SAXNS Cross-Chi-squared Calculator

This server estimates the cross-Chi² metric between two SAXS data sets.
This metric depends on the data being accurately Scaled. Remove low-q data from poorly matched data for a better fit.
Note: removing too much low-q data from the Fitting process may result in a worse fit.

Select the First Saxs Data file:

Select the Second Saxs Data file:

Plot size (png)

Minimum Q (Å^-1):
(Remove any parasitic scattering from beamstop)

Maximum Q (Å^-1)
(Limit to useful data range - do not include random noise from high-q)

Your e-mail:	Fitting Parameters:	{opt q - Ignore}

	(Ignore low-q data -	*Use caution q_ignore> 0.050)

Calculate XC:

Caveats

Q-values in files should match - but this is not necessary (Max 2,000)
Closest q-value pairs are matched
Scaling does not use weights - needs low-q data
X² is not always symmetric (1-2 vs 2-1) - Depends on Scaling
Exclude low-q data from Scaling if data are a poor match in this region. - May improve fit and lower Chi²
Excluding low-q data from Scaling may result in a poor fit and higher Chi²