SOMO SAXS/SANS Residuals

| # Manual

## US-SOMO SAXS/SANS curve fitting residuals graph

###
Last updated: April 2012

US-SOMO SAXS/SANS operations involving curve matching, scaling or fitting will produce residuals graphs, which can be toggled between three different visualization modes:

In the graph above, the difference between the calculated and the experimental I(q) points divided by the associated experimental SD are plotted as a funtion of q. The two horizontal white lines indicate the +/- 2 SD which is customarily used as limits for a good fit.

Alternatively, the data can be viewed as a % delta [100 * (I(q)calc - I(q)expt) / I(q)expt] by clicking on the Plot as percent checkbox:

Here we have added two horizontal lines indicating 5% limits of the residuals. We think that this way of plotting the residuals better takes into account the wide variation in both intensity and associated SD values along the q range usually accessed in SAXS experiments.

The same residuals can by also plotted using a log scale by clicking on the Plot log checkbox:

www contact: Emre Brookes

This document is part of the UltraScan Software Documentation distribution.
Copyright © notice.
The latest version of this document can always be found at:

http://somo.aucsolutions.com

Last modified on April 26, 2012.