ggspectro {seewave}

2D-spectrogram of a time wave using ggplot2

Description

This function returns a ggplot object to draw a spectrogram with the package ggplot2. This is an alternative to spectro.

Usage

ggspectro(wave, f, tlab = "Time (s)",
flab = "Frequency (kHz)", alab = "Amplitude\n(dB)\n", ...)

Arguments

wave

an R object.

f

sampling frequency of wave (in Hz). Does not need to be specified if embedded in wave.

tlab

label of the time axis.

flab

label of the frequency axis.

alab

label of the amplitude axis.

...

other non-graphical arguments to be passed to spectro (wl, ovlp etc).

Details

This function return the fist layer (data and aesthetic mapping) of a ggplot2 plot.
See the example section to understand how to build a spectrogram and consult ggplot2 help to get what you exactly need.
There is no way to plot the oscillogram as spectro does.

Value

A ggpot layer.

Note

This function requires ggplot2 package.

Author(s)

Jerome Sueur

References

Wickham H (2009) – ggplot2: elegant graphics for data analysis. UseR! Springer.

See Also

spectro, spectro3D, dynspec

Examples

## Not run: 
require(ggplot2)
## first layer
v <- ggspectro(tico, ovlp=50)
summary(v)
## using geom_tile ##
v + geom_tile(aes(fill = amplitude)) + stat_contour()
## coordinates flip (interest?)
v + geom_tile(aes(fill = amplitude)) + stat_contour() + coord_flip()
## using stat_contour ##
# default (not nice at all)
v + stat_contour(geom="polygon", aes(fill=..level..))
# set up to 30 color levels with the argument bins
(vv <- v + stat_contour(geom="polygon", aes(fill=..level..), bins=30))
# change the limits of amplitude and NA values as transparent
vv + scale_fill_continuous(name="Amplitude\n(dB)\n", limits=c(-30,0), na.value="transparent")
# Black-and-white theme
(vv + scale_fill_continuous(name="Amplitude\n(dB)\n", limits=c(-30,0),
  na.value="transparent", low="white", high="black") + theme_bw())
# Other colour scale (close to spectro() default output)
v + stat_contour(geom="polygon", aes(fill=..level..), bins=30)
  + scale_fill_gradientn(name="Amplitude\n(dB)\n", limits=c(-30,0),
  na.value="transparent", colours = spectro.colors(30))

## End(Not run)