How do I convert a cell array to matrix whose dimensions are not equal?

mydata = 

      [195x1 double]    [124x1 double] [1826x1 double] [2x1826 double] [195x124x1826 single]

[Guillaume]

Convert into what?

For what purpose?

[Geoff Hayes]

Manoj - are you trying to convert the above to a matrix using cell2mat? If so, what are the dimensions of the matrix that you are trying to obtain? Please show the code that you have written that generates the error.

[Manoj]

Geoff Hayes

Pls find the attachment of the .jpg images having the cell array of B consists the data of different dimensions. I need to convert the cell array in to matrix form with different file names, so that I can choose the data for plotting.

Thanks

Manoj Kumar

[Jan]

I neither understand the meanig of the images, not the description "matrix form with different file names".

[Geoff Hayes]

Manoj - how should all of this data, from your cell array, be packaged into the matrix? What should the dimensions be for the matrix?

Answer 1

[Walter Roberson]

%using variable names from your posting, structure as in capture.JPG
md1 = mydata{1};
md2 = mydata{2};
md3 = mydata{3};
md4 = mydata{4};
md5 = mydata{5};

[X, Y, Z] = ndgrid(md1, md2, md3);
pointsize = 20;
scatter3(X(:), Y(:), Z(:), pointsize, md5(:));

%using variable names from data file.JPG
%the data is a mix of int16 and int32 and we need to make it all the same datatype to
%make it into a numeric matrix without risk that the wrong datatype would be used

temp = cellfun(@(M) int32(M.'), permute(B,[1 3 2]), 'Uniform', 0);
B30 = cell2mat( arrayfun(@(R) horzcat(temp{R,:}), 'Uniform', 0) );

The result of this, B30, would be a 30 x 10666 numeric array, in which each row is formed by concatenating together the 2446 x 1, 2532 x 1, 2651 x 1, 3037 x 1 as one piece and making that a row.

[Manoj]

Thank you for your reply

but I am getting two errors after running the below code.

1)

md = mydata{1};
md1 = mydata{2};
md2 = mydata{3};
[X Y Z]=ndgrid(md,md1,md2);
temp = cellfun(@(M) int32(M.'), permute(B,[1 3 2]), 'Uniform', 0);
B30 = cell2mat( arrayfun(@(R) horzcat(temp{R,:}), 'Uniform', 0) );
Error using repmat
Requested 5949x5949x5949 (1568.6GB) array exceeds maximum array size preference. Creation of arrays greater than this
limit may take a long time and cause MATLAB to become unresponsive. See array size limit or preference panel for more
information.
Error in ndgrid (line 73)
        varargout{i} = repmat(x,s);

[Manoj]

2)

md = mydata{1};

md1 = mydata{2};

[X Y]=ndgrid(md,md1);

temp = cellfun(@(M) int32(M.'), permute(B,[1 3 2]), 'Uniform', 0);

B30 = cell2mat( arrayfun(@(R) horzcat(temp{R,:}), 'Uniform', 0) );

Error using arrayfun

All of the input arguments must be of the same size and shape.
Previous inputs had size 7 in dimension 2. Input #3 has size 1

[Walter Roberson]

You have changed the size of your data in mydata. Please show the current summary of mydata and also of B.

The line

B30 = cell2mat( arrayfun(@(R) horzcat(temp{R,:}), 'Uniform', 0) );

should be

B30 = cell2mat( arrayfun(@(R) horzcat(temp{R,:}), 1:size(temp,1), 'Uniform', 0) );