pratergrouped            package:betareg            R Documentation

_G_r_o_u_p_e_d _P_r_a_t_e_r'_s _g_a_s_o_l_i_n_e _d_a_t_a

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

     Operational data of the proportion of crude oil converted to
     gasoline after distilation and fractionation.

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

     data(pratergrouped)

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

     A data frame with 32 observations on 11 variables. More details on
     the independent variables can be found in the details section
     below.

     [,1] 'oil'    The proportion of crude oil converted to gasoline
     after distilation and fractionation. [,2] 'batch1'  The first
     batch of crude oil. [,3] 'batch2'  The second batch of crude oil.
     [,4] 'batch3'  The third batch of crude oil. [,5] 'batch4'  The
     fourth batch of crude oil. [,6] 'batch5'  The fifth batch of crude
     oil. [,7] 'batch6'  The sixth batch of crude oil. [,8] 'batch7' 
     The seventh batch of crude oil. [,9] 'batch8'  The eighth batch of
     crude oil. [,10] 'batch9' The ninth batch of crude oil. [,11]
     'temp'   The temperature (degrees F) at which all the gasoline is
     vaporized.

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

     The dataset contains 32 observations on the response and on the
     independent variables. It has been noted (Daniel and Wood, 1971,
     Ch. 8) that there are only ten sets of values of the first three
     explanatory variables which correspond to ten different crudes and
     were subjected to experimentally controlled distilation
     conditions. This dataset was analyzed by Atkinson (1985), who used
     the linear regression model and noted that there is ``indication
     that the error distribution is not quite symmetrical, giving rise
     to some unduly large and small residuals'' (p. 60). He proceeded
     to transform the response so that the transformed dependent
     variable assumed values on the real line, and then used it in a
     linear regression analysis.

     The data were ordered according to the ascending order of the
     covariate that measures the temperature at which 10

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

     Prater, N.H. (1956). Estimate gasoline yields from crudes. New
     York: Springer-Verlag.

_R_e_f_e_r_e_n_c_e_s:

     Atkinson, A.C. (1985). _Plots, Transformations and Regression: An
     Introduction to Graphical Methods of Diagnostic Regression
     Analysis._ New York: Oxford University Press.

     Daniel, C. and Wood, F.S. (1971). _Fitting Equations to Data_. New
     York: Wiley

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

     data(pratergrouped)
     fit1 <- betareg(oil ~ batch1 + batch2 + batch3 + batch4 + batch5 + 
     batch6 + batch7 + batch8 + batch9 + temp, data=pratergrouped)
     fit2 <- betareg(oil ~ batch1 + batch2 + batch3 + batch4 + batch5 + batch6 + 
     batch7 + batch8 + batch9 + temp, link = "probit", data=pratergrouped)
     plot(fit1)

