

abline {base}                                R Documentation

_A_d_d _a _S_t_r_a_i_g_h_t _L_i_n_e _t_o _a _P_l_o_t

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

     This function adds one or more straight lines through
     the current plot.

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

     abline(a, b, ...)
     abline(h=, ...)
     abline(v=, ...)
     abline(untf=, ...)
     abline(coef=, ...)
     abline(reg=, ...)

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

     The first form specifies the line in intercept/slope
     form (alternatively `a' can be specified on its own and
     is taken to contain the slope and intercept in vector
     form).

     The `h=' and `v=' forms draw horizontal and vertical
     lines at the specified coordinates.

     The `coef' form specifies the line by a vector contain-
     ing the slope and intercept.  `reg' is a regression
     object which contains `reg$coef'.  If it is of length 1
     then the value is taken to be the slope of a line
     through the origin, otherwise, the first 2 values are
     taken to be the intercept and slope.

     If `untf' is true, and one or both axes are log-trans-
     formed, then a curve is drawn corresponding to a line
     in original coordinates, otherwise a line is drawn in
     the transformed coordinate system. The `h' and `v'
     parameters alway refer to original coordinates.

     The graphical parameters `col' and `lty' can be speci-
     fied as arguments to `abline'; see `par' for details.

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

     `lines' and `segments' for connected and arbitrary
     lines given by their endpoints.  `par'.

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

     data(cars)
     z <- lm(dist ~ speed, data = cars)
     plot(cars)
     abline(z)

