traps.info               package:secr               R Documentation

_D_e_t_e_c_t_o_r _A_t_t_r_i_b_u_t_e_s

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

     Extract or replace attributes of an object of class 'traps'.

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

     polyID(object)
     polyID(object) <- value
     transectID(object)
     transectID(object) <- value
     searcharea(object)
     searcharea(object) <- value
     transectlength(object)

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

  object: a 'traps' object 

   value: replacement value (see Details) 

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

     The 'polyID' and 'transectID' functions assign and extract the
     attribute of a 'traps' object that relates vertices (rows) to
     particular polygons or transects. The replacement value should be
     a factor of length equal to nrow(object).

     The 'searcharea' attribute of a 'quadratbinary' or 'quadratcount'
     traps object is the area in hectares searched at each detector
     point (quadrat). Usually, this is the area of a rectangular pixel
     determined by the detector spacing (spacex, spacey). Replacement
     creates square pixels with dimensions spacex = spacey = value^0.5
     * 100. 

     The 'searcharea' of a 'polygon' traps object is a vector of the
     areas of the component polygons. This is a read-only value (i.e.
     'searcharea<-' does not apply).

     The 'transectlength' of a 'transect' traps object is a vector of
     the lengths of the component transects in metres. This is a
     read-only value.

_V_a_l_u_e:

     'polyID' - a factor with one level per polygon. 'searcharea' -
     numeric value of quadrat area or polygon areas, in hectares.
     'transectlength' - numeric value of transect lengths, in metres.

_A_u_t_h_o_r(_s):

     Murray Efford murray.efford@otago.ac.nz

_S_e_e _A_l_s_o:

     'traps'

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

     ## default is a single polygon
     temp <- make.grid(detector = 'polygon', hollow = TRUE)
     polyID(temp)
     plot(temp)

     ## split in two
     temp <- make.grid(detector = 'polygon', hollow = TRUE)
     polyID(temp) <- factor(rep(c(1,2),rep(10,2)))
     plot(temp)
      

