NAME

       gbget - Basic data extraction and manipulation tool

SYNOPSIS

       gbget [options] 'filename[index](C,R)trans'

DESCRIPTION

       Print slices of tabular data from files and apply transformations. Data are read from text
       files with fields separated by space (use option -F to  specify  a  different  separator).
       Inside  data  file,  data-blocks  are separated by two empty lines. File can be compressed
       with zlib (.gz).

       filename
              is the input file. If not specified it default  to  stdin  or  the  last  specified
              filename if any.

       index  stands for a data-block index.

       index  stands for a data-block index.

       C,R    stands  for  columns  and rows spec given as "min:max:skip" to select from "min" to
              "max" every "skip" steps. If negative min and max are  counted  from  the  end.  By
              default all data are printed ("1:-1:1"). If min>max then count is reversed and skip
              must be negative (-1 by default). Different specs are separated  by  semicolon  ';'
              and considered sequentially.

       trans  is  a  list  of  transformations  applied  to  selected  data: 'd' take the diff of
              subsequent columns; 'D' remove all rows with at least one Not-A-Number (NAN) entry;
              'f'  flatten  the output piling all columns; 'l' take log of all entries, 'P' print
              all entries collected as a data-block;  't'  transpose  the  matrix  of  data;  'z'
              subtract  from the entries in each column their mean; 'Z' replace the entry in each
              column with their zscore; 'w' divide the entry in each columns by their mean.

              '<..;..>' functions separated by semicolons in  angle  brackets  can  be  used  for
              generic  data  transformation;  the  function  is  computed  for  each row of data.
              Variables names are 'x' followed by the number of the column and optionally by  'l'
              and  the number of lags. For instance 'x2+x3l1' means the sum of the entries in the
              2nd column plus the entries in the 3rd column in the previous row. 'x0' stands  for
              the row number and 'x' is equal to 'x1'

              '<@..;..>'  if  the  functions  specification  starts  with a '@' the functions are
              computed recursively along the columns. In this case the number after  the  'x'  is
              the relative column counted starting from the one considered at each step.

              '{...}'  a  function  in  curly  brackets can be use to select data: only rows that
              return a non-negative value are retained

OPTIONS

       -F     set the input fields separators (default ' \t')

       -o     set the output format (default '%12.6e')

       -e     set the output format for empty fields  (default '%13s')

       -s     set the output separation string  (default ' ')

       -t     define global transformations applied before each output (default '')

       -v     verbose mode

EXAMPLES

       gbget 'file(1:3)ld'
              select the first three columns in 'file',  take  the  log  and  the  difference  of
              successive columns;

       gbget 'file(2,-10:-1)
              <x^2> select the last ten elements of the second' of 'file' and print their squares

       gbget '[2]()' '[1]()' < ...
              select the second and first data block from the standard input.

       gbget 'file(1:3)<x1*x2-x3>'
              select  the  first  three  columns in 'file' and in each row multiply the first two
              entries and.  subtract the third.

       gbget 'file()<@x1+x2>'
              print the sum of two subsequent columns

       gbget 'file(1:3){x2-2}'
              select the first three columns in 'file' for the rows whose  second  field  is  not
              lower then 2

AUTHOR

       Written by Giulio Bottazzi

REPORTING BUGS

       Report bugs to <gbutils@googlegroups.com>

       Package home page <http://cafim.sssup.it/~giulio/software/gbutils/index.html>

COPYRIGHT

       Copyright  © 2001-2015 Giulio Bottazzi This program is free software; you can redistribute
       it and/or modify it under the terms of the GNU  General  Public  License  (version  2)  as
       published by the Free Software Foundation;

       This  program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
       without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR  PURPOSE.
       See the GNU General Public License for more details.