www.pudn.com > HMM1.zip > fit_partitioned_model.m

function [model, partition_size] = fit_partitioned_model(... 
    inputs, outputs, selectors, sel_sizes, min_size, partition_names, fn_name, varargin) 
%function [models, partition_sizes] = fit_partitioned_model(... 
%    inputs, outputs, selectors, sel_sizes, min_size, partition_names, fn_name, varargin) 
% 
% Fit models to different subsets (columns)  of the input/output data,  
% as chosen by the selectors matrix. If there is only output data, set input=[]. 
% If there is less than min_size data in partition i,  
% we set model{i} = [] 
% 
% Example: 
% selectors = [1 2 1 1 1 
%              1 2 2 1 2] 
% sel_sizes = [2 2] so there are 4 models: (1,1), (2,1), (1,2), (2,2) 
% We fit model{1} to data from columns 1,4 
% We fit model{2} to no data 
% We fit model{3} to data from column 3,5 
% We fit model{4} to data from column 2 (assuming min_size <= 1) 
% 
% For each partition, we call the specified function with the specified arguments 
% as follows: 
%  model{i}  = fn(input(:,cols{i}), output(:,cols{i}), args) 
% (We omit input if []) 
% partition_size(i) is the amount of data in the i'th partition. 
% 
% Example use: row 1 of selectors is whether an object is present/absent 
% and row 2 is the location. 
% 
% Demo: 
% inputs = 1:5; outputs = 6:10; selectors = as above 
% fn = 'fit_partitioned_model_testfn'; 
% [model, partition_size] = fit_partitioned_model(inputs, outputs, selectors, [2 2], fn) 
% should produce 
% model{1}.input = [1 4], model{1}.output = [6 9] 
% model{2} = [] 
% model{3}.input = [3 5], model{3}.output = [8 10],  
% model{4}.input = [2], model{3}.output = [7],  
% partition_size = [2 0 2 1] 
 
 
sel_ndx = subv2ind(sel_sizes, selectors'); 
Nmodels = prod(sel_sizes); 
model = cell(1, Nmodels); 
partition_size = zeros(1, Nmodels); 
for m=1:Nmodels 
  ndx = find(sel_ndx==m); 
  partition_size(m) = length(ndx); 
  if ~isempty(partition_names) % & (partition_size(m) < min_size) 
    fprintf('partition %s has size %d, min size = %d\n', ... 
	    partition_names{m}, partition_size(m), min_size); 
  end 
  if partition_size(m) >= min_size 
    if isempty(inputs) 
      model{m} = feval(fn_name, outputs(:, ndx), varargin{:}); 
    else 
      model{m} = feval(fn_name, inputs(:,ndx), outputs(:, ndx), varargin{:}); 
    end 
  end 
end