gbfun - Apply functions to table of data

**gbfun** [

*options*]

*<function definition> *...

Compute arbitrary colum-wise functions on data read from standard input.
Variable 'xi' stands for the i-th column while 'x0' stands for the row number,
e.g. a function f(x1,x2) operates on the first and secod column. With the
option

**-t** the function is computed, in turn, on every column. In this
case f(x1,x2) stands for a function of the column itself and of the following
column (the index being a lead operator). In these cases 'x' is equivalent to
'x1'. With

**-r** or

**-R** the function is recursevely computed
"columwise" on each row. In this case the variable 'x' identifies
the result of the previous evaluation. A lag operator can be specified with
the letter l, like in 'x1l2', which means the first column two steps before.
More functions can be specified and will be considered in turn.

**-t**
- compute on each column

**-r**
- set initial value and compute recursively

**-R**
- set initial value, compute recursively and print
intermediary results

**-v**
- verbose mode

**-F**
- specify the input fields separators (default "
\t")

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

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

**-h**
- this help

- gbfun 'x0+log(x2)' file
- print the log of the second column of 'file' adding the
progressive number of the row

- gbfun -r 0 'x+sqrt(x1)' file
- print the sum of the square root of the elements of the
first column of 'file'

Written by Giulio Bottazzi

Report bugs to <gbutils@googlegroups.com>

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

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.