morsecodes               package:xgobi               R Documentation

_R_o_t_h_k_o_p_f _M_o_r_s_e _C_o_d_e _D_a_t_a

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

     A standard data set for Multidimensional Scaling (MDS) obtained by
     Rothkopf based on the confusion rates observed by exposing
     subjects to pairs of morse codes.

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

     data(morsecodes)

_F_o_r_m_a_t:

     9 data sets used for analyzing the data in XGvis and XGobi.

       `morsecodes.raw'         36 x 36 raw data of confusion rates
       `morsecodes.dist'        36 x 36 dissimilarity matrix
       `morsecodes.pos'         36 x 10 initial configuration
       `morsecodes.colors'      36 point colors
       `morsecodes.glyphs'      36 point glyphs
       `morsecodes.lines'       33 lines
       `morsecodes.linecolors'  33 line colors
       `morsecodes.row'         36 x 2 matrix of (letter, morsecode)
       `morsecodes.col'         10 column names of the initial configuration

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

     The raw data from the XGvis directory may be read as 
     `mc.raw <-
     as.matrix(read.table("....xgobi/data_xgvis/morsecodes.raw"))' 
     `dimnames(mc.raw) <- NULL; storage.mode(mc.raw) <- "integer"' 
     `morsecodes.raw <- mc.raw'.

     The `*.dist' matrix is produced from the raw data by 
     `mc.sim <- (mc.raw + t(mc.raw))/2 ;  ds <- diag(mc.sim)' 
     `morsecodes.dist <- rep(ds,36) + rep(ds,rep(36,36)) - 2*mc.sim', 
     i.e., d[i,j] := s[i,i] + s[j,j] - 2 * s[i,j].

_S_o_u_r_c_e:

     Contained in the `data_xgvis' subdirectory of the XGobi and XGvis
     source bundle, available via <URL:
     http://www.research.att.com/areas/stat/xgobi/index.html#download>.

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

     A. Buja, D. F. Swayne, M. Littman, & N. Dean (1998). XGvis:
     Interactive Data Visualization with Multidimensional Scaling.
     <URL: http://www.research.att.com/areas/stat/xgobi/xgvis98.ps.gz>.

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

     data(morsecodes)
     ls.str(pat="^morsecode")
     morsecodes.row # remember what you learned in...
     ## real row names
     (mc.row <- paste(morsecodes.row[,1], morsecodes.row[,2]))[1:8]

     image(1:36, 1:36, morsecodes.raw, main="`morsecodes' raw confusion rates")
     text(1:36,1:36, morsecodes.row[,1])

     ##--> help(xgvis) for running multidimensional scaling (MDS) and XGobi on these

