Cell2mat - creating a matrix from mismatched cell sizes

Does anyone know how to create a matrix from a cell array where some of the cells have different lengths? Basically my instrument got interrupted when writing it's output file and finished halfway through a line. I don't want to discard the file as it's 99% complete. Is there another command which selectively converts a given sample size of a cell?

[Cedric]

What is the structure of your data (cell array, valid cells content, invalid cells content)?

[Karen Hornsby]

just a plain old cell arry, 1 row and 56 cells all containing doubles.

[Matt J]

If your data is initially acquired as a file, how did it get into cell array form? Why would you import the file to a cell array if you ultimately want it to be a vector?

[Samira Abedi]

I get the following error when applying the above code:

Attempt to grow array along ambiguous dimension.

Answer 1

[Walter Roberson]

No, you cannot do that. So what you do instead is figure out where the smaller lines are and pad those rows with enough NaN to match the size of the other rows. Then you can cell2mat()

[Karen Hornsby]

What search term would I use to find append to cell?

[Walter Roberson]

prevlen = sum(cellfun(@length, C(end-1,:)));
lastlen = sum(cellfun(@length, C(end,:))));
C{end,end} = [C{end,end}, NaN(1,prevlen - lastlen)];

mat2cell(C)

[Joel Torby]

    C=yourCellArrayWithDifferentSizes; 
    maxLengthCell=max(cellfun('size',C,2));  %finding the longest vector in the cell array
    for i=1:length(C)
        for j=cellfun('size',C(i),2)+1:maxLengthCell
             C{i}(j)=0;   %zeropad the elements in each cell array with a length shorter than the maxlength
        end
    end
    A=cell2mat(C); %A is your matrix

Answer 2

[Jan]

What do you want as output for:

C = {[], 1, 1:2}

?

[Karen Hornsby]

Do you mean that the code above removes row 1 of column 1&2?

[Jan]

No, "C" is a cell, which contains vectors of different length. Simply copy it to the command window and run it. It is exactly what you have explained by:

 ... a cell array where some of the cells have different lengths?

Now you ask us for creating a matrix from such an input. So how should the output look like in this case?

Answer 3

[Samira Abedi]

I get the following error when I apply the suggested method:

Attempt to grow array along ambiguous dimension.