STScI Logo

samplepars stsdas.analysis.fitting


NAME · USAGE · DESCRIPTION · PARAMETERS · SEE_ALSO

NAME

samplepars -- Edit parameters related to data sampling and rejection.

USAGE

samplepars

DESCRIPTION

The points to be fit are determined by selecting a sample of data specified by the parameter sample and taking either the average or median of the number of points specified by the parameter naverage. The type of averaging is selected by the sign of the parameter and the number of points is selected by the absolute value of the parameter.

If niterate is greater than zero the sigma of the residuals between the fitted points and the fitted function is computed and those points whose residuals are less than LOW_REJECT * sigma or HIGH_REJECT * sigma value are excluded from the fit. Points within a distance of grow pixels of a rejected pixel are also excluded from the fit. The function is then refit without the rejected points. The rejection can be iterated the number of times specified by the parameter niterate. Note a rejection value of zero is the same as no rejection.

PARAMETERS

(axis = 1) [integer, min=1, max=INDEF]
Axis onto which to project if fitting an image section of more than one dimension. It is relative to the full image, and not to the particular section being fitted. For instance, when fitting the section data[100:*:*], axis can have either a value of 2 or 3. Notice that redundant section constructs such as dev$pix[256:256,*] will not work.
(sample = *) [string]
Sample points to use in fit. The default (*) is to set the sample to the full data range. Sub-ranges may be specified by two real numbers separated by a colon. Any number of sub-ranges are allowed, separated by commas or spaces. The numbers must be in the same units as the X-axis.
(naverage = 1) [integer]
Number of points to be used in sample averaging.
(low_reject = 0.) [real, min=0., max=INDEF]
Lower threshold (in sigma) of the fit. Values below this level will be rejected.
(high_reject = 0.) [real, min=0., max=INDEF]
Upper threshold (in sigma) of the fit. Values above this level will be rejected.
(niterate = 1) [integer, min=0, max=INDEF]
Number of rejection iterations.
(grow = 0.) [real, min=0., max=INDEF]
Rejection growing radius (in pixels).

SEE ALSO

gfit1d, nfit1d, ngaussfit


Package Help · Search Form · STSDAS