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