Vocabulary: http://www.ivoa.net/rdf/UCDlist/
Author: V.Delouille@oma.be
Date: 2021-05-04
Nb of terms discussed together : 3
New Term: stat.skew
Action: Addition
Description: Statistical skewness, third moment of normalised data distribution function
Prefix: P
Rationale:
This term was proposed actually by Veronique Delouille after FITSKeyword evaluation for solar datasets.
Would complete the stat properties within the UCD tree.
Would be useful for other data as well.
Used-in: SDO/AIA FITS keywords
Discussion:
The statistical moments (except for the mean value) don't have the same units as the observed quantity, and thus those are another quantity extracted from the data. We propose to set the prefix to P.
New Term: stat.kurtosis
Action: Addition
Prefix: P
Description: Statistical kurtosis, fourth moment of normalised data distribution function
Rationale:
This term was proposed actually by Veronique Delouille after FITS Keyword evaluation for solar datasets.
Would complete the stat properties within the UCD tree.
Would be useful for other data as well.
Used-in: SDO/AIA FITS keywords
Discussion:
Skewness is related to the asymetry of the distribution, and the kurtosis help to identify outliers.
New Term: stat.mad
Action: Addition
Prefix: P
Description: Statistical median absolute deviation from median
Rationale:
This term was proposed actually by Veronique Delouille after FITS Keyword evaluation for solar datasets
this is a robust quantity to measure the spread of values in a data set when the statistic is not normal
Would complete the stat properties within the UCD tree.
Would be useful for other data as well.
Used-in:
Discussion:
Similar to stat.stdev, but using median operators instead of the mean.