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Compare sounds with dynamic spectrograms

Source: R/dynaspec.R
ds_compare.Rd

ds_compare() shows two or more sounds one on top of the other and plays them in sequence, from top to bottom. Layers are added with +, as in dynaspec(), and are applied to all sounds.

Usage

ds_compare(..., flim = NULL, tlim = NULL, gap = 0.5, same.scale = TRUE)

Arguments

...

The sounds (at least two), in the order they are shown and played: objects of class 'Wave', paths to '.wav' or '.mp3' files, or dynaspec() objects, or a single list of them. Use dynaspec() objects for settings or layers of a single sound (e.g. its own ds_annotations(), ds_captions() or time range).

flim

Numeric vector of length 2 with the frequency limits (in kHz) of all sounds, as in dynaspec(). Default is NULL: the limits set in dynaspec() objects; limits set for only some sounds are used for all of them, if they are the same. Sounds with different sampling rates are shown up to the lowest Nyquist frequency, so all use the same frequency axis (unless they have different limits set in dynaspec() objects).

tlim

Numeric vector of length 1 or 2 with the time range (in s) of all sounds, as in dynaspec(). Default is NULL (the whole sounds, or the time range set in dynaspec() objects).

gap

Numeric vector of length 1 with the silence (in s) between consecutive sounds. Default is 0.5.

same.scale

Logical: use the same time scale for all sounds, so a second takes the same width in all of them? Static spectrograms leave empty room to the right of shorter sounds, and paged spectrograms without 't.display' use the duration of the longest sound as the duration of their pages (scrolling spectrograms and paged spectrograms with 't.display' always have the same scale). FALSE fits each sound to the width of the figure. Default is TRUE.

Value

An object of class 'dynaspec_compare' (also of class 'dynaspec'), which is shown and saved as any dynaspec() object, with layers added with +.

Details

All styles, panels, themes and output formats of dynaspec() objects can be used, and all sounds must use the same style:

  • Web pages have a single set of controls below the sounds. Speed, pitch, volume and zoom apply to all sounds, the time readout shows the number of the sound being played and its time, the seek bar spans all sounds, the loop button repeats the sequence and the download button saves all sounds (browsers may ask for permission to download several files). Clicking on a spectrogram plays that sound from that point, and then the following ones (the sequence ends after the last sound).

  • Videos ('.mp4', requires 'ffmpeg') stack the videos of the sounds: each sound keeps its first frame until it is played, and its last frame afterwards.

  • Still images ('.png') stack the images of the sounds (paged spectrograms: one image per page, stacking the pages with the same number).

Annotations and captions added to a comparison are applied to all sounds, with times referring to each sound. To add them to a single sound, add them to its dynaspec() object. Layers added to a comparison replace (or are combined with) those of the dynaspec() objects, as in any dynaspec() object.

Amplitudes are scaled within each sound (as in dynaspec()), so the colors of the spectrograms and the height of the oscillograms do not compare the amplitude of the sounds.

See also

dynaspec(), save_dynaspec()

Examples

data(female_barn_swallow, male_barn_swallow)

x <- ds_compare(female_barn_swallow, male_barn_swallow, flim = c(0, 10)) +
  ds_spectrogram(wl = 512, collevels = seq(-50, 0, 1))

save_dynaspec(x, file.path(tempdir(), "swallows.html"), play = FALSE)

if (FALSE) { # \dontrun{
# show it
x

# other panels, styles and themes, as in dynaspec()
x + ds_oscillogram() + ds_theme_mako()
x + ds_scrolling(t.display = 1)
x + ds_paged(t.display = 1) + ds_player(buttons = c("progress", "time", "loop"))

# more than two sounds
data(scythebill)
ds_compare(female_barn_swallow, male_barn_swallow, scythebill) +
  ds_spectrogram(wl = 512)

# video (requires ffmpeg)
save_dynaspec(x, file.path(tempdir(), "swallows.mp4"))

# layers of a single sound
st <- data.frame(start = 0.5, end = 1, labels = "A")
a <- dynaspec(female_barn_swallow) + ds_annotations(st, labels = "labels")
ds_compare(a, male_barn_swallow, flim = c(0, 10), gap = 1) + ds_spectrogram(wl = 512)
} # }