read.dta               package:foreign               R Documentation

_R_e_a_d _S_t_a_t_a _B_i_n_a_r_y _F_i_l_e_s

_D_e_s_c_r_i_p_t_i_o_n:

     Reads a file in Stata version 5-10 binary format into a data
     frame.

_U_s_a_g_e:

     read.dta(file, convert.dates = TRUE, convert.factors = TRUE,
              missing.type = FALSE,
              convert.underscore = FALSE, warn.missing.labels = TRUE)

_A_r_g_u_m_e_n_t_s:

    file: a filename or URL as a character string.

convert.dates: Convert Stata dates to 'Date' class?

convert.factors: Use Stata value labels to create factors? (version 6.0
          or later).

missing.type: For version 8 or later, store information about different
          types of missing data?

convert.underscore: Convert '"_"' in Stata variable names to '"."' in R
          names?

warn.missing.labels: Warn if a variable is specified with value labels
          and those value labels are not present in the file.

_D_e_t_a_i_l_s:

     If the filename appears to be a URL (of schemes 'http:', 'ftp:' or
     'https:') the URL is first downloaded to a temporary fiie and then
     read.  ('https:' is only supported on some platforms.)

     The variables in the Stata data set become the columns of the data
     frame.  Missing values are correctly handled.  The data label,
     variable labels, and timestamp are stored as attributes of the
     data frame.  Nothing is done with variable characteristics.

     By default Stata dates (%d and %td formats) are converted to R's
     'Date' class and variables with Stata value labels are converted
     to factors.  Ordinarily, 'read.dta' will not convert a variable to
     a factor unless a label is present for every level.  Use
     'convert.factors = NA' to override this.  In any case the value
     label and format information is stored as attributes on the
     returned data frame.

     Stata 8.0 introduced a system of 27 different missing data values.
      If 'missing.type' is 'TRUE' a separate list is created with the
     same variable names as the loaded data.  For string variables the
     list value is 'NULL'.  For other variables the value is 'NA' where
     the observation is not missing and 0-26 when the observation is
     missing.  This is attached as the '"missing"' attribute of the
     returned value.

_V_a_l_u_e:

     a data frame with attributes.  These will include '"datalabel"',
     '"time.stamp"', '"formats"', '"types"', '"val.labels"',
     '"var.labels"' and '"version"' and may include '"label.table"'. 
     Possible versions are '5, 6, 7', '-7' (Stata 7SE, 'format-111'),
     '8' (Stata 8 and 9, 'format-113') and '10' (Stata 10,
     'format-114').

     The value labels in attribute '"val.labels"' name a table for each
     variable, or are an empty string.  The tables are elements of the
     named list attribute '"label.table"': each is an integer vector
     with names,

_A_u_t_h_o_r(_s):

     Thomas Lumley

_R_e_f_e_r_e_n_c_e_s:

     Stata Users Manual (versions 5 & 6), Programming manual (version
     7), or online help (version 8, 9, 10) describe the format of the
     files. Or at <URL: http://www.stata.com/help.cgi?dta> and <URL:
     http://www.stata.com/help.cgi?dta_113>

_S_e_e _A_l_s_o:

     'write.dta', 'attributes' 'Date' 'factor'

_E_x_a_m_p_l_e_s:

     data(swiss)
     write.dta(swiss,swissfile <- tempfile())
     read.dta(swissfile)