dtwPlot {dtw} | R Documentation |
Methods for plotting dynamic time warp alignment objects returned
by dtw
.
## S3 method for class 'dtw': plot(x, type="alignment", ...) # an alias for dtw.plot dtwPlot(x, type="alignment", ...) dtwPlotAlignment(d, xlab="Query index", ylab="Reference index", ...) dtwPlotDensity(d, normalize=FALSE, xlab="Query index", ylab="Reference index", ...)
x,d |
dtw object, usually result of call to dtw |
xlab |
label for the query axis |
ylab |
label for the reference axis |
type |
alignment plot style |
normalize |
show per-step average cost instead of cumulative cost |
... |
additional arguments, passed to plotting functions |
dtwPlot
displays alignment contained in dtw
objects.
Various plotting styles are available, passing strings to the
type
argument (may be abbreviated):
alignment
d
twoway
threeway
density
For two-way plotting, see documentation for function
dtwPlotTwoWay
.
For three-way plotting, see documentation for function
dtwPlotThreeWay
.
If normalize
is TRUE
, the average cost per step
is plotted instead of the cumulative one. Step averaging depends on
the stepPattern
used.
Additional parameters are carried on to the plotting functions: use with care.
These functions are incompatible with mechanisms for
arranging plots on a device: par(mfrow)
, layout
and
split.screen
.
The density plot is more colorful than useful.
Toni Giorgino
dtwPlotTwoWay
for details on two-way plotting function.
dtwPlotThreeWay
for details on three-way plotting function.
## Same example as in dtw idx<-seq(0,6.28,len=100); query<-sin(idx)+runif(100)/10; reference<-cos(idx) alignment<-dtw(query,reference,keep=TRUE); ## A profile of the cumulative distance matrix ## Contour plot of the global cost dtwPlotDensity(alignment, main="Sine/cosine: symmetric alignment, no constraints") ###### ## ## A study of the "Itakura" parallelogram ## ## A widely held misconception is that the "Itakura parallelogram" (as ## described in the original article) is a global constraint. Instead, ## it arises from local slope restrictions. Anyway, an "itakuraWindow", ## is provided in this package. A comparison between the two follows. ## The local constraint: three sides of the parallelogram are seen dtw(query,reference,keep=TRUE,step=typeIIIc)->ita; dtwPlot(ita,type="density", main="Slope-limited asymmetric step (Itakura)") ## Symmetric step with global parallelogram-shaped constraint. Note how ## long (>2 steps) horizontal stretches are allowed within the window. dtw(query,reference,keep=TRUE,window=itakuraWindow)->ita; dtwPlot(ita,type="density", main="Symmetric step with Itakura parallelogram window")