TD_OutlierFilterFit Syntax Elements - Teradata® Database

Database Analytic Functions

Product
Teradata® Database
Release Number
17.10
Published
July 2021
Language
English (United States)
Last Update
2021-07-28
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B035-1206
lifecycle
previous
Product Category
Teradata Vantage™
TargetColumns
Specify the names of the numeric InputTable columns for which to compute metrics.
GroupColumns
[Optional] Specify the name of the InputTable column by which to group the input data.
Default behavior: Function does not group input data.
OutlierMethod
Specify one of these methods for filtering outliers:
Method Values Outside This Range Are Outliers
percentile [min_value, max_value].
tukey [Q1 - k*(Q3-Q1), Q1 + k*(Q3-Q1)]

where:

Q1 = 25th quartile of data

Q3 = 75th quartile of data

k = interquantile range multiplier (see IQRMultiplier)

carling Q2 ± c*(Q3-Q1)

where:

Q2 = median of data

Q1 = 25th quartile of data

Q3 = 75th quartile of data

c = (17.63*r - 23.64) / (7.74*r - 3.71)

r = count of rows in group_column if you specify GroupColumns, otherwise count of rows in InputTable

LowerPercentile
Specify a lower range of percentile to use to detect whether the value is an outlier.
Value 0 to 1 is supported. For Tukey and Carling, use 0.25 as the lower percentile.
UpperPercentile
Specify a upper range of percentile to use to detect whether the value is an outlier.
Value 0 to 1 is supported. For Tukey and Carling, use 0.75 as the upper percentile.
IQRMultiplier
Specify interquartile range multiplier (IQR), k, for Tukey filtering.
The IQR is an estimate of the spread (dispersion) of the data in the target columns (IQR = |Q3-Q1|).
Use k = 1.5 for moderate outliers and k = 3.0 for serious outliers.
Default: 1.5
ReplacementValue
Specify how to handle outliers:
Option Description
delete Do not copy row to output table.
null Copy row to output table, replacing each outlier with NULL.
median Copy row to output table, replacing each outlier with median value for its group.
replacement_value

(Must be numeric.)

Copy row to output table, replacing each outlier with replacement_value.
RemoveTail
[Optional] Specify whether to remove the upper tail, the lower tail, or both.
Default: both
PercentileMethod
Specify either the PercentileCont or the PercentileDISC method for calculating the upper and lower percentiles of the input data values.