6.6 GB mat file load error with MATLAB 2014b: Error using load Cannot read file

Hi,

I saved a 6.6 GB mat file with MATLAB 2014b previously and now I need to open it with the same computer and the same version of MATLAB.

I clicked the "open" button under the "HOME" tab in the MATLAB window and found the mat file and "open". However, MATLAB gave me this:

Error using load Cannot read file D:\MATLAB & Simulink Simulation Results\XXX\XXX.mat.

I tried to change the path but it could not work.

Do you know how can I load the large mat file to the workspace?

Thank you in advance!

[Alka Nair]

Hi, Could you provide a snapshot of the error message?

Thanks, Alka

[Junfei Tang]

Thank you for your reply. Here it is:

Answer 1

[Jan]

There can be many different problems: Perhaps you do not have enough free RAM? Or the file is damaged? So please post the complete error message. Did you try to use the load command?

[Junfei Tang]

Thank you for your reply. I tried to use load command but:

Previous I load a small file like 200 MB, the "load" command works fine. In addition, the 6.6 GB file is saved in '-v7' instead of '-v7.3'.

The problem should not come from RAM since I have 16 GB in the computer and once the RAM is not enough, the computer just shuts itself down, but this time it did not.

[Junfei Tang]

Maybe MATLAB cannot detect '-v7' and '-v7.3' automatically, which means I must inform MATLAB of the mat file version, otherwise MATLAB will load the '-v7' mat file through the '-v7.3' way and cannot understand the file? But how to inform MATLAB of this?

[Walter Roberson]

MATLAB automatically detects -v7 and -v7.3 files and handles them as required.

Try

[fid, message] = fopen('D:\MATLAB & Simulink Simulation Results\XXX\XXX.mat');
if fid < 0
   fprintf('file could not be opened because: |%s|\n', message);
else
   firstline = fgetl(fid);
   fclose(fid);
   fprintf('first line of file is: |%s|\n', firstline);
end

This will give a hint as to whether the file is missing or unopenable or not a .mat file at all.

Also, try

whos('-file', 'D:\MATLAB & Simulink Simulation Results\XXX\XXX.mat')

[Alicia Cardona]

Hi! I have the same problem, just saved my workspace yesterday and the .mat file is only 3.67GB, but still gives me the same error message that it cannot read the file. Walter Roberson I tried your code and it gave me this: first line of file is: MATLAB 5.0 MAT-file, Platform: PCWIN64, Created on: Tue Jun 07 21:11:40 2016 IM & xœãc``0 b6 æ€Ò À

what can I do now?

[Walter Roberson]

What does whos -file report for the file?

See also

http://www.mathworks.com/matlabcentral/answers/98890-how-do-i-recover-data-from-a-corrupt-mat-file

http://www.mathworks.com/matlabcentral/fileexchange/6893-matcat-mat-file-corruption-analysis-tool

[Alicia Cardona]

     Name                         Size                   Bytes  Class     Attributes
  % 
  %   Fs                           1x1                        8  double              
  %   PSP                   21120001x1                168960008  double              
  %   PSP2                  21120001x1                168960008  double              
  %   PSP2_01_duration             1x1                        8  double              
  %   PSP2_01_end                  1x1                        8  double              
  %   PSP2_01_start                1x1                        8  double              
  %   PSP2_90               14252661x1                114021288  double              
  %   PSP2_90_peak                 3x1                       24  double              
  %   PSP_01_duration              1x1                        8  double              
  %   PSP_01_end                   1x1                        8  double              
  %   PSP_01_start                 1x1                        8  double              
  %   RMS_dB                       1x1                        8  double              
  %   SL1                       2048x1                    16384  double              
  %   a                            1x9                       72  double              
  %   a1                           1x9                       72  double              
  %   ans                          1x1                        8  double              
  %   b                            1x9                       72  double              
  %   b1                           1x9                       72  double              
  %   e                     21120001x1                168960008  double              
  %   e_1                   21120001x1                168960008  double              
  %   em                    21120001x1                168960008  double              
  %   em_1                  21120001x1                168960008  double              
  %   f                            1x2048                 16384  double              
  %   file                         1x83                     166  char                
  %   g                            2x2                       32  double              
  %   g1                           2x1                       16  double              
  %   g1_1                         2x1                       16  double              
  %   g2                           2x1                       16  double              
  %   g2_1                         2x1                       16  double              
  %   g3                           2x2                       32  double              
  %   g_1                          2x2                       32  double              
  %   k5                           1x1                        8  double              
  %   k5_1                         1x1                        8  double              
  %   k95                          1x1                        8  double              
  %   k95_1                        1x1                        8  double              
  %   path                         1x63                     126  char                
  %   peak                         1x1                        8  double              
  %   peak_dB                      1x1                        8  double              
  %   rms                          1x1                        8  double              
  %   rms_dB                       1x1                        8  double              
  %   rms_peak                     1x1                        8  double              
  %   rms_peak_dB                  1x1                        8  double              
  %   wave                  63985786x2               1023772576  double              
  %   wave_f                63985786x2               1023772576  double              
  %   wave_f2               63985786x2               1023772576  double              
  %   wave_f2_2             63985786x1                511886288  double              
  %   wave_f_2              63985786x1                511886288  double

thanks I'll check them now!

[Walter Roberson]

It appears that there is the potential for recovering some portions of the file.

[Alicia Cardona]

Oh really? how could I do so? thank you! I have some weird problem with the mathworks file exhange website as it doesn't download the folders from the links you send me...

[Walter Roberson]

If you have R2013b or later you should be able to use

supportPackageInstaller

to install the package.

Answer 2

[Junfei Tang]

Thank you very much everyone!

Sorry that I did not reply to you until now.

I discarded my old mat file since I was informed that the setup for the simulation should be modified afterwards. Then I rerun the simulation and saved the workspace data as a mat file in version "-v7.3":

Home / Preferences / General / MAT-Files: MATLAB version 7.3 or later (save -7.3)

Later on, when I needed to use the data, the new mat file in "-v7.3" was loaded without problem.

This is what I have experienced and anyone who encounters the same problem may refer to this.

Thank you for your attention again!

Sincerely,

Junfei Tang