aplpack (version 1.3.0)

skyline.hist: skyline.hist computes a skyline plot which is special histogram.

Description

The function skyline.hist draws several histograms in one plot. The resulting image may look like a skyline.

Usage

skyline.hist(x, n.class, n.hist = 1, main, ylab="density", 
                night = FALSE, col.bars = NA, col.border = 4, lwd.border = 2.5,
                n.shading = 6, lwd.shading = 2, col.shading = NA, lty.shading = 3,
                pcol.data = "green", cex.data = 0.3, pch.data = 16, col.data = 1,
                lwd.data = .2, permutation = FALSE, 
                xlab, xlim, ylim, new.plot=TRUE, bty="n", ...)

Arguments

x

one dimensional data set.

n.class

number of classes that should be used to find the width of the bars of the histogram(s).

n.hist

number of histograms that should be plotted.

main

used for call of title.

ylab

text for y axis.

night

If TRUE the background will be colored blue. If FALSE there will be no colored background. Otherwise night is used as background color.

col.bars

defines the color of the bars. If is.na(col.bars) and night==TRUE the bars will be colored gray.

col.border

color of the borders of the bars.

lwd.border

line width of the borders of the bars.

n.shading

number of vertical lines for filling the bars of the histograms.

lwd.shading

line width of the vertical lines for shading the bars.

col.shading

color for the vertical lines for shading. If NA heat colors are used.

lty.shading

line type for the vertical lines for shading.

pcol.data

color of data points.

cex.data

character size of plotting character.

pch.data

plotting character of data points.

lwd.data

line width for segments between data points.

col.data

color for segments between data points.

permutation

if not FALSE a permutation of the data set is erformed.

xlab

text for y axis.

xlim

range of x.

ylim

range of y.

new.plot

logical. If TRUE a new plot is constructed.

bty

box type, used by plot.

…

further graphical parameters passed to plot.

Value

The result of a call of hist is returned.

Details

skyline.hist computes several histograms and plots them one upon the other. The histograms differ in the positions of the first cells, but all cells have the same width. The parameters n.class and n.hist have the greatest effect on the design of the result. col.border allows to color the border of the rectangular boxes of the histogram bars. col.bars defines the fill color of the bars. n.shading defines the number of vertical lines of type lty.shading and width lwd.shading that are drawn within the boxes. Another feature of skyline.hist is to represent the data points. The data points of a cell are plotted according their x-values and their ranks (within the points of the cell). The resulting points are connected by line segments and you will see a time series running from bottom to top in each cell. The points and lines can be specified by pcol.data, cex.data, pch.data, lwd.data, col.data. To get rid of the original order of the data you can permutated them (permutation=1). The "skyline" of the plot may be similar to the skyline of a town and the vertical lines may look like small windows of buildings. In Young et. al. you find "shaded histograms". These histograms have triggered the idea of skyline.hist and the representation of a one dimensional data set by laying histograms on top of otheroverlied histograms.

References

F.W. Young, R.M. Valero-Mora, M. Friendly (2006): Visual Statistics. Wiley, p207--208.

See Also

hist, density

Examples

# NOT RUN {
  par(mfrow=c(3,3))
  for(n.c in c(2,4,8)){  # some values for n.class
    for(n.h in c(2,4,3)){  # some values for number of n.hist
        n.s <- 9         # value for number of vertical lines
        skyline.hist(co2, n.shading=n.s, n.hist=n.h ,n.class=n.c, 
                     night=n.h==3, col.border=n.h!=4)
    }
  }
  skyline.hist(x=rivers, n.class=4, n.hist=2, n.shading=0, main="rivers",
             cex.data=.5, lwd.data = .2, col.data = "green", pcol.data = "red",
             col.border=NA, night=FALSE, ylab="density")
  skyline.hist(x=rivers, n.class=4, n.hist=5, n.shading=0, main="rivers",
             cex.data=.5, lwd.data = 1, col.data = "green", pcol.data = "red",
             col.border=NA, night="blue" , ylab="density", col.bars =NA)
  skyline.hist(x=rivers, n.class=10, n.hist=2, n.shading=0, main="rivers",
             cex.data=.5, lwd.data = 1, col.data = "green", pcol.data = "red",
             col.border=NA, night=FALSE , ylab="density", col.bars = "lightblue")
  skyline.hist(x=rivers, n.class=10, n.hist=1, n.shading=0, main="rivers",
             cex.data=1, lwd.data = 0, col.data = "green", pcol.data = "red",
             col.border=NA, night=FALSE , ylab="density", col.bars = "lightblue" )
  skyline.hist(x=rivers, n.class=6, n.hist=1, n.shading=0, main="rivers",
             cex.data=0.1, lwd.data = 2, col.data = "red", pcol.data = "green",
             night="orange" , ylab="density", col.bars = "white", col.border=1 )
  skyline.hist(x=rivers, n.class=6, n.hist=1, n.shading=0, main="rivers",
             cex.data=0.1, lwd.data = 2, col.data = "red", pcol.data = "green",
             col.border=NA, night=FALSE , ylab="density", col.bars = "lightblue")
  skyline.hist(x=rivers, n.class=6, n.hist=1, n.shading=5, col.shading = "blue",
             main="rivers",
             cex.data=0.1, lwd.data = 1, col.data = "black", pcol.data = "green",
             col.border=NA, night=FALSE , ylab="density", col.bars = "green")
  skyline.hist(x=rivers, n.class=6, n.hist=3, n.shading=5, col.shading = "blue",
             main="rivers", col.bars = "green",
             cex.data=0.1, lwd.data = 1, col.data = "black", pcol.data = "green",
             col.border="white", night="magenta" , ylab="density")
  skyline.hist(x=rivers, n.class=6, n.hist=4, n.shading=5, col.shading = "blue",
             main="rivers",
             cex.data=0.8, lwd.data = 1, col.data = "blue", pcol.data = "red",
             col.border=NA, night=FALSE , ylab="density", col.bars = "green")
# }