Misra1a               package:NISTnls               R Documentation

_M_o_n_o_m_o_l_e_c_u_l_a_r _A_b_s_o_r_p_t_i_o_n _D_a_t_a

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

     The 'Misra1a' data frame has 14 rows and 2 columns.

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

     This data frame contains the following columns:

     _y A numeric vector of volume values.

     _x A numeric vector of pressure values.


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

     These data are the result of a NIST study regarding dental
     research in monomolecular adsorption.  The response variable is
     volume, and the predictor variable is pressure.

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

     Misra, D., NIST (1978). Dental Research Monomolecular Adsorption
     Study.

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

     Try <- function(expr) if (!inherits(val <- try(expr), "try-error")) val
     plot(y ~ x, data = Misra1a)
     Try(fm1 <- nls(y ~ b1*(1-exp(-b2*x)), data = Misra1a, trace = TRUE,
                start = c(b1 = 500, b2 = 0.0001) ))
     Try(fm1a <- nls(y ~ b1*(1-exp(-b2*x)), data = Misra1a, trace = TRUE,
                alg = "port", start = c(b1 = 500, b2 = 0.0001) ))
     Try(fm2 <- nls(y ~ b1*(1-exp(-b2*x)), data = Misra1a, trace = TRUE,
                start = c(b1 = 250, b2 = 0.0005) ))
     Try(fm2a <- nls(y ~ b1*(1-exp(-b2*x)), data = Misra1a, trace = TRUE,
                alg = "port", start = c(b1 = 250, b2 = 0.0005) ))
     Try(fm3 <- nls(y ~ 1-exp(-b2*x), data = Misra1a, trace = TRUE,
                start = c(b2 = 0.0001), algorithm = "plinear" ))
     Try(fm4 <- nls(y ~ 1-exp(-b2*x), data = Misra1a, trace = TRUE,
                start = c(b2 = 0.0005), algorithm = "plinear" ))

     ## Using a self-starting model
     Try(fm5 <- nls(y ~ SSasympOrig(x, Asym, lrc), data = Misra1a))

