R: Ridge Chaining Procedure

cfamily {Rwave} | R Documentation

## Ridge Chaining Procedure

### Description

Chains the ridge estimates produced by the function `crc`.

### Usage

    cfamily(ccridge, bstep=1, nbchain=100, ptile=0.05)

### Arguments

`ccridge` | unchained ridge set as the output of the function `crc`
`bstep` | maximal length for a gap in a ridge.
`nbchain` | maximal number of chains produced by the function.
`ptile` | relative threshold for the ridges.

### Details

`crc` returns a measure in time-frequency (or time-scale) space. `cfamily` turns it into a series of one-dimensional objects (ridges). The measure is first thresholded, with a relative threshold value set to the input parameter ptile. During the chaining procedure, gaps within a given ridge are allowed and filled in. The maximal length of such gaps is the input parameter bstep.

### Value

Returns the results of the chaining algorithm

`ordered map` | image containing the ridges (displayed with different colors)
`chain` | 2D array containing the chained ridges, according to the chain data structure chain[,1]: first point of the ridge chain[,2]: length of the chain chain[,3:(chain[,2]+2)]: values of the ridge
`nbchain` | number of chains produced by the algorithm

### References

See discussion in text of “Practical Time-Frequency Analysis”.

### See Also

`crc` for the ridge estimation, and `crcrec`, `gcrcrec` and `scrcrec` for corresponding reconstruction functions.

### Examples

    ## Not run:
       data(HOWAREYOU)
     plot.ts(HOWAREYOU)

    cgtHOWAREYOU <- cgt(HOWAREYOU,70,0.01,100)

    clHOWAREYOU <- crc(Mod(cgtHOWAREYOU),nbclimb=1000)

    cfHOWAREYOU <- cfamily(clHOWAREYOU,ptile=0.001)
    image(cfHOWAREYOU$ordered > 0)

    ## End(Not run)

[Package Rwave version 2.5-0 Index]