andrews {andrews}

Andrews curves

Description

Andrews curves for visualization of multidimensional data. For colouring the curves see the details. For differences between andrews and andrews0 see the vignette("andrews"). With the same parameters called both functions should create the same plot. type==5 is a modification of type==3 and type==6 is a modification of type==4.

Usage

andrews(
  df,
  type = 1,
  clr = NULL,
  step = 100,
  ymax = 10,
  alpha = NULL,
  palcol = NULL,
  lwd = 1,
  lty = "solid",
  ...
)

Arguments

df

data frame or an R object that can be converted into a data frame with as.data.frame

type

type of curve

• 1: f(t)=x_1/\sqrt{2}+x_2\sin(t)+x_3\cos(t)+x_4\sin(2t)+x_5\cos(2t)+...

• 2: f(t)=x_1\sin(t)+x_2\cos(t)+x_3\sin(2t)+x_4\cos(2t)+...

• 3: f(t)=x_1\cos(t)+x_2\cos(\sqrt{2t})+x_3\cos(\sqrt{3t})+...

• 4: f(t)=0.5^{p/2}x_1+0.5^{(p-1)/2} x_2(\sin(t)+\cos(t))+0.5^{(p-2)/2} x_3(\sin(t)-\cos(t))+0.5^{(p-3)/2} x_4(\sin(2t)+\cos(2t))+0.5^{(p-4)/2}x_5(\sin(2t)-\cos(2t))+...) with p the number of variables

• 5: f(t)=x_1\cos(\sqrt{p_0} t)+x_2\cos(\sqrt{p_1}t)+x_3\cos(\sqrt{p_2}t)+... with p_0=1 and p_i the i-th prime number

• 6: f(t)=1/\sqrt{2}(x_1+x_2(\sin(t)+\cos(t))+x_3(\sin(t)-\cos(t))+x_4(\sin(2t)+\cos(2t))+x_5(\sin(2t)-\cos(2t))+...)

clr

number/name of column in the data frame for color of curves

step

smoothness of curves

ymax

maximum of y coordinate

alpha

semi-transparent color (0 < alpha < 1) which are supported only on some devices

palcol

a function which generates a set of colors, see details

lwd

line width, a positive number, defaulting to 1.

lty

line type, can either be specified as an integer (0=blank, 1=solid (default), 2=dashed, 3=dotted, 4=dotdash, 5=longdash, 6=twodash) or as one of the character strings "blank", "solid", "dashed", "dotted", "dotdash", "longdash", or "twodash", where "blank" uses ‘invisible lines’ (i.e., does not draw them).

...

further named parameters given to graphics::plot.default() except x, y, and type.

Details

If clr has length one then it is used as column number or column name for coloring the curves:

• If df[,clr] is numeric then palcol must be function which returns colors for values in the range ⁠\[0, 1\]⁠ using normalized variable. The default is function function(v) { hsv(0,1,v) }.

• Otherwise df[,clr] is converted to a factor and palcol must be a function which returns for each level a color. The parameter for palcol is the numbe of levels and the default is grDevices::rainbow(). If the length of clr is the number of rows of df then clr is interpreted as colors.

Andrews curves transform multidimensional data into curves. This package presents four types of curves.

Value

nothing

Author(s)

Sigbert Klinke [e-mail], Jaroslav Myslivec [e-mail]

References

• Andrews, D. F. (1972) Plots of High-Dimensional Data. Biometrics, vol. 28, no. 1, pp. 125-136.

• Khattree, R., Naik, D. N. (2002) Andrews Plots for Multivariate Data: Some New Suggestions and Applications. Journal of Statistical Planning and Inference, vol. 100, no. 2, pp. 411-425.

Examples

data(iris)
op <- par(mfrow=c(1,2))
andrews0(iris,clr=5,ymax=3)
andrews(iris,clr=5,ymax=3)
par(op)
andrews(iris,type=4,clr=5,ymax=NA)