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SyneRBI / SIRF-Exercises

SIRF Training and demonstration material
http://www.ccpsynerbi.ac.uk
Apache License 2.0
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gradient descent notebook #193

Open KrisThielemans opened 1 year ago

KrisThielemans commented 1 year ago

the PET recon has a funny line image

Also, it is called gradient descent, but it is actually ascending due to some minus signs. Better to switch the sign in the PET, but keep it for MR and CT.

evgueni-ovtchinnikov commented 1 year ago

@KrisThielemans Which notebook are you referring to?

SIRF-Exercises notebook ML_reconstruction compares OSEM with gradient ascent, and so far as I remember, other PET notebooks in SIRF-Exercises do not deal with gradient descent too.

KrisThielemans commented 1 year ago

Synergistic/gradient_descent_mr_pet_ct.ipynb. No need to fix this now though. Next release!

KrisThielemans commented 1 year ago

b6b0d6be1bf7ce5a6d18090aa6a1879d286c1d98 edited the notebook a bit to warn people about the confusion on signs.

KrisThielemans commented 1 year ago

@ckolbPTB should we move this notebook to Introductory in the next release? There isn't anything "synergistic" here really, and it nicely follows up from the other ones in that folder.

KrisThielemans commented 1 year ago

@ckolbPTB what do you think about moving this to Introductory?

KrisThielemans commented 1 year ago

@evgueni-ovtchinnikov would you have time to change the sign here and adjust?

KrisThielemans commented 1 year ago

currently the "ascent" is addressed by updating text in the notebook. This is good enough for 3.5. We'll multiply the PET objective function with -1 and descend in the next version

KrisThielemans commented 3 months ago

Move now completed.

The only thing remaining here is the strange line in the PET reconstructions.