MATLAB: How to enter extensive data to cell array

cellarrayfunction

I am trying to store some extensive data to a cell array with specification:

{1×1}, {1}[… x 5]
Take the first five columns
Ignore the first two lines and take all the rows following
Ignore the white spaces character ('') between columns
Store the data on the variable "Time"

The data should appear on the Workspace like this,

   Time =
          2013           2          23          21          30
   %This is just one row of the data

The data is in this link,

http://www.ndbc.noaa.gov/data/realtime2/41053.txt

So far I have proceed the following way,

 function    Data = SJ 
 fid = fopen( 'SJ.txt' );
        Data = textscan( fid, '%d%d%d%d%d' ...
                    ,   'Delimiter'             ,   ' '     ...
                    ,   'HeaderLines'           ,   2       ...
                   );
        fclose( fid );
    end

Could you please help?

Best Answer

fid = fopen( 'SJ.txt', 'rt' );
DataCell = textscan(fid, '%d%d%d%d%d%*[^\n]', 'HeaderLines', 2, 'Collect', 1) ;
fclose(fid);
Time = cell2mat(DataCell);

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MATLAB: How to create a cell array of different data type

Documentation says:

    A = cell2mat(C) converts cell array C with contents of the **same** data type 
    into a single array, A.

Thus

    Data = cell2mat(DataCell);

is not possible in your case since DataCell contains both numeric and character data.

However, DataCell as returned by textscan is close as is

    cell_array_of_different_data_type = DataCell{1};

MATLAB: How to access images from directories using an input command for the extensive file

In the example function you gave the second input 'fileType' is not used, is that the problem?

You could use this in the line calling fullfile to get only the filetypes you want, i.e.:

function [filenames] = GenerateImageList(dirname, fileType)
    fileIdentity = fullfile(dirname, ['*' fileType]);
    files = dir(fileIdentity);
    for i = 1:length(files) 
        filenames = files(i).name;
        fprintf('%s\n', filenames);
    end
end

For example you can run this code as:

filenames = GenerateImageList(pwd,'png')
% or
filenames = GenerateImageList(pwd,'jpg')

However, there are some problems with your code - if there are no files with the extension you ask for the function throws an error because filenames is left undefined. Also, I think you want filenames to contain a list of all the filenames? But the way it is written here it will only ever contain the last filename it found because you overwite it on every loop. Might I suggest something like this:

function [filenames] = GenerateImageList(dirname, fileType)
    fileIdentity = fullfile(dirname, ['*' fileType]);
    files = dir(fileIdentity);
    filenames = {files(:).name};
    fprintf(1, '%s\n', filenames{:})
end

If you don't need to display the text in the command window for every filename (why do you want that?) you can just call dir directly for the filename list:

function [filenames] = GenerateImageList(dirname, fileType)
    df = dir(fullfile(dirname, ['*' fileType]));
    filenames = {df(:).name};
end

And then maybe you don't need the GenerateImageList function at all, you could just put those lines of code directly inb the parent function...

Hope this helps,

Best Answer

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MATLAB: How to create a cell array of different data type

MATLAB: How to access images from directories using an input command for the extensive file

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