fruitohms                package:DAAG                R Documentation

_E_l_e_c_t_r_i_c_a_l _R_e_s_i_s_t_a_n_c_e _o_f _K_i_w_i _F_r_u_i_t

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

     Data are from a study that examined how the electrical resistance
     of a slab of kiwifruit changed with the apparent juice content.

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

     fruitohms

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

     This data frame contains the following columns:

     _j_u_i_c_e apparent juice content (percent) 

     _o_h_m_s electrical resistance (in ohms)

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

     Harker, F. R. and Maindonald J.H. 1994. Ripening of nectarine
     fruit. Plant Physiology 106: 165 - 171.

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

     plot(ohms ~ juice, xlab="Apparent juice content (%)",ylab="Resistance (ohms)", data=fruitohms)
     lines(lowess(fruitohms$juice, fruitohms$ohms), lwd=2)
     pause()

     require(splines)
     attach(fruitohms)
     plot(ohms ~ juice, cex=0.8, xlab="Apparent juice content (%)",
          ylab="Resistance (ohms)", type="n")
     fruit.lmb4 <- lm(ohms ~ bs(juice,4))
     ord <- order(juice)
     lines(juice[ord], fitted(fruit.lmb4)[ord], lwd=2)
     ci <- predict(fruit.lmb4, interval="confidence")
     lines(juice[ord], ci[ord,"lwr"])
     lines(juice[ord], ci[ord,"upr"])

