bagplot               package:aplpack               R Documentation

_b_a_g_p_l_o_t, _a _b_i_v_a_r_i_a_t_e _b_o_x_p_l_o_t

_D_e_s_c_r_i_p_t_i_o_n:

     'compute.bagplot()' computes an object describing a bagplot of a
     bivariate data set.  'plot.bagplot()' plots a bagplot object. 
     'bagplot()' computes and plots a bagplot.

_U_s_a_g_e:

     bagplot(x, y, factor = 3, na.rm = FALSE, approx.limit = 300,  
            show.outlier = TRUE, show.whiskers = TRUE, 
            show.looppoints = TRUE, show.bagpoints = TRUE,
            show.loophull = TRUE, show.baghull = TRUE, 
            create.plot = TRUE, add = FALSE, pch = 16, cex = 0.4, 
            dkmethod = 2, precision = 1, verbose = FALSE, 
            debug.plots = "no",   col.loophull="#aaccff", 
            col.looppoints="#3355ff", col.baghull="#7799ff", 
            col.bagpoints="#000088", transparency=FALSE, ...
     )
     compute.bagplot(x, y, factor = 3, na.rm = FALSE, approx.limit = 300, 
            dkmethod=2,precision=1,verbose=FALSE,debug.plots="no")
     plot.bagplot(x,  
            show.outlier = TRUE, show.whiskers = TRUE, 
            show.looppoints = TRUE, show.bagpoints = TRUE,
            show.loophull = TRUE, show.baghull = TRUE, 
            add = FALSE, pch = 16, cex = 0.4, verbose = FALSE, 
            col.loophull="#aaccff", col.looppoints="#3355ff", 
            col.baghull="#7799ff", col.bagpoints="#000088", 
            transparency=FALSE,...)

_A_r_g_u_m_e_n_t_s:

       x: x values of a data set;  in 'bagplot': an object of class
          'bagplot' computed by 'compute.bagplot' 

       y: y values of the data set 

  factor: factor defining the loop 

   na.rm: if TRUE 'NA' values are removed otherwise exchanged by mean

approx.limit: if the number of data points exceeds  'approx.limit' a
          sample is used to compute  some of the quantities; default:
          300 

show.outlier: if TRUE outlier are shown 

show.whiskers: if TRUE whiskers are shown 

show.looppoints: if TRUE loop points are plottet 

show.bagpoints: if TRUE bag points are plottet 

show.loophull: if TRUE the loop is plotted 

show.baghull: if TRUE the bag is plotted 

create.plot: if FALSE no plot is created 

     add: if TRUE the bagplot is added to an existing plot 

     pch: sets the plotting character 

     cex: sets characters size

dkmethod: 1 or 2, there are two method of   approximating the bag,
          method 1 is very rough 

precision: precision of approximation, default: 1 

 verbose: automatic commenting of calculations  

debug.plots: if TRUE additional plots describing  intermediate results
          are constructed 

col.loophull: color of loop hull 

col.looppoints: color of the points of the loop 

col.baghull: color of bag hull 

col.bagpoints: color of the points of the bag 

transparency: see section details 

     ...: additional graphical parameters 

_D_e_t_a_i_l_s:

     A bagplot is a bivariate generalization of the well known boxplot.
     It has been proposed by Rousseeuw, Ruts, and Tukey. In the
     bivariate case the box of the boxplot changes to a  convex
     polygon, the bag of bagplot. In the bag are 50 percent of all
     points. The fence separates points within the fence from  points
     outside. It is computed by increasing the the bag. The loop is
     defined as the convex hull containing  all points inside the
     fence.  If all points are on a straight line you get a classical
     boxplot. 'bagplot()' plots bagplots that are very similar  to the
     one described in Rousseeuw et al.  Remarks: The two dimensional
     median is approximated. For large data sets the error will be very
     small. On the other hand it is not very wise to make a (graphical)
      summary of e.g. 10 bivariate data points. In case you want to
     plot multiple (overlapping) bagplots,  you may want plots that are
     semi-transparent. For this  you can use the 'transparency' flag. 
     If 'transparency==TRUE' the alpha layer is set to '99' (hex). This
     causes the bagplots to appear semi-transparent,  but ONLY if the
     output device is PDF and opened using: 'pdf(file="filename.pdf",
     version="1.4")'.  For this reason, the default is
     'transparency==FALSE'.  This feature as well as the arguments to
     specify different colors has been proposed by Wouter Meuleman.

_V_a_l_u_e:

     'compute.bagplot' returns an object of class 'bagplot' that could
     be plotted by  'plot.bagplot()'.

_N_o_t_e:

     Version of bagplot: 08/2007

_A_u_t_h_o_r(_s):

     Peter Wolf

_R_e_f_e_r_e_n_c_e_s:

     P. J. Rousseeuw, I. Ruts, J. W. Tukey (1999): The bagplot: a
     bivariate boxplot, The American Statistician, vol. 53, no. 4,
     382-387

_S_e_e _A_l_s_o:

     'boxplot'

_E_x_a_m_p_l_e_s:

       # example: 100 random points and one outlier
       dat<-cbind(rnorm(100)+100,rnorm(100)+300)
       dat<-rbind(dat,c(105,295))
       bagplot(dat,factor=2.5,create.plot=TRUE,approx.limit=300,
          show.outlier=TRUE,show.looppoints=TRUE,
          show.bagpoints=TRUE,dkmethod=2,
          show.whiskers=TRUE,show.loophull=TRUE,
          show.baghull=TRUE,verbose=FALSE)
       # example of Rousseeuw et al., see R-package rpart
       cardata <- structure(as.integer( c(2560,2345,1845,2260,2440,
        2285, 2275, 2350, 2295, 1900, 2390, 2075, 2330, 3320, 2885,
        3310, 2695, 2170, 2710, 2775, 2840, 2485, 2670, 2640, 2655,
        3065, 2750, 2920, 2780, 2745, 3110, 2920, 2645, 2575, 2935,
        2920, 2985, 3265, 2880, 2975, 3450, 3145, 3190, 3610, 2885,
        3480, 3200, 2765, 3220, 3480, 3325, 3855, 3850, 3195, 3735,
        3665, 3735, 3415, 3185, 3690, 97, 114, 81, 91, 113, 97, 97,
        98, 109, 73, 97, 89, 109, 305, 153, 302, 133, 97, 125, 146,
        107, 109, 121, 151, 133, 181, 141, 132, 133, 122, 181, 146,
        151, 116, 135, 122, 141, 163, 151, 153, 202, 180, 182, 232,
        143, 180, 180, 151, 189, 180, 231, 305, 302, 151, 202, 182,
        181, 143, 146, 146)), .Dim = as.integer(c(60, 2)), 
        .Dimnames = list(NULL, c("Weight", "Disp.")))
       bagplot(cardata,factor=3,show.baghull=TRUE,
         show.loophull=TRUE,precision=1,dkmethod=2)
       title("car data Chambers/Hastie 1992")
       # points of y=x*x
       bagplot(x=1:30,y=(1:30)^2,verbose=FALSE,dkmethod=2)
       # one dimensional subspace
       bagplot(x=1:100,y=1:100)

