read.columns              package:limma              R Documentation

_R_e_a_d _s_p_e_c_i_f_i_e_d _c_o_l_u_m_n_s _f_r_o_m _a _f_i_l_e

_D_e_s_c_r_i_p_t_i_o_n:

     Reads specified columns from a file in table format and creates a
     data frame from it, with cases corresponding to lines and
     variables to fields in the file.

_U_s_a_g_e:

     read.columns(file,required.col=NULL,text.to.search="",sep="\t",quote="\"",skip=0,fill=TRUE,blank.lines.skip=TRUE,comment.char="",allowEscapes=FALSE,...)

_A_r_g_u_m_e_n_t_s:

    file: the name of the file which the data are to be read from.

required.col: character vector of names of the required columns

text.to.search: character string. If any column names can be found in
          this string, those columns will also be read.

     sep: the field separator character

   quote: character string of characters to be treated as quote marks

    skip: the number of lines of the data file to skip before beginning
          to read data.

    fill: logical: if 'TRUE' then in case the rows have unequal length,
          blank fields are implicitly added.

blank.lines.skip: logical: if 'TRUE' blank lines in the input are
          ignored.

comment.char: character: a character vector of length one containing a
          single character or an empty string.

allowEscapes: logical. Should C-style escapes such as '\n' be processed
          or read verbatim (the default)?

     ...: other arguments are passed to 'read.table', excluding the
          following which are reserved and cannot be set by the user:
          'header', 'col.names', 'check.names' and 'colClasses'.

_D_e_t_a_i_l_s:

     This function is an interface to 'read.table' in the base package.
     It uses 'required.col' and 'text.to.search' to set up the
     'colClasses' argument of 'read.table'.

     Note the following arguments of 'read.table' are used by
     'read.columns' and therefore cannot be set by the user: 'header',
     'col.names', 'check.names' and 'colClasses'.

     This function is used by 'read.maimages'.

_V_a_l_u_e:

     A data frame (data.frame) containing a representation of the data
     in the file.

_A_u_t_h_o_r(_s):

     Gordon Smyth

_S_e_e _A_l_s_o:

     'read.maimages', 'read.table'.

     An overview of LIMMA functions for reading data is given in
     03.ReadingData.