Sigma Clipping the 1-D Fit
The pictures below show the effect of using sigma
clipping in the
1-D Fit Package to reject data points.
The picture below shows a
Row Plot from an image showing a flat
background and a spike. We want to characterize the low-lying
background data, but the tall peak will corrupt the fit. One way to
exclude the spike from the fit is to use sigma clipping, which
rejects the spike as "bad data".
The picture below shows the same data as above, but
with the
1-D Fit Toolbar opened and configured for a 5-term
fit and no sigma clipping.
The picture below shows the result of fitting 5
coefficients without enabling sigma clipping. The spike pulls the
fit upward, causing extra ripples and making the fit useless for
characterizing the data along the base.
For the fit shown below, the was checked, then the was clicked to
compute a new fit. The rejected points were changed to the
turquoise color. The fit is in purple.
The picture below shopws a highly magnified view of
previous figure about the base of the peak. Notice how the fit
tracks the point data near the base of the profile. The upper and
lower sigma envelope is drawn in purple above and below the
fit.
Related Topics
1-D Fit Package
1-D Fit Toolbar
1-D Fit Properties
Using Point Deletion in the 1-D Fit
Mira Pro x64 8.67 User's Guide, Copyright Ⓒ 2023 Mirametrics, Inc.
All Rights Reserved.
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