How do I average columns in cell array if some cells are empty?

Hi,

I have a cell array called new_mat. I would like to compute the mean of all the values in each column and save the result in a new array called averages. I would then have a numerical array with one row and five columns, so five values in total.

One of my columns however contains an empty cell which I think is causing an error.

I have tried this:

averages = cellfun(@(x) mean(x, 1), new_mat);

But I get this error:

Error using cellfun

Non-scalar in Uniform output, at index 24, output 1.

Set 'UniformOutput' to false.

What am I doing wrong?

Answer 1

[Arif Hoq]

you are asking the same question several times. your cell array "new_mat". giving an answer to your previous question:

https://www.mathworks.com/matlabcentral/answers/1876022-how-do-i-convert-a-cell-array-with-multiple-values-per-cell-into-a-numerical-array-with-multiple-row?s_tid=srchtitle

a=load("split_newdata_mean.mat");
b=a.split_newdata_mean;
b{1,4}=[b{1,4};NaN]; % making equal dimension in the 4th column
c=[b{:}];
new_mat=c';
averages=mean(new_mat)

averages = 1×5

24.4539 30.7694 29.0602 12.3292 NaN

[Arif Hoq]

the average of the 5th column is NaN. If you want it as a numerical then add 0 or any value in the 4th column of the cell array.

a=load("split_newdata_mean.mat");
b=a.split_newdata_mean;
b{1,4}=[b{1,4};0]; % making equal dimension in the 4th column
c=[b{:}];
new_mat=c';
averages=mean(new_mat)

averages = 1×5

24.4539 30.7694 29.0602 12.3292 5.0537

Answer 2

[Voss]

load new_mat
new_mat % notice the cell in the 4th row, 5th column contains an empty array

new_mat = 5×5 cell array
    {[ 2.9473]}    {[ 0.7736]}    {[24.7335]}    {[-32.1028]}    {[  5.4609]}
    {[ 7.9357]}    {[15.6115]}    {[28.3915]}    {[ 51.8624]}    {[       1]}
    {[38.3376]}    {[62.5463]}    {[35.4955]}    {[ 17.6059]}    {[ 35.9168]}
    {[15.0732]}    {[24.9668]}    {[ 3.2505]}    {[-21.6557]}    {0×0 double}
    {[57.9756]}    {[49.9486]}    {[53.4301]}    {[ 45.9361]}    {[-17.1092]}

n_col = size(new_mat,2);
averages = zeros(1,n_col);
for ii = 1:n_col
    averages(ii) = mean([new_mat{:,ii}]);
end

disp(averages);

   24.4539   30.7694   29.0602   12.3292    6.3171

For some explanation: https://www.mathworks.com/matlabcentral/answers/1876727-how-do-i-average-all-the-values-for-each-column-in-a-cell-array#answer_1126617