AFNI Message Board

Dear AFNI users-

We are very pleased to announce that the new AFNI Message Board framework is up! Please join us at:

https://discuss.afni.nimh.nih.gov

Existing user accounts have been migrated, so returning users can login by requesting a password reset. New users can create accounts, as well, through a standard account creation process. Please note that these setup emails might initially go to spam folders (esp. for NIH users!), so please check those locations in the beginning.

The current Message Board discussion threads have been migrated to the new framework. The current Message Board will remain visible, but read-only, for a little while.

Sincerely, AFNI HQ

History of AFNI updates  

Previous Message Next Message
Message List New Topic Print View
|
Daniel Glen
April 23, 2008 05:33PM
Hi Yi,

There are two basic methods for solving for the tensor in our software, the linear and non-linear methods. The non-linear methods includes three choices for optimization for the search for the lowest cost positive definite solution, Gradient Descent, Powell NEWUOA and Hybrid. The Powell method gives the lowest cost, but is slower than the gradient search. The hybrid method is the default method and combines the two using the Powell method at the usually relatively few voxels that are highly anisotropic. Usually these points are at a relatively few very noisy voxels.

Daniel
Reply Quote
RSS
Subject Author Posted

3dDWItoDT very slow

Yi Jiang April 23, 2008 03:54PM

Re: 3dDWItoDT very slow

Daniel Glen April 23, 2008 05:33PM

Re: 3dDWItoDT very slow

Yi Jiang April 24, 2008 01:03PM

Re: 3dDWItoDT very slow

Daniel Glen April 24, 2008 02:22PM

Re: 3dDWItoDT very slow

Yi Jiang April 24, 2008 02:58PM

Re: 3dDWItoDT very slow

Daniel Glen April 29, 2008 04:16PM