R: Ridge Estimation by Corona Method

corona {Rwave} | R Documentation

## Ridge Estimation by Corona Method

### Description

Estimate a (single) ridge from a time-frequency representation, using the corona method.

### Usage

    corona(tfrep, guess, tfspec=numeric(dim(tfrep)[2]), subrate=1,
    temprate=3, mu=1, lambda=2 * mu, iteration=1000000, seed=-7,
    stagnant=20000, costsub=1, plot=TRUE)

### Arguments

`tfrep` | Time-Frequency representation (real valued).
`guess` | Initial guess for the algorithm.
`tfspec` | Estimate for the contribution of the noise to modulus.
`subrate` | Subsampling rate for ridge estimation.
`temprate` | Initial value of temperature parameter.
`mu` | Coefficient of the ridge's second derivative in cost function.
`lambda` | Coefficient of the ridge's derivative in cost function.
`iteration` | Maximal number of moves.
`seed` | Initialization of random number generator.
`stagnant` | Maximum number of stationary iterations before stopping.
`costsub` | Subsampling of cost function in output.
`plot` | When set(default), some results will be shown on the display.

### Details

To accelerate convergence, it is useful to preprocess modulus before running annealing method. Such a preprocessing (smoothing and subsampling of modulus) is implemented in `corona`. The parameter subrate specifies the subsampling rate.

### Value

Returns the estimated ridge and the cost function.

`ridge` | 1D array (of same length as the signal) containing the ridge.
`cost` | 1D array containing the cost function.

### Warning

The returned cost may be a large array, which is time consuming. The argument costsub allows subsampling the cost function.

### References

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

### See Also

`icm`,`coronoid`,`snake`, `snakoid`.

[Package Rwave version 2.6-0 Index]