I was wondering if you could clarify what's the cause of the following behavior. I have a triangular mesh surface (.surf) that was created using mne_convert_surfaces from a .tri file. Now, I'd like to only use some of the points on the surface (i.e. decimate it), so I'm using mne_setup_source_space for that. I get a reduction in the number of sources up to spacing = 3 (from 40962 sources to 2562), but anything higher than that gives me the same number of sources. If I plot the "poka-dot" surface, I can see that there is still plenty of room for further decimation.
Is there anything in the decimation algorithm that prevents further decimation after a certain ratio? Or should I be checking my surface for some specific malformations?
Note that this is not a MEG problem, so I'm using the terminology of sources mostly to make it easier. The actual issue is simply decimating a surface. I'm just using the MNE tools because I'm familiar with them and this way I don't have to re-code these procedures I thought about implementing my own decimation, but if you know of standard algorithms to decimate a surface, preferably already implemented in Python, I'd appreciate it if you could point me to it.
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loaded lh.cortex 2562/40962 selected to source space (approx. spacing = 3 mm)
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Any other spacing bigger than that gives me the same numbers. For example:
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loaded lh.cortex 2562/40962 selected to source space (approx. spacing = 20 mm)
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If I try a different surface, I can get to a smaller (extreme) number of sources, which made me wonder if there was anything specific in the decimation algorithm about the ratio of decimated / original vertices:
I thought about implementing my own decimation, but if you know of standard algorithms to decimate a surface, preferably already implemented in Python, I'd appreciate it if you could point me to it.