acid                 package:assist                 R Documentation

_L_a_k_e _A_c_i_d_i_t_y _S_t_u_d_y

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

     The 'acid' data frame has 112 rows and 4 columns of data derived
     based on the Eastern Lakes Survey of 1984 implemented by the
     Environmental Protection Agency of the USA.

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

     data(acid)

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

     The data frame contains the following columns:

     ph a numeric vector of surface pH values.

     t1 a numeric vector of calcium concentrations in log10 milligrams
     per liter.

     x1, x2 numeric vectors of the lakes' geographic locations.

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

     112 lakes are extracted in the southern Blue Ridge mountains area.
     The surface pH values were recorded together with the calcium
     concentration and geographic locations.

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

     Douglas, A. and Delampady, M. (1990), Eastern Lake Survey Phase I:
     Documentation for the Data Base and the Derived Data sets. Tech
     Report 160 (SIMS), Dept. Statistics, University of British
     Columbia.

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

     Gu, C. and Wahba, G. (1993) Smoothing Spline ANOVA with
     component-wise Bayesian confidence intervals. Journal of
     Computational and Graphic Statistics 55, 353-368.

