Scan_DTW_Sakoe_Chiba_Constraint function

The Scan_DTW_Sakoe_Chiba_Constraint function returns time series data that matches a pattern using dynamic time warping distance with the Sakoe-Chiba constraint.

Syntax

Scan_DTW_Sakoe_Chiba_Constraint (
                 ts                  TimeSeries,
                 ident               LVARCHAR,
                 col_name            LVARCHAR,
                 begin_tstamp        DATETIME YEAR TO FRACTION(5),
                 end_tstamp          DATETIME YEAR TO FRACTION(5),
                 pattern             LIST (ROW (DOUBLE PRECISION) NOT NULL),                         
                 enlarge_threshold   DOUBLE PRECISION, 
                 norm_mconstraint    DOUBLE PRECISION,
                 dtw_threshold       DOUBLE PRECISION) 
RETURNS LIST (SEARCHROW NOT NULL)
ts
The time series value for the specified primary key.
ident
A string identifier that is associated with the time series instance.
col_name
The name of the column in the TimeSeries data type from which to retrieve the values.
begin_stamp
The begin point of the range to search. Can be NULL, which represents the first element in the time series.
end_stamp
The end point of the range to search. Can be NULL, which represents the last element in the time series.
pattern
A search pattern that is returned by the ValueAsCollection or TSGetValueList function.
enlarge_threshold
A number that when multiplied by the pattern length specifies the size of the sliding window.
norm_mconstraint
A number that represents the normalized mConstraint in the Sakoe-Chiba formula.
dtw_threshold
A number that represents the upper bound of the DTW score.

Usage

Run the Scan_DTW_Sakoe_Chiba_Constraint function to find sequences that are under the threshold based on the DTW score with a Sakoe-Chiba constraint in a time series using a sliding window. See Dynamic time warping.

Returns

A list of matches in a LIST data type that contains a SEARCHROW data type value for each match. See Scanning functions.