emuR (version 2.4.0)

fapply: Function that applies a function to an EMU spectral object

Description

Applies a function to an EMU spectral object.

Usage

fapply(specdata, fun, ..., power = FALSE, powcoeffs = c(10, 10))

Value

If the output has the same dimensions has the input, then an object of the same dimensionality and class is returned. Otherwise it may be a vector or matrix depending on the function that is applied. ...

Arguments

specdata

A matrix or trackdata object of class spectral

fun

A function to be applied.

...

Optional arguments to fun

power

A single element logical vector. If TRUE, convert specdata to power values i.e. apply the function to a * specdata \(\mbox{\textasciicircum}\)b or a * specdata$data \(\mbox{\textasciicircum}\)b where a and b powcoeffs defined below.

powcoeffs

A 2 element numeric vector for converting dB values to power values. Defaults to a = 10 and b = 10. See power.

Warning

The function can be very slow if applied to a large trackdata object. In this case, it may be faster to use a for-loop with the desired function around $data

Author

Jonathan Harrington

Details

fapply performs a similar operation to apply except that it is specifically designed for handling EMU spectral objects.

See Also

apply by.trackdata

Examples

# mean value per spectrum, input is a spectral matrix
m <- fapply(vowlax.dft.5, sapply, FUN=mean)
# as above but after converting dB to powers before
# applying the function
m <- fapply(vowlax.dft.5, sapply, FUN=mean, power=TRUE)
# spectral range
r <- fapply(vowlax.dft.5, range)
# spectral moments applied to a trackdata object
# m is a four-dimensional trackdata object
m <- fapply(fric.dft, moments)
# 1st 3 DCT coefficients calculated in a spectral matrix
# d is a 3-columned matrix
d <- fapply(vowlax.dft.5, dct, 3)
# dct-smooth with 10 coefficients. d2 is spectral matrix
d2 <- fapply(vowlax.dft.5, dct, 10, TRUE)
# dct-smooth a trackdata object with 10 coefficients
d3 <- fapply(fric.dft[1:4,], dct, 10, TRUE)