Increase execution speed of saving using matfile

I want to continously save data (in appdesigner if that is relevant), therefore I create a matfile object on startup and then append data using a timer:

"Main"

app.SavingObject = matfile(app.FileName,'Writable',true);

And in a timer:

app.SavingObject.Data(app.sizeMyVar(1)+1:app.sizeMyVar(1)+size(NewPoints,1),1:app.sizeMyVar(2)) = NewPoints;

This will append my Data in the correct way.

What bothers me, if profiling this, you will see, that 40% of the time is spent internally using "whos". Sure this can be adjusted by the amount of how much data is written per call (I write ~60k Values per call), but it somehow feels like a waste of time and the amount of data per call is kind of fixed in my setup.

Is there a way to increase the wrtiting speed?

Answer 1

[Jan]

A MAT file can contain a set of variables and store the data in compressed form. Appending new data to an existing variable is expected to be slow. It would be much more efficient to use a binary file and export the data to the MAT file at the end of the process at once.

Answer 2

[Pritesh Parmar]

Hi Stefan,

I had the similar issue with MATLAB's "save -append" with updating variables with large dataset. Does the the following code work for you?: fastSaveUpdate - Efficiently update variables in MAT-file - File Exchange - MATLAB Central

Pritesh Parmar