stats                 package:fields                 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.bin, stats.bplot, describe

_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)

