Plotting of dynamic time warp results: annotated warping function
Display the query and reference time series and their warping curve, arranged for visual inspection.
dtwPlotThreeWay(d,xts=NULL,yts=NULL, type.align="l",type.ts="l", match.indices=NULL, margin=4, inner.margin=0.2, title.margin=1.5, xlab="Query index",ylab="Reference index",main="Timeseries alignment", ... )
- an alignment result, object of class
- query vector
- reference vector
- label for the query axis
- label for the reference axis
- main title
- line style for warping curve plot
- line style for timeseries plot
- indices for which to draw a visual guide
- outer figure margin
- inner figure margin
- space on the top of figure
- additional arguments, used for the warping curve
The query time series is plotted in the bottom panel, with indices growing rightwards and values upwards. Reference is in the left panel, indices growing upwards and values leftwards. The warping curve panel matches indices, and therefore element (1,1) will be at the lower left, (N,M) at the upper right.
match.indices is used to draw a visual guide to
matches; if a vector is given, guides are drawn for the corresponding
indices in the warping curve (match lines). If integer, it is used as
the number of guides to be plotted. The corresponding style is
customized via the
yts are not supplied, they will be recovered
d, as long as it was created with the two-argument call of
keep.internals=T. Only single-variate
time series can be plotted.
The function is incompatible with mechanisms for
arranging plots on a device:
split.screen. Appearance of the match lines and timeseries
currently can not be customized.
## A noisy sine wave as query ## A cosine is for reference; sin and cos are offset by 25 samples idx<-seq(0,6.28,len=100); query<-sin(idx)+runif(100)/10; reference<-cos(idx) dtw(query,reference,keep=TRUE)->alignment; ## Beware of the reference's y axis, may be confusing ## Equivalent to plot(alignment,type="three"); dtwPlotThreeWay(alignment); ## Highlight matches of chosen QUERY indices. We will do some index ## arithmetics to recover the corresponding indices along the warping ## curve hq <- (0:8)/8 hq <- round(hq*100) # indices in query for pi/4 .. 7/4 pi hw <- (alignment$index1 %in% hq) # where are they on the w. curve? hi <- (1:length(alignment$index1))[hw]; # get the indices of TRUE elems dtwPlotThreeWay(alignment,match.indices=hi);