Kirby2                package:NISTnls                R Documentation

_M_i_c_r_o_s_c_o_p_e _l_i_n_e _w_i_d_t_h _s_t_a_n_d_a_r_d_s

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

     The `Kirby2' data frame has 151 rows and 2 columns of data from an
     NIST study on scanning electron microscope line width standards.

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

       y: A numeric vector of response values. 

       x: A numeric vector of input values. 

_F_o_r_m_a_t:

     This data frame contains the following columns:

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

     These data are the result of a NIST study involving scanning
     electron microscope line with standards.

_S_o_u_r_c_e:

     Kirby, R., NIST (197?).   Scanning electron microscope line width
     standards.

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

     data(Kirby2)
     plot(y ~ x, data = Kirby2)
     fm1 <- nls(y ~ (b1 + b2*x + b3*x**2) / (1 + b4*x + b5*x**2),
                data = Kirby2, trace = TRUE,
                start = c(b1 = 2, b2 = -0.1, b3 = 0.003, b4 = -0.001, b5 = 0.00001))
     fm2 <- nls(y ~ (b1 + b2*x + b3*x**2) / (1 + b4*x + b5*x**2),
                data = Kirby2, trace = TRUE,
                start = c(b1 = 1.5, b2 = -0.15, b3 = 0.0025, b4 = -0.0015,
                          b5 = 0.00002))
     fm3 <- nls(y ~ cbind(1, x, x**2)/(1 + x*(b4 + b5*x)),
                data = Kirby2, trace = TRUE, algorithm = "plinear",
                start = c(b4 = -0.001, b5 = 0.00001))
     fm4 <- nls(y ~ cbind(1, x, x**2)/(1 + x*(b4 + b5*x)),
                data = Kirby2, trace = TRUE, algorithm = "plinear",
                start = c(b4 = -0.0015, b5 = 0.00002))

