MATLAB: Does saving and loading MAT-Files take so long in MATLAB R2014b

MATLABr2014bgraphics

Why does saving and loading MAT-Files take so long in MATLAB R2014b?

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In R2014b and later, if you save a graphics object in a MAT-file, MATLAB stores all the data for that object. When you load the MAT-file, MATLAB regenerates the objects. If the graphics object contains a lot of data, then the file might be large. Saving or loading large files can be slow.

In previous releases, if you save a graphics object to a MAT-file, MATLAB stores the object as a double. Storing a double does not require a large file. However, MATLAB cannot regenerate the object when you load the file.

Related Solutions

MATLAB: MAT files

p=load matfile1.mat
q=load matfile2.mat
save newmatfile.mat

MATLAB: Convert mat-files into CSV.files

d=dir(fullpath(dirname,'*.mat'));
for i=1:length(d)
  load(d(i).name     % will leave whatever variable is in mat-file in memory
  [p,n]=fileparts(d(i).name);         % get path, name w/o extension
  csvwrite([fullfile(p,n) '.csv'],X)  % write to name w/ .csv extension
end

The above use X as a placeholder for the variable containing the data LOADed; use whatever is that name. Of course, also assumes all the files are symmetric with the same name; if not use the functional form of load and the appropriate structure name retrieved.

And, of course, this begs the question of why one would do this... .mat files are much more accurate in keeping full precision whereas .csv files are a limited number of decimal places; are much faster to read/write and take up far less disk space besides (albeit that's pretty much a "don't care" item any more).

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Related Solutions

MATLAB: MAT files

MATLAB: Convert mat-files into CSV.files

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