

xgvis(xgobi)                                 R Documentation

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_d_i_s_p_l_a_y

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

     an interactive multidimensional scaling (MDS) program
     that consists of a control panel to manipulate the
     parameters of the MDS stress function and an xgobi win-
     dow for data display.  It can be used either for visu-
     alization of dissimilarity data, for dimension reduc-
     tion, or for graph layout.  Graph layout is usually
     done in 2D, but xgvis allows layouts in arbitrary
     dimensions, 3D being the default.  It permits missing
     values, which can be used to implement multidimensional
     unfolding.

_U_s_a_g_e_:

     xgvis(matrx,
     edges=NULL, pos=NULL, rowlab=NULL, colors=NULL, glyphs=NULL,
     erase=NULL, lines=NULL, linecolors=NULL, resources=NULL,
     display=NULL)

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

   matrx: An nxn distance matrix

   edges: Line segments: specifications for the pattern of
          line segments which connect pairs of points.  The
          file must contain at least two numbers per line.
          The first two numbers represent the row numbers of
          the two points that should be connected.  (This is
          exactly like the structure of a fname.lines file
          in xgobi.)  In addition, if a third number is pre-
          sent, it is taken to be an edge weight.  If this
          line is present and the distance matrix is absent,
          then the distance matrix is computed from it, with
          each edge representing a distance of one.

     pos: Starting positions:  an n x p matrix, with entries
          separated by white space and one row per line.  If
          this file is present and a distance file is
          absent, the distance matrix is computed from it.

  rowlab: Optional character vector of row labels; the
          default is `dimnames(matrx)[[1]]'.  If no default
          exists, xgobi constructs its own defaults.

  colors: Optional character vector, used to supply initial
          point colors to be used; the default is that all
          points are the same color.

  glyphs: Optional integer vector, used to supply glyphs to
          be used on startup; the default is that all points
          are drawn with the same glyph.

   erase: Optional integer vector of length equal to the
          number of rows in the data and composed of 1s and
          0s.  A 1 in position i specifies that point i
          should be erased.  The default is a vector of 0s.

   lines: Optional integer matrix, n by 2, which specifies
          by row number pairs of points to be connected by
          line segments.  If this file is present, then the
          edges file is used to create the distance matrix
          but the lines file is used to draw the edges.

linecolors: Optional integer vector, of length n where n is
          the number of lines specified by the 'lines' argu-
          ment.  It is used to supply line colors to be used
          on startup; the default is for all the lines to be
          drawn in the standard foreground color.

resources: Optional character vector created by clicking on
          the "Save Resources" button in XGobi (if this
          XGvis was initiated during an S session).

 display: Optional character string, identifying the monitor
          on which to display the xgvis window.  The default
          is `"machine:0.0"' where `machine' is the name of
          the user's workstation.  See documentation for X.

_V_a_l_u_e_:

     The UNIX `status' upon completion, i.e. `0' if ok.

_S_i_d_e _E_f_f_e_c_t_s_:

     The xgvis S function executes a call to the C program
     of the same name, and returns control of the S shell to
     the user.

_C_O_N_T_A_C_T_:

     D. F. Swayne dfs@research.att.com

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

     http://www.research.att.com/areas/stat/xgobi/
     http://www.public.iastate.edu/~dicook/

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

     ## The following examples use sample data files from the data_xgvis
     ## directory in the xgobi and xgvis distribution directory.

     data(morsecodes)
     xgvis(dmat = morsecodes.dist,
           pos = morsecodes.pos,
           row = morsecodes.row,
           colors = morsecodes.colors,
           glyphs = morsecodes.glyphs,
           lines = morsecodes.lines,
           linecolors = morsecodes.linecolors)

     data(perm4)
     xgvis(edges = perm4.edges)
     xgvis(edges = perm4.edges,
           linecolors = perm4.linecolors)

