Write binary file in Matlab

Hello,

I have a binary data generated by Fortran, I am able to read my data:

    fid = fopen('inflow.data0000');
    sep1=fread(fid,1,'float');
    nynzitime=fread(fid,3,'int32');
    sep=fread(fid,1,'int32');
    RAW_read = fread(fid, 3*n1*n2,'float32');
    RAW = reshape(RAW_read, [n1,n2,3]);
    fclose(fid);

I need to make some changes in the data and then write it out as a binary file for Fortran.

so I did this:

    fileID = fopen('newinflow.data0000')
    fwrite(fileID,sep1,'single');
    fwrite(fileID,nynzitime,'int32');
    fwrite(fileID,sep,'int32');
    fwrite(fileID,RAW_read,'float32');
    fclose(fileID);

then when Fortran reads the data:

      namel='newinflow.data0000'
      open(30,file=namel,form='unformatted')
      read(30)n2al,n3l
      read(30)qal(0:n2al+1,1:n3l,1:3)
      close(30)

error message shows "corrupted file". I realized that it is a header/format related issue, but I am not familar with binary file, tried a few different things, no luck yet.

I attached a 'good' binary data, please see if you know how to read and write it properly for Fortran.

Thank you for your time.

Answer 1

[James Tursa]

Can you read and write as “STREAM” in your FORTRAN compiler? No header stuff to worry about.

[Haoliang Yu]

Yep, that is something I will do today.

Answer 2

[Image Analyst]

Maybe try changing the ENDIAN?

[Haoliang Yu]

I tried, no luck. I think the problem is the first 4 bytes, I am not sure how to read it properly, for matlab, it doesn't matter what it is, so I couldn't write it back correctly.

[Image Analyst]

Why are you not specifying 'w' or 'r' in your fopen()? Does it somehow figure it out afterwards?

[Haoliang Yu]

Oh, I did, but forgot that part when I paste the code here...also I worked around this problem by changing the Fortran write and read code to STREAM.

[Image Analyst]

A paste operation shouldn't drop out characters that were copied into the clipboard. You might want to investigate that.