MATLAB: How to delete a variable in a MAT-file, which corresponds to an instance of matlab.io.MatFile

Question

Background

I use an instance of &nbsp matlab.io.MatFile &nbsp to store and manipulate huge variables. (Huge compared to the capacity of my PC.) During the development of my code I create too many useless variables in the mat-file. The size of the mat-file and the number of variables increases.

The mat-file is version v7.3, which is an HDF5-file. With HDF5 there is no easy way to delete a dataset and recover the space. It is possible to "unlink" a variable and copy the HDF5-file to a new one.

Question

How to delete a variable in a MAT-file, which corresponds to an instance of &nbsp matlab.io.MatFile ? &nbsp Is there a better way than copy the variables, which I want to keep, to a new mat-file and delete the old one?

Answer 1

See https://www.mathworks.com/matlabcentral/answers/254048-how-can-i-delete-variables-in-my-mat-file-without-loading-them-into-matlab-7-2-r2006a#comment_472754 for code by Matt J