dtwPlotTwoWay

0th

Percentile

Plotting of dynamic time warp results: pointwise comparison

Display the query and reference time series and their alignment, arranged for visual inspection.

Keywords
hplot
Usage
dtwPlotTwoWay(d,xts=NULL,yts=NULL, offset=0, ts.type="l",pch=21, match.indices=NULL, match.col="gray70", match.lty=3, xlab="Index", ylab="Query value", ... )
Arguments
d
an alignment result, object of class dtw
xts
query vector
yts
reference vector
xlab,ylab
axis labels
offset
displacement between the timeseries, summed to reference
match.col, match.lty
color and line type of the match guide lines
match.indices
indices for which to draw a visual guide
ts.type,pch
graphical parameters for timeseries plotting, passed to matplot
...
additional arguments, passed to matplot
Details


The two vectors are displayed via the matplot functions; their appearance can be customized via the type and pch arguments (constants or vectors of two elements). If offset is set, the reference is shifted vertically by the given amount; this will be reflected by the right-hand axis.
Argument 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 match.col and match.lty arguments.
If xts and yts are not supplied, they will be recovered from d, as long as it was created with the two-argument call of dtw with keep.internals=T. Only single-variate time series can be plotted this way.

Note

When offset is set values on the left axis only apply to the query.

Warning

The function is incompatible with mechanisms for arranging plots on a device: par(mfrow), layout and split.screen.

See Also

dtwPlot for other dtw plotting functions, matplot for graphical parameters.

Aliases
  • dtwPlotTwoWay
Examples

## 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,step=asymmetricP1,keep=TRUE)->alignment;


## Equivalent to plot(alignment,type="two");
dtwPlotTwoWay(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


## Beware of the reference's y axis, may be confusing
plot(alignment,offset=-2,type="two", lwd=3, match.col="grey50",
     match.indices=hi,main="Match lines shown every pi/4 on query");

legend("topright",c("Query","Reference (rt. axis)"), pch=21, col=1:6)



Documentation reproduced from package dtw, version 1.18-1, License: GPL (>= 2)

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