ellipse               package:ellipse               R Documentation

_M_a_k_e _a_n _e_l_l_i_p_s_e

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

     This function returns an ellipse or other outline of a confidence
     region for two parameters.   This is a generic function. Functions
     with names beginning in `ellipse.' will be methods for this
     function. `lm', `nls', `profile', `profile.nls'

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

     ellipse(x, ...)

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

       x: An S object. 

     ...: Each of the specialized types uses different optional
          parameters. 

_V_a_l_u_e:

     A matrix is returned with two columns outlining an ellipse or a
     confidence region.

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

     ellipse.arima, plotcorr

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

     # Plot an ellipse corresponding to a 95% probability region for a
     # bivariate normal distribution with mean 0, unit variances and 
     # correlation 0.8.
     plot(ellipse(0.8),type='l')
     # Plot the joint 95% confidence region for the weight and displacement
     # parameters in the Fuel dataset
     data(fuel.frame)
     fit <- lm(Fuel ~ . , fuel.frame)
     plot(ellipse(fit,which=c('Weight','Disp.')),type='l')

