---
name: "gbnlmult"
section: "1"
platform: "linux"
package: "gbutils"
version: "6.3-1+b1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/gbnlmult"
---

# gbnlmult(1)

Solve systems of non linear simultaneous equations

## NAME

gbnlmult - Solve systems of non linear simultaneous equations

## SYNOPSIS

**gbnlmult** \[*options*\] *\<function definition\>*

## DESCRIPTION

Least square estimation of a system of j non linear equations. Read data in columns (X\_1 .. X\_N). The j-th equation is specified by a function f\_j(x1,x2...) using variables names x1,x2,..,xN for the first, second...N-th column of data. The f\_j(x1,x2,...)'s are assumed i.i.d. according to a multivariate gaussian distribution.

## OPTIONS

- **-O**

  type of output (default 0)

- 0

  parameters

- 1

  parameters and errors

- 2

  \<variables\> and residuals

- 3

  parameters and variance matrix

- **-V**

  variance matrix estimation (default 0)

-

  0 \<gradF gradF^t\> 1  \< J^{-1} \> 2 \< H^{-1} \> 3  \< H^{-1} J H^{-1} \>

- **-e**

  minimization tolerance (default 1e-5)

- **-v**

  verbosity level (default 0)

- 0

  just results

- 1

  comment headers

- 2

  summary statistics

- 3

  covariance matrix

- 4

  minimization steps

- 5

  model definition

- **-F**

  input fields separators (default " \\t")

- **-h**

  this help

## 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 © 2001-2018 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.