GBFUN(1) | User Commands | GBFUN(1) |

gbfun - Apply functions to table of data

**gbfun** [*options*] *<function definition>
*...

Compute specified functions on data read from standard input. The
default is to perform the computation column-wise, on each row of data
separately. 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 the function row-wise, on each column separately.
**-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 -T 'x0+log(x2)' < file
- print the log of the second row of 'file' adding the progressive number of the column
- 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 © 2001-2018 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.

March 2018 | gbfun 5.7.1 |