pcbs                  package:GRASS                  R Documentation

_P_C_B_s _i_n _a_n _a_r_e_a _o_f _S_o_u_t_h _W_a_l_e_s

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

     The 'pcbs' data frame has 70 rows and 3 columns. It records
     contamination of the environment with polychlorinated biphenyls
     around the site of a large plant for the incineration of chemical
     wastes near Pontypool, South Wales.

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

     data(pcbs)

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

     This data frame contains the following columns:

     _e_a_s_t a numeric vector - UTM zone 30 eastings coordinates

     _n_o_r_t_h a numeric vector - UTM zone 30 northings coordinates

     _p_c_b_s a numeric vector - standardised scores for seven types of PCB

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

     The original data were positioned in relation to National Grid
     coordinates, and have been reprojected to UTM zone 30, using the
     WGS84 ellipsoid.

_N_o_t_e:

     This dataset will only work if R is started from inside GRASS,
     choosing the location for the Pontypool PCBs data. GRASS
     installations differ in permissions needed to establish a new
     location, and system administrator privileges may be needed to
     create the Pontypool location. Information about the necessary
     metadataare as follows. The actual data may be accessed from R:
     'data(pcbs)'.

     _p_r_o_j_e_c_t_i_o_n  UTM

     _e_l_l_i_p_s_o_i_d  WGS84

     _z_o_n_e  30

     _n_o_r_t_h  77200

     _s_o_u_t_h  74500

     _w_e_s_t  68000

     _e_a_s_t  70200

     _n_s_r_e_s  25

     _e_w_r_e_s  25

     _r_o_w_s  108

     _c_o_l_s  88

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

     Bailey, T. C., Gatrell, A. C. 1995 Interactive Spatial Data
     Analysis (Longman, Harlow); pages 149-150, courtesy of Andrew
     Lovett, School of Environmental Sciences, University of East
     Anglia.

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

     data(pcbs)
     pcbs.o <- as.ordered(cut(pcbs$pcbs, labels=c("insignificant", "low",
     "medium", "high", "crisis"), breaks=c(1,20,100,500,1000,5000),
     include.lowest=TRUE))
     table(pcbs.o)
     plot(pcbs$east, pcbs$north, pch=unclass(pcbs.o), xlab="", ylab="", asp=1)
     legend(x=c(67980, 68480), y=c(74710, 75180), pch=c(1:5), legend=levels(pcbs.o))

