7.00.02 - VectorDistance Arguments - Aster Analytics

Teradata Aster® Analytics Foundation User GuideUpdate 2

Product
Aster Analytics
Release Number
7.00.02
Release Date
September 2017
Content Type
Programming Reference
User Guide
Publication ID
B700-1022-700K
Language
English (United States)
TargetIDColumns
Specifies the names of the columns that comprise the target vector identifier. You must partition the target input table by these columns and specify them with this argument.
TargetFeatureColumn
Specifies the name of the column that contains the target vector feature name (for example, the axis of a 3-D vector).
The function drops any entry that has a NULL value in a feature_column.
TargetValueColumn
[Optional] Specifies the name of the column that contains the value for the target vector feature. If you omit this argument, each feature (that is, each row) has the target value 1.
The function drops any entry that has a NULL value in a value_column.
RefIDColumns
[Optional] Specifies the names of the columns that comprise the reference vector identifier. Default: TargetIDColumns value.
RefFeatureColumn
[Optional] Specifies the name of the column that contains the reference vector feature name. Default: feature_column (TargetFeatureColumn value).
The function drops any entry that has a NULL value in a feature_column.
RefValueColumn
[Optional] Specifies the name of the column that contains the value for the reference vector feature. Default: TargetValueColumn argument value.
The function drops any entry that has a NULL value in a value_column.
RefTableSize
[Optional] Specifies the size of the reference table. Default: 'SMALL'. Specify 'LARGE' only if the reference table does not fit in memory, because 'SMALL' allows faster processing.
DistanceMeasure
[Optional] Specifies the distance measures that the function uses. Default: 'cosine'.
IgnoreMismatch
[Optional] Specifies whether to drop mismatched dimensions. Default: 'true'. If DistanceMeasure is 'cosine', this argument is 'false'.

If you specify 'true', then two vectors with no common features become two empty vectors when only their common features are considered, and the function cannot measure the distance between them.

ReplaceInvalid
[Optional] Specifies the value to return when the function encounters an infinite value or empty vectors. For custom, you can supply any DOUBLE PRECISION value. Default: 'PositiveInfinity'.
TopK
[Optional] Specifies, for each target vector and for each measure, the maximum number of closest reference vectors to include in the output table. For k, you can supply any INTEGER value. Default: maximum INTEGER value (2,147,483,647).
MaxDistance
[Optional] Specifies the maximum distance between a pair of target and reference vectors. If the distance exceeds the threshold, the pair does not appear in the output table.

If the DistanceMeasure argument specifies multiple measures, then the MaxDistance argument must specify a threshold for each measure. The ith threshold corresponds to the ith measure. Each threshold can be any DOUBLE PRECISION value.

Default behavior: The function returns all results.