stats                  package:Rlab                  R Documentation

_C_a_l_c_u_l_a_t_e _s_u_m_m_a_r_y _s_t_a_t_i_s_t_i_c_s

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

     Various summary statistics are calculated for different types of
     data.

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

     stats(x, by)

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

       x: The data structure to compute the statistics. This can either
          be a vector, matrix (data sets are the columns), or a list
          (data sets are the components).  

      by: If x is a vector, an optional vector (either character or
          numerical) specifying the categories to divide x into
          separate data sets. 

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

     Stats breaks x up into separate data sets and then calls describe
     to calculate the statistics. Statistics are found by columns for
     matrices, by components for a list and by the relevent groups when
     a numeric vector and a by vector are given. The default set of
     statistics are the number of (nonmissing) observations, mean,
     standard deviation, minimum, lower quartile, median, upper
     quartile, maximum, and number of missing observations. If any data
     set is nonnumeric, missing values are returned for the statistics.
     The by argument is a useful way to calculate statistics on parts
     of a data set according to different cases.

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

     A matrix where rows index the summary statistics and the columns
     index the separate data sets.

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

     stats.bplot, mean, sd

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

     #Statistics for 8 normal random samples: 
     zork<- matrix( rnorm(200), ncol=8) 
     stats(zork) 

     zork<- rnorm( 200)
     id<- sample( 1:8, 200, replace=TRUE)
     stats( zork, by=id)

