-h] [-v] [-k int] [-c string] [-d string] [-i string] [-m string] [-l double] [-L double] [-n int] [-w double] [-N] [-o double] [-M string] [-s int] [-T string] [-t string] -V
DESCRIPTION
An implementation of Sparse Coding with Dictionary Learning, which achieves sparsity via an l1-norm
regularizer on the codes (LASSO) or an (l1+l2)-norm regularizer on the codes (the Elastic Net). Given a
dense data matrix X with n points and d dimensions, sparse coding seeks to find a dense dictionary matrix
D with k atoms in d dimensions, and a sparse coding matrix Z with n points in k dimensions.
The original data matrix X can then be reconstructed as D * Z. Therefore, this program finds a
representation of each point in X as a sparse linear combination of atoms in the dictionary D.
The sparse coding is found with an algorithm which alternates between a dictionary step, which updates
the dictionary D, and a sparse coding step, which updates the sparse coding matrix.
Once a dictionary D is found, the sparse coding model may be used to encode other matrices, and saved for
future usage.
To run this program, either an input matrix or an already-saved sparse coding model must be specified. An
input matrix may be specified with the --training_file (-t) option, along with the number of atoms in the
dictionary (--atoms, or -k). It is also possible to specify an initial dictionary for the optimization,
with the --initial_dictionary (-i) option. An input model may be specified with the --input_model_file
(-m) option. There are also other training options available.
As an example, to build a sparse coding model on the dataset in data.csv using 200 atoms and an
l1-regularization parameter of 0.1, saving the model into model.xml, use
$ sparse_coding -t data.csv -k 200 -l 0.1 -M model.xml
Then, this model could be used to encode a new matrix, otherdata.csv, and save the output codes to
codes.csv:
$ sparse_coding -m model.xml -T otherdata.csv -c codes.csv
OPTIONS
--atoms (-k) [int]
Number of atoms in the dictionary. Default value 0.
--codes_file (-c) [string]
Filename to save the output sparse codes to. Default value ''. --dictionary_file (-d) [string]
Filename to save the output dictionary to. Default value ''.
--help (-h)
Default help info.
--info [string]
Get help on a specific module or option. Default value ''. --initial_dictionary (-i) [string]
Filename for optional initial dictionary. Default value ''. --input_model_file (-m) [string]
File containing input sparse coding model. Default value ''.
--lambda1 (-l) [double]
Sparse coding l1-norm regularization parameter. Default value 0.
--lambda2 (-L) [double]
Sparse coding l2-norm regularization parameter. Default value 0.
--max_iterations (-n) [int]
Maximum number of iterations for sparse coding (0 indicates no limit). Default value 0.
--newton_tolerance (-w) [double] Tolerance for convergence of Newton method. Default value 1e-06.
--normalize (-N)
If set, the input data matrix will be normalized before coding. --objective_tolerance (-o)
[double] Tolerance for convergence of the objective function. Default value 0.01.
--output_model_file (-M) [string] File to save trained sparse coding model to. Default value ''.
--seed (-s) [int]
Random seed. If 0, 'std::time(NULL)' is used. Default value 0.
--test_file (-T) [string]
File containing data matrix to be encoded by trained model. Default value ''. --training_file
(-t) [string] Filename of the training data (X). Default value ''.
--verbose (-v)
Display informational messages and the full list of parameters and timers at the end of execution.
--version (-V)
Display the version of mlpack.
ADDITIONAL INFORMATION
ADDITIONAL INFORMATION
For further information, including relevant papers, citations, and theory, For further information,
including relevant papers, citations, and theory, consult the documentation found at
http://www.mlpack.org or included with your consult the documentation found at http://www.mlpack.org or
included with your DISTRIBUTION OF MLPACK. DISTRIBUTION OF MLPACK.
mlpack_sparse_coding(1)