Error: Undefined operator '-' for input arguments of type 'cell'.

Hello Matlab experts,

I am trying to subtract 6 secs off of the onset times that I have extracted from an excel file. I now have a series of vectors with the onset times (just a column of numbers) saved in .mat files. I am running into an Error: Undefined operator '-' for input arguments of type 'cell'. I just used the following code:

neutral_cue_onset_time_adjusted=neutral_cue_onset_time-6;
save ('neutral_cue_onset_time_adjusted.mat', 'neutral_cue_onset_time_adjusted');

The previous code I used to find and extract onset times was:

[num,txt,raw] = xlsread ('Placebo_MID_Reward_PLAEGO002_session1_Neutral.xlsx');

% Extract all cue-type onset times

cue_type=raw(:,7);
cue_block_onset=raw(:,9);

neutral_index=find(strcmp(cue_type(:),'neutral'));

neutral_cue_onset_time=cue_block_onset(neutral_index);

save ('neutral_cue_onset_time.mat', 'neutral_cue_onset_time');

I would appreciate any guidance!

Emily

Answer 1

[Alexandra Harkai]

If you want to preserve the shape of your cell array neural_cue_onset_time, you can convert the cells to the underlying data type, subtract 6, then back to the proper shape of cell array:

 neutral_cue_onset_time_adjusted = mat2cell(cell2mat(neutral_cue_onset_time)-6, [dim1, dim2])

Answer 2

[Greg Heath]

 Cut and paste into the command line

 a = 10, b=5
A = num2cell(a)
B = num2cell(b) 
c = b-a
C = gsubtract(B,A)
C = B-A

Hope this helps.

Thank you for formally accepting my answer

Greg