Use the "-struct" option when saving MAT-files so that structure fields are saved as separate variables. You can then use the LOAD function to select particular variables from the MAT-file:
a.x = 1;
a.y = 2;
The "-struct" option is not available prior to MATLAB 7.0 (R14).
Using the "struct" flag causes each field of the structure to be individual variables in the MAT-file. To load them back into a structure use: