brede_mat_nmf - Non-negative matrix factorization
[W, H] = brede_mat_nmf(M, varargin)
[W, L, H] = brede_mat_nmf(M, varargin)
Input: M 'Mat' structure
Property: Components [ {4} | Positive integer | Auto ]
Number of components
Cost [ {Euclidean} | Divergence ] Cost
function
Info Amount of information. A value over
5 gives a plot of cost function
evolution
IterationProbe [ {250} | Positive integer ]
Iterations before the cost function is
evaluated
MaxIterations [ {50000} | Positive integer ] Number of
iterations of the algorithm
Runs [ {1} | positive integer ] Number of
restarts
Seed [ {[]} | real ] Seed for random
generator
ToleranceZeroWH [ {10^20 * realmin} | real | [] ]
Value specifying numerically zero
element in W and H
Output: W 'Max' structure
H 'Mat' structure
L 'Mat' structure
Non-negative matrix factorization
W * H = nmf(M)
If there are 3 output arguments the left and right matrices
will be unitary matrices while the middle matrix will contain
"eigenvalues":
W * L * H = nmf(M)
The rank will of WH will typically be lower than the rank of M
so that there is a residual: WH = M + U.
'Components' specifies the number of columns of W and the
number of rows of H, ie, the rank of the decomposition.
'Cost' specifies the cost-function that is optimized. ...
'Euclidean' is the square error (the Frobenius norm of the
residual), while 'Divergence' is a Kullback-Leibler type
(information theoretic cost).
'MaxIterations' is the maximum number of iterations. The
algorithm might stop before if one of the other stop criteria
are met.
The function uses brede_nmf_est to do the actual
update/estimation of the NMF model. See this function for more
information.
Example:
f = fullfile(fileparts(which('brede')), 'xml', 'wobibs.xml');
B = brede_read_xml(f, 'output', 'collapsesecond');
M = brede_bib_bib2mat(B, 'type', 'abstract');
M = brede_mat_elimsingle(M)
M = brede_mat_elimstop(M, 'filename', 'stop_english1.txt')
M = brede_mat_elimstop(M, 'filename', 'stop_medline.txt')
M = brede_mat_elimstop(M, 'filename', 'stop_lobaranatomy.txt')
M = brede_mat_elimstop(M, 'filename', 'stop_meshcommon.txt')
M = brede_mat_elimstop(M, 'filename', 'stop_pubmed_neg1.txt')
[W, H] = brede_mat_nmf(M, 'Info', 3)
See also BREDE, BREDE_MAT, BREDE_NMF_EST, BREDE_MAT_ICA,
BREDE_MAT_KMC, BREDE_MAT_SVD.
$Id: brede_mat_nmf.m,v 1.18 2008/02/28 22:57:24 fn Exp $