psom_set_defaults.m

%
% _________________________________________________________________________
% SUMMARY PSOM_SET_DEFAULTS
%
% Upload fields of a structure as variables of the workspace, with default
% values.
%
% SYNTAX:
% PSOM_SET_DEFAULTS
%
% This is a script !! Values of the workspace which calls the script will
% be affected.
%
% _________________________________________________________________________
% INPUTS : 
% There is no input per say, as this is a script and not a function.
% The following variables still need to exist in the workspace before 
% calling the script : 
%
% GB_NAME_STRUCTURE   
%       (string) the name of the structure to test.
%
% GB_LIST_FIELDS      
%       (cell of strings) names of fields.
%
% GB_LIST_DEFAULTS    
%       (cell) the default values. A Nan will produce an error message and 
%       exit if no value is defined in the field.
%
% _________________________________________________________________________
% OUTPUTS :
%
% All fields listed in GB_LIST_FIELDS are checked in the structure 
% GB_NAME_STRUCTURE, and default values are applied if they don't exist. 
% In addition, the listed fields are uploaded as variables. A warning is 
% issued if unlisted fields are found in GB_NAME_STRUCTURE. Values of the 
% structure are updated.
%
% COMMENTS:
%
% Copyright (c) Pierre Bellec, Montreal Neurological Institute, 2008.
% Maintainer : pbellec@bic.mni.mcgill.ca
% See licensing information in the code.

% Permission is hereby granted, free of charge, to any person obtaining a copy
% of this software and associated documentation files (the "Software"), to deal
% in the Software without restriction, including without limitation the rights
% to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
% copies of the Software, and to permit persons to whom the Software is
% furnished to do so, subject to the following conditions:
%
% The above copyright notice and this permission notice shall be included in
% all copies or substantial portions of the Software.
%
% THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
% IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
% FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
% AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
% LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
% OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
% THE SOFTWARE.

%% Test if the structure exist, otherwise initialize an empty one
if exist(gb_name_structure,'var')
    eval(cat(2,'gb_psom_struct = ',gb_name_structure,';'));    
else
    gb_psom_struct = struct([]);
end
   
%% Loop on every field
nb_fields = length(gb_list_fields);
for num_f = 1:nb_fields
    
    field = gb_list_fields{num_f};
    val = gb_list_defaults{num_f};
    flag_field = isfield(gb_psom_struct,field);

    %% If the field does not exist, create it with default value
    if ~flag_field  
        if isnumeric(val)
            if isnan(val)
                error(cat(2,'psom:defaults: Please specify field ',field,' in structure ',gb_name_structure,' !\n'))                
            end
        end        
        gb_psom_struct(1).(field) = val;        
    end    
                    
    % Upload the field as a variable
    eval(cat(2,field,' = gb_psom_struct.',field,';')); % 
end

%% Test if some field were not used, and eventually issue a warning.
gb_list_fields_init = fieldnames(gb_psom_struct);
gb_mask_init = ismember(gb_list_fields_init,gb_list_fields);
if min(gb_mask_init)==0
    gb_fields_warning = [];
    gb_ind_init = find(gb_mask_init==0);
    for num_i = 1:length(gb_ind_init)
        gb_fields_warning = [gb_fields_warning ' ' gb_list_fields_init{gb_ind_init(num_i)}];
    end
    warning(cat(2,'psom:default: The following field(s) were ignored in the structure ',gb_name_structure,' : ',gb_fields_warning));
end

%% Export the structure
eval(cat(2,gb_name_structure,' = gb_psom_struct;'))