Find time points that signal changes to the given multi channel bit pattern
ix = vb_multi_bit_start(y,status)
ix = vb_multi_bit_start(y,status,t_stay)
y(n,t) : event signal for n-th ch at time 't' [Nch x T]
status : multi channel bit pattern [Nch x 1]
t_stay : minimum length to stay the specified value [default = 10]
'y' should be stay at the value 'status' for more than t_stay
ix : index corresponding to the start point
'y' changes to 'status' from other value
2012-1-4 Masa-aki Sato
Copyright (C) 2011, ATR All Rights Reserved.
License : New BSD License(see VBMEG_LICENSE.txt)0001 function ix = vb_multi_bit_start(y,status,t_stay) 0002 % Find time points that signal changes to the given multi channel bit pattern 0003 % ix = vb_multi_bit_start(y,status) 0004 % ix = vb_multi_bit_start(y,status,t_stay) 0005 % y(n,t) : event signal for n-th ch at time 't' [Nch x T] 0006 % status : multi channel bit pattern [Nch x 1] 0007 % t_stay : minimum length to stay the specified value [default = 10] 0008 % 'y' should be stay at the value 'status' for more than t_stay 0009 % 0010 % ix : index corresponding to the start point 0011 % 'y' changes to 'status' from other value 0012 % 0013 % 2012-1-4 Masa-aki Sato 0014 % 0015 % Copyright (C) 2011, ATR All Rights Reserved. 0016 % License : New BSD License(see VBMEG_LICENSE.txt) 0017 0018 if nargin < 3, t_stay = 10; end; 0019 0020 [N,T] = size(y); 0021 0022 flg = ones(1,T-t_stay); 0023 tt = 1:T-t_stay; 0024 0025 % 'y' is not 'status' value beforehand 0026 for n=1:N 0027 flg = flg .* (y(n,tt ) == status(n)); 0028 end 0029 0030 flg = (flg ~= 1); 0031 0032 % 'y' should be stay at the value 'status' for more than t_stay 0033 for n=1:N 0034 for t=1:t_stay 0035 flg = flg .* (y(n,tt + t) == status(n)); 0036 end 0037 end 0038 0039 ix = find(flg == 1); 0040 0041 return