eqscplot                package:MASS                R Documentation

_P_l_o_t_s _w_i_t_h _G_e_o_m_e_t_r_i_c_a_l_l_y _E_q_u_a_l _S_c_a_l_e_s

_D_e_s_c_r_i_p_t_i_o_n:

     Version of a scatterplot with scales chosen to be equal on both
     axes, that is 1cm represents the same units on each

_U_s_a_g_e:

     eqscplot(x, y, ratio = 1, tol = 0.04, uin, ...)

_A_r_g_u_m_e_n_t_s:

       x: vector of x values, or a 2-column matrix, or a list with
          components 'x' and 'y' 

       y: vector of y values 

   ratio: desired ratio of units on the axes.  Units on the y axis are
          drawn at 'ratio' times the size of units on the x axis. 
          Ignored if 'uin' is specified and of length 2. 

     tol: proportion of white space at the margins of plot 

     uin: desired values for the units-per-inch parameter. If of length
          1, the desired units per inch on the x axis. 

     ...: further arguments for 'plot' and graphical parameters.  Note
          that 'par(xaxs="i", yaxs="i")' is enforced, and 'xlim' and
          'ylim' will be adjusted accordingly. 

_D_e_t_a_i_l_s:

     Limits for the x and y axes are chosen so that they include the
     data.  One of the sets of limits is then stretched from the
     midpoint to make the units in the ratio given by 'ratio'. Finally
     both are stretched by '1 + tol' to move points away from the axes,
     and the points plotted.

_V_a_l_u_e:

     invisibly, the values of 'uin' used for the plot.

_S_i_d_e _E_f_f_e_c_t_s:

     performs the plot.

_N_o_t_e:

     Arguments 'ratio' and 'uin' were suggested by Bill Dunlap.

_R_e_f_e_r_e_n_c_e_s:

     Venables, W. N. and Ripley, B. D. (2002) _Modern Applied
     Statistics with S._ Fourth edition.  Springer.

_S_e_e _A_l_s_o:

     'plot', 'par'

