

InsectSprays {base}                          R Documentation

_E_f_f_e_c_t_i_v_e_n_e_s_s _o_f _I_n_s_e_c_t _S_p_r_a_y_s

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

     The counts of insects in agricultural experimental
     units treated with different insecticides.

_U_s_a_g_e_:

     data(InsectSprays)

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

     A data frame with 72 observations on 2 variables.

      [,1]      count      numeric      Insect count
      [,2]      spray      factor       The type of spray

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

     Geoffrey Beall, (1942).  ``The Transformation of Data
     from Entomological Field Experiments'', Biometrika,
     pages 243-262.

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

     McNeil, D. (1977).  Interactive Data Analysis.  New
     York: Wiley.

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

     data(InsectSprays)
     boxplot(count ~ spray, data = InsectSprays,
             xlab = "Type of spray", ylab = "Insect count",
             main = "InsectSprays data", varwidth = TRUE, col = "lightgray")
     fm1 <- aov(count ~ spray, data = InsectSprays)
     summary(fm1)
     opar <- par(mfrow = c(2,2), oma = c(0, 0, 1.1, 0))
     plot(fm1)
     fm2 <- aov(sqrt(count) ~ spray, data = InsectSprays)
     summary(fm2)
     plot(fm2)
     par(opar)

