cell2mat command not giving expected result

Error using cat

Dimensions of arrays being concatenated are not consistent.

Error in cell2mat (line 83)

m{n} = cat(1,c{:,n});

Error in classification (line 12)

testing_data = cell2mat( tst_data ) ;

I'm getting the above error on trying to convert the 102x12 dimension cell type variable "tst_data" into a numeric matrix to be stored in testing_data. Tried checking if any of the elements are empty-arrays, hence resulting in the concatenating error. Ran the correction code to eliminate empty arrays nevertheless. Still the error persists. The code snippet calling cell2mat function is as follows:

isEm = cellfun( @isempty, tst_data ) ;

tst_data(isEm) = {NaN} ;

testing_data = cell2mat( tst_data ) ;

Can't figure out what the issue is or how to fix this. Would appreciate any help...

Answer 1

[Jan]

There are no empty array in the provided data, but the sizes of the vectors differ: all are row vectors, but they have between 16 and 21 elements. Then you cannot concatenate them to a matrix.

data = load('tsts_data.mat');
L = cellfun('size', data.tst_data, 2)

% 18    16    17    17    17    17    18    18    18    17    17    18
% 18    16    17    17    17    17    18    19    18    17    17    18
% 18    16    17    17    17    17    19    18    18    17    17    19
% 17    16    17    17    17    17    18    18    17    19    17    18
% 17    16    17    17    17    17    18    18    17    18    17    17
% 17    16    17    17    17    17    19    19    17    18    17    18
% 17    16    17    17    17    17    19    19    17    18    17    18
% ...

Replacing empty arrays by NaNs would not be useful, because the sizes still do not match.

What is the wanted output?