# Extracting the same column in a cell array for anova

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Charms on 24 Oct 2019
Commented: Adam Danz on 24 Oct 2019
Hi, I currently have a 1 x 8 cell (attached) and would like to extract the same column in every double and run an anova1 on them - eg 1st column in the 41 x 6 double, 1st column in the 80 x 6 double .... (total of 8 groups). May I know how I may do so?
Thank you, any help is much appreciated.

Adam Danz on 24 Oct 2019
Edited: Adam Danz on 24 Oct 2019
'c' is your cell array. The first line extracts the first column from each of the elements of c and stores their values in a single column vector. The second line creates a grouping variable of the same length indicating which of the cell groups the data are from. See anova1 for more options on the 3rd line.
y = cell2mat(cellfun(@(x)x(:,1),c,'UniformOutput',false).');
group = cell2mat(cellfun(@(x,i)ones(size(x,1),1).*i,c,num2cell(1:numel(c)),'UniformOutput',false).');
p = anova1(y,group)

Charms on 24 Oct 2019
this works! Is there a line I can add to the code so it does the same for the 2nd to 6th columns of every double?
Adam Danz on 24 Oct 2019
You'd just need to change the first line. Set col to any column number.
col = 1;
y = cell2mat(cellfun(@(x)x(:,col),c,'UniformOutput',false).');
% ^^^
Walter has a similar variable in his answer, too.

Walter Roberson on 24 Oct 2019
col_to_extract = 1;
the_columns_as_cells = cellfun(@(C) C(:,col_to_extract), YourCellArray, 'uniform', 0);
You cannot, however, combine these into a single something-by-8 numeric array, as the cells have different numbers of rows.