"Out of memory" error during GND density calculation from large EBSD datasets

[nbauermcl]

Hello, I am trying to calculate the GND density in a deformed BCC iron specimen from an EBSD map with over 17 million datapoints (over 13 million indexed). I am using MTEX version 5.10.0 together with Matlab version R2023a on a 64-bit Windows 10 Pro system with 32 GB RAM. I stick to the calculation method described in https://mtex-toolbox.github.io/GND.html.

However, the rotation of the BCC dislocation system into the specimen reference frame dSRot = ebsd.orientations * dS has so far always produced an "out of memory" error for me. Specifically, it occurs during one of the computationally heavy rotation steps, i.e. at line 25 or 26 in the rotate_outer.m file (path to mtex\geometry@vector3d\rotate_outer.m) which reads something like v.x = (a.^2+b.^2-c.^2+d.^2)*x + ...

Has anyone else encountered such an error with large EBSD datasets? And does anyone have a solution how to make the calculation work on my PC with 32 GB RAM?

Thanks for your help!