R: Display the cumulative cost density with the warping path...

dtwPlotDensity {dtw} | R Documentation

## Display the cumulative cost density with the warping path overimposed

### Description

The plot is based on the cumulative cost matrix. It displays the optimal alignment as a "ridge" in the global cost landscape.

### Usage

    dtwPlotDensity(
      d,
      normalize = FALSE,
      xlab = "Query index",
      ylab = "Reference index",
      ...
    )

### Arguments

`d` | an alignment result, object of class `dtw`
`normalize` | show per-step average cost instead of cumulative cost
`xlab` | label for the query axis
`ylab` | label for the reference axis
`...` | additional parameters forwarded to plotting functions

### Details

The alignment must have been constructed with the `keep.internals=TRUE` parameter set.

If `normalize` is `TRUE`, the average cost per step is plotted instead of the cumulative one. Step averaging depends on the `stepPattern()` used.

### See Also

Other plot: `dtwPlotThreeWay()`, `dtwPlotTwoWay()`, `dtwPlot()`

### Examples

    ## 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
    idx<-seq(0,6.28,len=100);
    query<-sin(idx)+runif(100)/10;
    reference<-cos(idx)

    ita <- dtw(query,reference,keep=TRUE,step=typeIIIc)
    dtwPlotDensity(ita, 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;
    dtwPlotDensity(ita,
            main="Symmetric step with Itakura parallelogram window")

[Package dtw version 1.22-3 Index]