dBscale: dB colour scale for a spectrogram display

Description

This function displays a vertical or horizontal dB colour scale to be used with spectro plots.
Usage

dBscale(collevels, palette = spectro.colors, side = 4,
textlab = "Amplitude(dB)", cexlab = 0.75,
fontlab = 1, collab = "black", colaxis = "black",...)

collevels{a set of levels which are used to partition
      the amplitude range of the spectrogram (in dB).}
  palette{a color palette function to be used to assign colors in
      the plot, see note.}
  side{side of the axis.}
  textlab{text of the label.}  
  cexlab{character size of the label.}
  fontlab{font of the label.}
  collab{colour of the label.}
  colaxis{colour of the axis.}
  ...{other axis arguments.}    
[object Object],[object Object]
This function, based on filled.contour by Ross Ihaka,
is not supposed to be used by itself but as a legend of spectro.
Any colour palette can be used. In particular, it is possible
to use other palettes coming with
seewave: rev.gray.colors.1, rev.gray.colors.2,
rev.heat.colors, rev.terrain.colors, rev.topo.colors, 
rev.cm.colors corresponding to the reverse of heat.colors, 
terrain.colors, topo.colors, cm.colors.
spectro.
data(pellucens)
# place the scale on the left and not on the right as spectro() does
def.par <- par(no.readonly = TRUE)
layout(matrix(c(1, 2), nc = 2), widths = c(1, 5))
par(mar=c(5,3,4,2))
dBscale(collevels=seq(-30,0,1),side=2)
par(mar=c(5,4,4,2))
spectro(pellucens, f=22050,wl=512,scale=FALSE)
par(def.par)
# place the scale on the top and not on the right as spectro() does
def.par <- par(no.readonly = TRUE)
layout(matrix(c(0,1,2,2), nc = 2, byrow=TRUE),widths=c(1,2),heights=(c(1,5.5)))
par(mar=c(0.5,3,4,2))
dBscale(collevels=seq(-30,0,1), textlab = "",side=3)
mtext("Amplitude (dB)",side=2,line = 1,at=0.6,cex=0.75)
par(mar=c(5,4,0.5,2))
spectro(pellucens, f=22050,wl=512,scale=FALSE)
par(def.par)
dplot
ts
Description

Usage

Arguments
