When determining Da and Rhom, is it acceptable to lump all the (scaled)
data into one file and determine a single Da and Rhom for the whole lot?
The convention in the literature seems to be to determine Da and Rhom
for one data set and the estimate Da for all other data sets by scaling
the calculated Da by the appropriate gyro_mag/bond length ratios. The
current Xplor_NIH convention seems to be to scale all data to NH and
then choose a single Da and rhom for all data sets that is close to the
Da and rhom values for the individual scaled data sets. I'm a little
leery of these using either of these conventions because I have few data
points (21 CH and 10 NH), and if I run the scaled individual data sets
through SVD I get fairly different values for da and rhom between the
two data sets (14.04/.093 for scaled CH and 8.86/.057 for NH). {For
comparison, I ran the individual data sets in eginput/gb1_rdc through
SVD and got very similar Da and rhom values} My thought was then to lump
the scaled data together since, in general, more data points = more
accurate results. Is this a fair assumption? Are there better ways I
could go about this?
Thanks,
Andrew Borgert
