The Lmax

Hello MRTrixler,

Question: I remember MRTrix 0.2 and I had to choose the lmax (lamx 12 for the 128 directions).
How is it now? If I open ODFs in MRView it allways switshes to lmax8. Does that something mean or is it just a default value?
And…if I have 128 directions will it be reflect somehow what I can choose in mrview?



Hi Ralf,

When an SH image is opened in the ODF tool in mrview, it should default to displaying the lmax corresponding to the ODF image data. It is more likely that your lmax was reduced to 8 earlier in your processing chain: your ODF image was actually calculated and stored with an lmax of 8, and therefore that’s what mrview will display.

The mechanisms used to determine lmax when the -lmax option is not explicitly provided are described here.


Thanks for the answer,
I read a little arround, but could not fully understand why my 128 directions were reduced to 8 lmax.
I will test it with 3T data and 7T with the -lmax 16 option.