On Friday 13 April 2007 14:29, Matt Newville wrote:
Hi Victor,
It should be restraint_sum = restraint1 + restraint2 + restraint3 + ...
That is, a restraint should be a value that you'd like to me made as small as possible, but can take either sign. The restraints are simply appended to the "vector to be minimized" in the least squares sense.
I'm not sure that will fully solve the issue of having different results between 10+ individual restraints and fewer summed restraints. But I'm interested to hear and see more....
Given that individual restraints might be of either sign, you might consider adding them in quadrature and using the square root of that as the restraint. As Matt said, the details matter, but I think that would be a serviceable work around for more than 10 restraints. B -- Bruce Ravel ---------------------------------------------- bravel@anl.gov Molecular Environmental Science Group, Building 203, Room E-165 MRCAT, Sector 10, Advanced Photon Source, Building 433, Room B007 Argonne National Laboratory phone and voice mail: (1) 630 252 5033 Argonne IL 60439, USA fax: (1) 630 252 9793 My homepage: http://cars9.uchicago.edu/~ravel EXAFS software: http://cars9.uchicago.edu/~ravel/software/