In this case it is advisable to split the region into two or more distinct regions.
The figure shows a region, where a split is suggested at channel 138, because the type of the background drastically changes at this point.
The best tool to eliminate this faulty behavior is the region splitter tool.
To perform the region splitting:
HyperLab splits the region now into two halves, refits them and displays the result.
The figure shows the new region bounds around channel 138. Please note that a curved background chosen in the first region, while a stepped one in the second region, therefore the overall Chi-squared became better, and the residual changed to a smoother one.
Please take a closer look at the splitting position (use the Zoom in tool at the main toolbar). You can see that HyperLab has automatically created overlapping region bounds, thus the fit stability has been greatly increased.
This automatic region bound overlapping is one of the most powerful new features of HyperLab 2005.