Coerce the scalogram matrix to a data frame — as.data.frame.fcwtr

Internally, the scalogram resulting from fcwt() is represented by a numeric matrix. This method coerces this matrix into a reasonable data frame. Note that this conversion has a significant run time cost.

Usage

# S3 method for class 'fcwtr_scalogram'
as.data.frame(x, ...)

Arguments

x: An object resulting from fcwt().
...: additional arguments to be passed to or from methods.

Value

A data.frame() object representing the scalogram data with four columns:

time_ind: An integer index uniquely identifying time slices.
time: The time difference to the first time slice in physical units. The time unit is the inverse of the frequency unit chosen by the user for the sample_freq argument of fcwt().
freq: The frequency in the same units as the sample_freq argument of fcwt().
value: The fCWT result for the particular time-frequency combination.

Examples

fcwt(
  sin((1:5000) * 2 * pi * 440 / 44100),
  sample_freq = 44100,
  n_freqs = 10
) |>
as.data.frame() |>
head()
#>   time_ind         time  freq        value
#> 1        0 0.000000e+00 22050           NA
#> 2        1 2.267574e-05 22050           NA
#> 3        2 4.535147e-05 22050 0.0025573892
#> 4        3 6.802721e-05 22050 0.0017304649
#> 5        4 9.070295e-05 22050 0.0011275189
#> 6        5 1.133787e-04 22050 0.0007753109