io.warp10.script.functions

Class DTW

java.lang.Object

io.warp10.script.NamedWarpScriptFunction

io.warp10.script.functions.DTW

All Implemented Interfaces:

WarpScriptStackFunction

public class DTW
extends NamedWarpScriptFunction
implements WarpScriptStackFunction

Perform Dynamic Time Warping pseudo-distance computation between two GTSs. It can be done on values, locations, elevations or timestamps.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	DTW.DTWDistance

Field Summary

Fields

Modifier and Type	Field and Description
static int	ELEVATIONS
static int	LOCATIONS
static int	TIMESTAMPS
static int	VALUES

Constructor Summary

Constructors

Constructor and Description
DTW(java.lang.String name, boolean normalize, boolean znormalize)

Method Summary

Modifier and Type	Method and Description
java.lang.Object	apply(WarpScriptStack stack)
static double	compute(double[][] values1, int offset1, int len1, double[][] values2, int offset2, int len2, int window, double threshold, DTW.DTWDistance distance) Compute the DTW pseudo-distance on two multi-dimensional data.
double	compute(GeoTimeSerie gts1, GeoTimeSerie gts2, int window, double threshold, int type, DTW.DTWDistance distance) Compute the DTW pseudo-distance on two GTS.
static double	euclidean(double[][] values1, int index1, double[][] values2, int index2)
static double	loxodromic(double[][] values1, int index1, double[][] values2, int index2)
static double	manhattan(double[][] values1, int index1, double[][] values2, int index2)
static double	orthodromic(double[][] values1, int index1, double[][] values2, int index2)
static double	squaredEuclidean(double[][] values1, int index1, double[][] values2, int index2)

Methods inherited from class io.warp10.script.NamedWarpScriptFunction

getName, refSnapshot, setName, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

TIMESTAMPS

public static final int TIMESTAMPS

See Also:

Constant Field Values

LOCATIONS

public static final int LOCATIONS

See Also:

Constant Field Values

ELEVATIONS

public static final int ELEVATIONS

See Also:

Constant Field Values

VALUES

public static final int VALUES

See Also:

Constant Field Values

Constructor Detail

DTW

public DTW(java.lang.String name,
           boolean normalize,
           boolean znormalize)

Method Detail

apply

public java.lang.Object apply(WarpScriptStack stack)
                       throws WarpScriptException

Specified by:

apply in interface WarpScriptStackFunction

Throws:

WarpScriptException

compute

public final double compute(GeoTimeSerie gts1,
                            GeoTimeSerie gts2,
                            int window,
                            double threshold,
                            int type,
                            DTW.DTWDistance distance)
                     throws WarpScriptException

Compute the DTW pseudo-distance on two GTS.

Parameters:

gts1 - One of the two GTSs to compare to the other.

gts2 - One of the two GTSs to compare to the other.

window - The window defining th maximum index difference when matching the GTSs. Integer.MAX_VALUE for no window constraint.

threshold - The maximum value of DTW. If the computed pseudo-distance is over this value, it is aborted and returns -1;

type - The characteristic of the GTSs to run the DTW on.

distance - The distance to use to compare GTS values.

Returns:

The pseudo-distance, -1 if the value would be over threshold.

Throws:

WarpScriptException - in case the DTW cannot be computed given the parameters.

compute

public static double compute(double[][] values1,
                             int offset1,
                             int len1,
                             double[][] values2,
                             int offset2,
                             int len2,
                             int window,
                             double threshold,
                             DTW.DTWDistance distance)
                      throws WarpScriptException

Compute the DTW pseudo-distance on two multi-dimensional data.

Parameters:

values1 - One of the two series to compare to the other. First index is the dimension, second is the element index. This way, less arrays are allocated because usually dimensions << number of elements.

offset1 - The start index from which to consider the data in values1.

len1 - Number of elements to consider in values1.

values2 - One of the two series to compare to the other. First index is the dimension, second is the element index.

offset2 - The start index from which to consider the data in values2.

len2 - Number of elements to consider in values2.

window - The window defining th maximum index difference when matching the data. Integer.MAX_VALUE for no window constraint.

threshold - The maximum value of DTW. If the computed pseudo-distance is over this value, it is aborted and returns -1;

distance - The distance to use to compare GTS values.

Returns:

The pseudo-distance, -1 if the value would be over threshold.

Throws:

WarpScriptException - in case the DTW cannot be computed given the parameters.

manhattan

public static double manhattan(double[][] values1,
                               int index1,
                               double[][] values2,
                               int index2)
                        throws WarpScriptException

Throws:

WarpScriptException

euclidean

public static double euclidean(double[][] values1,
                               int index1,
                               double[][] values2,
                               int index2)
                        throws WarpScriptException

Throws:

WarpScriptException

squaredEuclidean

public static double squaredEuclidean(double[][] values1,
                                      int index1,
                                      double[][] values2,
                                      int index2)
                               throws WarpScriptException

Throws:

WarpScriptException

loxodromic

public static double loxodromic(double[][] values1,
                                int index1,
                                double[][] values2,
                                int index2)
                         throws WarpScriptException

Throws:

WarpScriptException

orthodromic

public static double orthodromic(double[][] values1,
                                 int index1,
                                 double[][] values2,
                                 int index2)
                          throws WarpScriptException

Throws:

WarpScriptException