When playing a bit with the result files of Dymola 2012 I discovered an strange behaviour in the structure of the saved mat-files. Until now I’ve seen three variants of these files:

1. The format of the regular result files saved automatically by the simulation process. This format is also used by OpenModelica and can be read with DyMat.
2. When using “Save Result As” in the result browser and choosing “Result files (*.mat)” for the file format the saved file is almost identical to 1. but some matrices are transposed.
3. When using “Save Result As” in the result browser and choosing “Result files – Only Plotted (*.mat)” the saved file uses a much simpler structure.

For me this makes no sense! Maybe there’s some deeper concept behind it, but I don’t see it yet. Nevertheless I plan to implement all three variants in my DyMat package in the future.

The information on the variant seems to be coded in the “Aclass” variable. This structure differs in a number which looks like a version (1.0 and 1.1) and the strings “binNormal” and “binTrans“. This can be used to handle files in an different way, but I will do more testing.