warpArea {dtw} | R Documentation |
Compute Warping Path Area
Description
Compute the area between the warping function and the diagonal (no-warping) path, in unit steps.
Usage
warpArea(d)
Arguments
d |
an object of class |
Details
Above- and below- diagonal unit areas all count plus one (they do not
cancel with each other). The "diagonal" goes from one corner to the other
of the possibly rectangular cost matrix, therefore having a slope of
M/N
, not 1, as in slantedBandWindow()
.
The computation is approximate: points having multiple correspondences are averaged, and points without a match are interpolated. Therefore, the area can be fractionary.
Value
The area, not normalized by path length or else.
Note
There could be alternative definitions to the area, including considering the envelope of the path.
Author(s)
Toni Giorgino
Examples
ds<-dtw(1:4,1:8);
plot(ds);lines(seq(1,8,len=4),col="red");
warpArea(ds)
## Result: 6
## index 2 is 2 while diag is 3.3 (+1.3)
## 3 3 5.7 (+2.7)
## 4 4:8 (avg to 6) 8 (+2 )
## --------
## 6
[Package dtw version 1.23-1 Index]