1mlpack_gmm_train(1)         General Commands Manual        mlpack_gmm_train(1)
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NAME

6       mlpack_gmm_train - gaussian mixture model (gmm) training
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SYNOPSIS

9        mlpack_gmm_train [-h] [-v]
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DESCRIPTION

12       This  program  takes  a parametric estimate of a Gaussian mixture model
13       (GMM) using the EM algorithm to find the maximum  likelihood  estimate.
14       The  model  may  be saved to file, which will contain information about
15       each Gaussian.
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17       If GMM training fails with an error indicating that a covariance matrix
18       could  not  be inverted, make sure that the --no_force_positive flag is
19       not specified.  Alternately, adding a small amount  of  Gaussian  noise
20       (using  the  --noise  parameter) to the entire dataset may help prevent
21       Gaussians with zero variance in a particular dimension, which  is  usu‐
22       ally the cause of non-invertible covariance matrices.
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24       The  'no_force_positive' flag, if set, will avoid the checks after each
25       iteration of the EM algorithm which ensure that the covariance matrices
26       are  positive  definite.  Specifying the flag can cause faster runtime,
27       but may also cause non-positive  definite  covariance  matrices,  which
28       will cause the program to crash.
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30       Optionally,  multiple trials may be performed, by specifying the --tri‐
31       als option. The model with greatest log-likelihood will be taken.
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REQUIRED INPUT OPTIONS

34       --gaussians (-g) [int]
35              Number of Gaussians in the GMM.
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37       --input_file (-i) [string]
38              File containing the data on which the model will be fit.
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OPTIONAL INPUT OPTIONS

41       --help (-h)
42              Default help info.
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44       --info [string]
45              Get help on a specific module  or  option.   Default  value  ''.
46              --input_model_file  (-m)  [string] File containing initial input
47              GMM model.  Default value ''.
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49       --max_iterations (-n) [int]
50              Maximum number of iterations of EM algorithm (passing 0 will run
51              until convergence). Default value 250.
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53       --no_force_positive (-P)
54              Do not force the covariance matrices to be positive definite.
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56       --noise (-N) [double]
57              Variance  of  zero-mean  Gaussian  noise to add to data. Default
58              value 0.
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60       --percentage (-p) [double]
61              If using --refined_start, specify the percentage of the  dataset
62              used  for each sampling (should be between 0.0 and 1.0). Default
63              value 0.02.
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65       --refined_start (-r)
66              During the initialization, use refined initial positions for  k-
67              means clustering (Bradley and Fayyad, 1998).
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69       --samplings (-S) [int]
70              If  using  --refined_start, specify the number of samplings used
71              for initial points. Default value 100.
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73       --seed (-s) [int]
74              Random seed. If 0, 'std::time(NULL)' is used.  Default value 0.
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76       --tolerance (-T) [double]
77              Tolerance for convergence of EM. Default value 1e-10.
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79       --trials (-t) [int]
80              Number of trials to perform in training GMM.  Default value 1.
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82       --verbose (-v)
83              Display informational messages and the full list  of  parameters
84              and timers at the end of execution.
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86       --version (-V)
87              Display the version of mlpack.
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OPTIONAL OUTPUT OPTIONS

90       --output_model_file  (-M)  [string]  File to save trained GMM model to.
91       Default value ''.
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ADDITIONAL INFORMATION

ADDITIONAL INFORMATION

95       For further information, including relevant papers, citations, and the‐
96       ory, For further information, including relevant papers, citations, and
97       theory, consult the documentation  found  at  http://www.mlpack.org  or
98       included    with    your    consult    the   documentation   found   at
99       http://www.mlpack.org or included with  your  DISTRIBUTION  OF  MLPACK.
100       DISTRIBUTION OF MLPACK.
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