Write Stream Binary Header with different precisions

Hi @Jaden Hoechstetter,

You mentioned, “ _I want to write a stream binary file that has different precisions for the header. Below is the header that I want to include with 256 Characters for the name of the file, double precision for the number of rows and columns, and then the data set is single precision.256 Character -> "Unformatted file version=292498251"Double -> "13"Double -> "1000000"Single -> "data" which is an array with 1000000 x 13 entries,Any help would be appreciated!_ ”

Please see my response to your comments below.

To achieve the objective of writing a stream binary file with different precisions for the header in MATLAB, create string of 256 characters, followed by two double precision numbers and a dataset of single precision numbers with dimensions 1000000 x 13. Then, use MATLAB's file I/O functions to open a binary file for writing, write the header and the dataset to the binary file in the specified format and make sure that the file is properly closed after writing. Here is the complete MATLAB code that implements the above steps:

% Define the Header
headerString = 'Unformatted file version=292498251'; % Initial string
headerString = pad(headerString, 256); % Pad to 256 characters
numRows = 1000000; % Number of rows
numCols = 13; % Number of columns

% Generate the Data
data = single(rand(numRows, numCols)); % Create a 1000000 x 13 array of   
single precision random numbers

% Open a Binary File
fileID = fopen('output_binary_file.bin', 'wb'); % Open file for writing in 
binary  mode

if fileID == -1
  error('Failed to open the file for writing.');
end

% Write the Header and Data
% Write the header string (256 characters)
fwrite(fileID, headerString, 'char');

% Write the number of rows and columns (double precision)
fwrite(fileID, numRows, 'double');
fwrite(fileID, numCols, 'double');

% Write the data (single precision)
fwrite(fileID, data, 'single');

% Close the File
fclose(fileID);

% Display final results
disp('Binary file written successfully with the following contents:');
disp(['Header: ', headerString]);
disp(['Number of Rows: ', num2str(numRows)]);
disp(['Number of Columns: ', num2str(numCols)]);
disp(['Data Size: ', num2str(size(data))]);

Please see attached.

So, in the above code example provided,header string is initialized and padded to ensure it is exactly 256 characters long. This is crucial for maintaining the structure of the binary file. A dataset of random numbers is created using rand, which generates values between 0 and 1. The single function converts these values to single precision. Then fopen function is utilized which opens a binary file named output_binary_file.bin for writing. The 'wb' mode indicates that the file is opened for writing in binary format and Error handling is included to ensure that the file opens successfully. The fwrite function is used to write the header string, followed by the two double precision numbers (number of rows and columns), and finally the dataset of single precision numbers and fclose function is called to close the file, ensuring that all data is flushed and the file is properly saved. Finally, script concludes by displaying the contents of the header, the number of rows and columns, and the size of the data array to confirm that the operations were successful.

For more information on file functions used in the code above, please refer to

fopen

fwrite

<https://www.mathworks.com/help/matlab/ref/fclose.html?s_tid=doc_ta fclose >

Hope this should help resolve your problem. Please let us know if you have any further questions.