vb_eeg_get_active_trigger_channel

 extract active trigger channels by reading status channel data
 [usage]
   [ch_list, bit_list] = vb_eeg_get_active_trigger_channel(status_data, bit_len)
 [input]
   status_data : <required> data of status channel [1 x N]
       bit_len : <optional> bit length of data [24]
 [output]
    ch_list : list of active trigger channels
   bit_list : list of bit of selected channel
 [note]
 [history]
   2007-01-04 (Sako) initial version

 Copyright (C) 2011, ATR All Rights Reserved.
 License : New BSD License(see VBMEG_LICENSE.txt)

0001 function [ch_list, bit_list] = ...
0002   vb_eeg_get_active_trigger_channel(status_data, bit_len)
0003 % extract active trigger channels by reading status channel data
0004 % [usage]
0005 %   [ch_list, bit_list] = vb_eeg_get_active_trigger_channel(status_data, bit_len)
0006 % [input]
0007 %   status_data : <required> data of status channel [1 x N]
0008 %       bit_len : <optional> bit length of data [24]
0009 % [output]
0010 %    ch_list : list of active trigger channels
0011 %   bit_list : list of bit of selected channel
0012 % [note]
0013 % [history]
0014 %   2007-01-04 (Sako) initial version
0015 %
0016 % Copyright (C) 2011, ATR All Rights Reserved.
0017 % License : New BSD License(see VBMEG_LICENSE.txt)
0018 
0019 % --- CHECK ARGUMENTS --- %
0020 if ~exist('status_data', 'var'), status_data = []; end;
0021 if ~exist('bit_len', 'var'), bit_len = []; end;
0022 [status_data, bit_len] = inner_check_arguments(status_data, bit_len);
0023 
0024 
0025 % --- MAIN PROCEDURE --------------------------------------------------------- %
0026 %
0027 ch_list = [];
0028 
0029 data_len = size(status_data,2);
0030 BIT_LEN = bit_len;
0031 
0032 result_box = zeros(1,data_len);
0033 all_bit_list = zeros(1,data_len);
0034 bit_list = zeros(1,data_len);
0035 
0036 % VERBOSE = 0;
0037 VERBOSE = 1;
0038 if VERBOSE, fprintf('  >>> read status bit (%d) ', BIT_LEN); end;
0039 
0040 list_cnt = 0;
0041 
0042 for nbit = 1:BIT_LEN
0043   check_bit = 2 ^ (nbit-1);
0044   result_box = vb_bitand_ex(status_data(:,:),check_bit,BIT_LEN);
0045   all_bit_list = (result_box == check_bit);
0046 
0047   % if all bit is high, it means not to be connected (maybe)
0048   if any(all_bit_list) && ~all(all_bit_list)
0049     ch_list = [ch_list, nbit];
0050     bit_list(size(ch_list,2),:) = all_bit_list;
0051   end
0052   if VERBOSE, fprintf('.'); end;
0053 end
0054 if VERBOSE, fprintf(' done\n'); end;
0055 %
0056 % --- END OF MAIN PROCEDURE -------------------------------------------------- %
0057 
0058 % --- INNER FUNCTIONS -------------------------------------------------------- %
0059 %
0060 % --- inner_check_arguments()
0061 %
0062 function [status_data, bit_len] = inner_check_arguments(status_data, bit_len)
0063 if isempty(status_data)
0064   error('status_data is a required parameter');
0065 end
0066 
0067 if isempty(bit_len), bit_len = 24; end;
0068 %
0069 % --- end of inner_check_arguments()
0070 
0071 %%% END OF FILE %%%