cell part not saved using '-struct' option

Hi:

I have a structure variable 'ImaInfo' like below:

then I saved it into disk using '-struct' option, using command:

save('test.mat','-struct','ImaInfo')

but the variable data in the struction ('ImaInfo.data') is not saved in the 'test.mat' file, as shown below:

just want know if there is any mistake with my operation? or 'cell' type is not allow to save in '-struct' option?

Thanks!

Yu

[Walter Roberson]

In my quick test in R2019a, all three fields show up for me.

[Yu Li]

Hi Walter:

I tried both 2018a and 2018b the result is the same.

Thanks!

Yu

[Steven Lord]

Did you receive any warning message when you tried saving the struct array? If so what is the full text of that warning (all the text displayed in orange?)

Are you certain you're using the built-in save function? What does this return?

which -all save

What type of data is stored inside the cell array named data?

[Walter Roberson]

Is it possible that the data field contained over 1 gigabyte ?

[Yu Li]

Hi Steven:

there is no warning.

below is the result of which -all save:

>> which -all save 
built-in (/apps/matlab/R2018b/toolbox/matlab/general/save)
save is a Java method                                                                                % com.mathworks.services.Prefs method
/apps/matlab/R2018b/toolbox/matlab/codetools/+matlab/+desktop/+editor/@Document/Document.m           % matlab.desktop.editor.Document method
save is a Java method                                                                                % com.mathworks.mde.editor.MatlabEditor method
save is a Java method                                                                                % com.mathworks.matlab.api.editor.Editor method
/apps/matlab/R2018b/toolbox/matlab/appdesigner/appdesigner/+appdesigner/+internal/+model/AppModel.m  % appdesigner.internal.model.AppModel method
/apps/matlab/R2018b/toolbox/matlab/winfun/@COM/save.m                                                % COM method
/apps/matlab/R2018b/toolbox/simulink/simulink/@slxPackager/save.p                                    % slxPackager method
/apps/matlab/R2018b/toolbox/sl3d/sl3d/@vrworld/save.m                                                % vrworld method

the data inside the 'ImaInfo.data' is 'unit8' matrix which obtained from 'imread':

Hi Walter:

the file is very large: ~700Mb.

Thanks!

Yu

[Walter Roberson]

The cell array contains more than 4 gigabytes and so needs the -v7.3 flag to save

[Yu Li]

the totally size is 700Mb, which is less than 4Gb

[Walter Roberson]

The limitation is not on the compressed size of the data: it is on the raw size of the data including the uncompressed headers.

[Yu Li]

I tried the '-v7.3' option, yes, the parameter is successfully saved. but I have one more question:

the size of original file is: 778436Kb

the size of compressed file is: 778431Kb

the usage of '-v7.3' only reduced 5Kb of the disk size, do you think this weird?

Thansk!

Yu

[Walter Roberson]

V7.3 is not a compression specification. V7.3 uses a completely different internal format for data that is able to hold large variables where the old format included size counters that were limited to 1 gigabytes.