jist                package:ProfessR                R Documentation

_A_d_d _l_e_t_t_e_r _g_r_a_d_e_s _t_o _h_i_s_t_o_g_r_a_m

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

     Given a vector of grades, add the letters to an existing
     histogram.

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

     jist(h, Z=1, L=1, col=2)

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

       h: histogram list

       Z: grades from original data

       L: letters associated with grades

     col: color for plotting letters

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

     This will add information on an existing histogram plot.  If h is
     the output of do.grades() then Z and L are ignored.

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

     Graphical Side effects

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

     Jonathan M. Lees<jonathan.lees@unc.edu>

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

     do.grades

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

     g = rnorm(130, m=82, sd=10)
     g[g>100] = 100
     g[g<1] = 1

     B = boxplot(g)

     divs = c(min(g), B$stats[1:4] + diff(B$stats)/2, max(g) )

     ####G1  = do.grades(g, cut=20, tit="GEOL 105 Exam 1")

     ##########  replot with existing divisions:
     D1 = do.grades(g, divs=divs, tit="GEOL 105 Exam 1")

     jist(D1$hist, D1$grades, D1$lett)

     ##########  or simply:

     D1 = do.grades(g, divs=divs, tit="GEOL 105 Exam 1")

     jist(D1)

