Delete rows from a cell array based on key words

Hello,

I have currently created a cell array that takes the following form:

'6440.016'	'hold'
'7378.016'	'max-pressure-evac 60.0'
'8372.016'	'max-pressure-evac 60.0'
'9365.016'	'max-pressure-evac 60.0'
'10357.016'	'max-pressure-evac 60.0'
'11338.016'	'max-pressure-evac 60.0'
'12298.016'	'max-pressure-evac 60.0'
'13259.016'	'max-pressure-evac 60.0'
'14221.016'	'max-pressure-evac 60.0'
'15184.016'	'max-pressure-evac 60.0'
'16149.016'	'max-pressure-evac 60.0'
'17115.016'	'max-pressure-evac 60.0'
'18082.016'	'max-pressure-evac 60.0'
'19050.016'	'max-pressure-evac 60.0'
'19424.016'	'hold-end'
'19553.016'	'hold'
'20272.016'	'max-pressure-evac 60.0'
'21109.016'	'max-pressure-evac 60.0'
'21919.016'	'hold-end'
'22048.016'	'hold'
'22651.016'	'max-pressure-evac 60.0'
'23374.016'	'max-pressure-evac 60.0'
'23489.016'	'hold-end'
'23619.016'	'hold'
'24131.016'	'max-pressure-evac 60.0'
'24762.016'	'max-pressure-evac 60.0'
'25060.016'	'hold-end'
'25190.016'	'hold'
'25640.016'	'max-pressure-evac 60.0'
'26212.016'	'max-pressure-evac 60.0'
'26631.016'	'hold-end'

If there are consecutive rows that say 'max-pressure-evac 60.0', I wish to only keep the final 'max-pressure-evac 60.0' and delete the ones above it. To clarify, here I have 5 different occaisons where 'max-pressure-evac 60.0' is repeated. Instead of having 21 'max-pressure-evac 60.0' rows I only want 5 which correspond to the time stamps of 19050, 21109, 23374, 24762, and 26212. I'm unable to wrap my mind around accomplishing this and any help would be greatly appreciated.

Answer 1

[Voss]

data = { ...
    '6440.016'	'hold'; ...
    '7378.016'	'max-pressure-evac 60.0'; ...
    '8372.016'	'max-pressure-evac 60.0'; ...
    '9365.016'	'max-pressure-evac 60.0'; ...
    '10357.016'	'max-pressure-evac 60.0'; ...
    '11338.016'	'max-pressure-evac 60.0'; ...
    '12298.016'	'max-pressure-evac 60.0'; ...
    '13259.016'	'max-pressure-evac 60.0'; ...
    '14221.016'	'max-pressure-evac 60.0'; ...
    '15184.016'	'max-pressure-evac 60.0'; ...
    '16149.016'	'max-pressure-evac 60.0'; ...
    '17115.016'	'max-pressure-evac 60.0'; ...
    '18082.016'	'max-pressure-evac 60.0'; ...
    '19050.016'	'max-pressure-evac 60.0'; ...
    '19424.016'	'hold-end'; ...
    '19553.016'	'hold'; ...
    '20272.016'	'max-pressure-evac 60.0'; ...
    '21109.016'	'max-pressure-evac 60.0'; ...
    '21919.016'	'hold-end'; ...
    '22048.016'	'hold'; ...
    '22651.016'	'max-pressure-evac 60.0'; ...
    '23374.016'	'max-pressure-evac 60.0'; ...
    '23489.016'	'hold-end'; ...
    '23619.016'	'hold'; ...
    '24131.016'	'max-pressure-evac 60.0'; ...
    '24762.016'	'max-pressure-evac 60.0'; ...
    '25060.016'	'hold-end'; ...
    '25190.016'	'hold'; ...
    '25640.016'	'max-pressure-evac 60.0'; ...
    '26212.016'	'max-pressure-evac 60.0'; ...
    '26631.016'	'hold-end'; ...
    };

% gonna calculate the indices of the rows we want to keep.
% first make a vector of indices of all rows:
all_idx = 1:size(data,1);
% then find whether or not each row has 'max-pressure-evac 60.0':
idx = strcmp(data(:,2),'max-pressure-evac 60.0');
% now, keep those rows that do not say 'max-pressure-evac 60.0'
% (all_idx(~idx)), along with those rows that *do* say 
% 'max-pressure-evac 60.0', if the next row says something else 
% (or if it's the last row of data - there is no next row):
keep_idx = [all_idx(~idx) strfind([idx.' false],[true false])];
% grab those rows of data, in the right order:
new_data = data(sort(keep_idx),:);
disp(new_data);

    {'6440.016' }    {'hold'                  }
    {'19050.016'}    {'max-pressure-evac 60.0'}
    {'19424.016'}    {'hold-end'              }
    {'19553.016'}    {'hold'                  }
    {'21109.016'}    {'max-pressure-evac 60.0'}
    {'21919.016'}    {'hold-end'              }
    {'22048.016'}    {'hold'                  }
    {'23374.016'}    {'max-pressure-evac 60.0'}
    {'23489.016'}    {'hold-end'              }
    {'23619.016'}    {'hold'                  }
    {'24762.016'}    {'max-pressure-evac 60.0'}
    {'25060.016'}    {'hold-end'              }
    {'25190.016'}    {'hold'                  }
    {'26212.016'}    {'max-pressure-evac 60.0'}
    {'26631.016'}    {'hold-end'              }

Showing the relevant intermediate variables' values so you can get a feel for how this works:

disp(idx.')

   0   1   1   1   1   1   1   1   1   1   1   1   1   1   0   0   1   1   0   0   1   1   0   0   1   1   0   0   1   1   0

disp(strfind([idx.' false],[true false]))

    14    18    22    26    30

[Justin Rosenthal]

Thank you so much for your help this works perfectly!