snakoid: Modified Snake Method

Description Usage Arguments Value References See Also

Description

Estimate a ridge from a time-frequency representation, using the modified snake method (modified cost function).

Usage

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snakoid(modulus, guessA, guessB, snakesize=length(guessB),
tfspec=numeric(dim(modulus)[2]), subrate=1, temprate=3, muA=1,
muB=muA, lambdaB=2 * muB, lambdaA=2 * muA, iteration=1000000,
seed=-7, costsub=1, stagnant=20000, plot=TRUE)

Arguments

modulus

Time-Frequency representation (real valued).

guessA

Initial guess for the algorithm (frequency variable).

guessB

Initial guess for the algorithm (time variable).

snakesize

The length of the first guess of time variable.

tfspec

Estimate for the contribution of srthe noise to modulus.

subrate

Subsampling rate for ridge estimation.

temprate

Initial value of temperature parameter.

muA

Coefficient of the ridge's derivative in cost function (frequency component).

muB

Coefficient of the ridge's derivative in cost function (time component).

lambdaB

Coefficient of the ridge's second derivative in cost function (time component).

lambdaA

Coefficient of the ridge's second derivative in cost function (frequency component).

iteration

Maximal number of moves.

seed

Initialization of random number generator.

costsub

Subsampling of cost function in output.

stagnant

Maximum number of stationary iterations before stopping.

plot

when set(default), some results will be displayed

Value

Returns a structure containing:

ridge

1D array (of same length as the signal) containing the ridge.

cost

1D array containing the cost function.

plot

when set(default), some results will be displayed.

References

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

See Also

corona, coronoid, icm, snake.


Rwave documentation built on May 2, 2019, 9:15 a.m.

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