fmatrix.m

使用变分EM方法实现的LDA文本模型 输入为文本即可 分解实现

function m = fmatrix(file,offset)
% m = fmatrix(file,[offset])
% constructs a cell array of struct of (id, cnt) array.
% file   : file of feature data
% offset : offset of initial feature id (specify 1 if you use zero-origin id)
% m      : cell array of data, each cell d is a struct of {d.id, d.cnt},
%          each of which is an array of ids and corresponding counts.
%          e.g. d.id(1) = 5, d.cnt(1) = 2
%               d.id(2) = 1, d.cnt(2) = 10 ..
% $Id: fmatrix.m,v 1.6 2004/10/26 02:23:37 dmochiha Exp $
if nargin < 2
  offset = 0;
end
% open file
fid = fopen(file);
if (fid == -1)
  error(sprintf('fmatrix: can''t open %s.',file));
end
m = {};
j = 0;
% read file
while ~feof(fid)
  l = fgetl(fid);
  f = sscanf(l,'%d:%g',Inf);
  n = length(f) / 2;
  assert(isint(n));
  d.id  = zeros(1,n);
  d.cnt = zeros(1,n);
  for i = 1:n
    d.id(i)  = f(2*i-1) + offset;
    d.cnt(i) = f(2*i);
  end
  j = j + 1;
  m{j} = d;
end
% close file
fclose(fid);