Error using reshape function when trying to split columns into equally sized columns in new cell array

Hi,

I have a cell array (participants) with 19 cells (one cell for each participant). Within each cell there is a matrix with 21 columns (21 data points for each participant). I want to split each of the 21 columns into a list of 512 element long columns. This way each of the 21 original colums is cut into smaller columns which are then saved in a new matrix within a new cell array.

Hence each particpant has a cell array where each cell represents one of the original 21 columns. In each cell there is a matrix with 512 long columns that together make up the entirety of the original colum.

For this I have the following code:

for j = 1:numel(participants)
    N = block_size*ceil(numel(participants{j},1)/block_size);
    participants{j,1}(end+1:N,:) = NaN;
    for k = 1:1:num_columns
        p_windows{j,k} = reshape(participants{j,1}(:,k),block_size,[]);
    end
end

The idea is to fill all of the uneven columns with NaNs however when running this code I get the following error:

Error using reshape

Product of known dimensions, 512, not divisible into total number of elements, 23925.

Can anyone help? It seems as though the columns are not filled with NaNs afterall? Thanks!

[Image Analyst]

Make it easy for us to help you: attach participants in a .mat file

save('answers.mat', 'participants');

after reading this:

TUTORIAL: How to ask a question (on Answers) and get a fast answer

In the meantime, tell us how you plan on splitting up the column into groups of 512 rows each when it's not an integer multiple of 512:

>> 23925/512

ans =

46.728515625

It needs to be either 46 or 47. Why is it not?

[lil brain]

I am planning on first filling each of the columns that arent exactly 512 in size with NaNs.

The participants file is attached. Thank you!

Answer 1

[Voss]

The N's are not being calculated correctly, because this line is incorrect:

N = block_size*ceil(numel(participants{j},1)/block_size);

It should be:

N = block_size*ceil(size(participants{j},1)/block_size);

[lil brain]

Wow, thanks it works flawlessly now! Benjamin comes throught to save the day! Loving this community :)

[Voss]

Excellent!