grid.xaxis               package:grid               R Documentation

_D_r_a_w _a_n _X-_A_x_i_s

_D_e_s_c_r_i_p_t_i_o_n:

     These functions create and draw an x-axis.

_U_s_a_g_e:

     grid.xaxis(at = NULL, label = TRUE, main = TRUE,
                edits = NULL, name = NULL,
                gp = gpar(), draw = TRUE, vp = NULL)

     xaxisGrob(at = NULL, label = TRUE, main = TRUE,
               edits = NULL, name = NULL,
               gp = gpar(), vp = NULL)

_A_r_g_u_m_e_n_t_s:

      at: A numeric vector of x-value locations for the tick marks.

   label: A logical value indicating whether to draw the labels on the
          tick marks, or an expression or character vector which
          specify the labels to use.  If not logical, must be the same
          length as the 'at' argument.

    main: A logical value indicating whether to draw the axis at the
          bottom ('TRUE') or at the top ('FALSE') of the viewport.

   edits: A gEdit or gEditList containing edit operations to apply (to
          the children of the axis) when the axis is first created and
          during redrawing whenever 'at' is 'NULL'. 

    name: A character identifier. 

      gp: An object of class 'gpar', typically the output from a call
          to the function 'gpar'.  This is basically a list of
          graphical parameter settings.

    draw: A logical value indicating whether graphics output should be
          produced.

      vp: A Grid viewport obect (or 'NULL').

_D_e_t_a_i_l_s:

     Both functions create an xaxis grob (a graphical object describing
     an xaxis), but only 'grid.xaxis' draws the xaxis (and then only if
     'draw' is 'TRUE').

_V_a_l_u_e:

     An xaxis grob.  'grid.xaxis' returns the value invisibly.

_C_h_i_l_d_r_e_n:

     If the 'at' slot of an xaxis grob is not 'NULL' then the xaxis
     will have the following children:

     _m_a_j_o_r representing the line at the base of the tick marks.

     _t_i_c_k_s representing the tick marks.

     _l_a_b_e_l_s representing the tick labels.

     If the 'at' slot is 'NULL' then there are no children and ticks
     are drawn based on the current viewport scale.

_A_u_t_h_o_r(_s):

     Paul Murrell

_S_e_e _A_l_s_o:

     Grid, 'viewport', 'grid.yaxis'

