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

# gbker(1)

Produce kernel density estimation

## NAME

gbker - Produce kernel density estimation

## SYNOPSIS

**gbker** \[*options*\]

## DESCRIPTION

Compute the kernel density estimation on an equispaced grid. Data are read from standard input. The kernel bandwidth, if not provided with the option **-H**, is set automatically using simple heuristics. Normally the whole support is displayed. The option **-w** can be used to restrict the computation to specific range of values. The method used to compute the density is set by the option **-M**. The boundaries of the grid are slightly different in the different cases.

## OPTIONS

- **-n**

  number of equispaced points/bins where the density is computed (default 64)

- **-w**

  set the grid boundaries with min,max (default whole support)

- **-H**

  set the kernel bandwidth

- **-S**

  scale the automatic kernel bandwidth

- **-K**

  choose the kernel to use  (default 0)

- 0

  Epanenchnikov

- 1

  Rectangular

- 2

  Gaussian

- 3

  Laplacian

- **-M**

  choose the method for density computation (default 0)

- 0

  use FFT (# grid points rounded to nearest power of 2)

- 1

  use discrete convolution (compact kernels only; bins\>2)

- 2

  explicit summation (boundaries excluded)

- **-F**

  specify the input fields separators (default " \\t")

## EXAMPLES

- gbker -n 128 -K 2 \< file

  use a Gaussian kernel to compute the density on 128 equispaced points with the FFT approach. All the data in 'file' are used, multiple columns are pooled.

- gbker -K 3 -M 2 \< file

  use a Laplacian kernel to compute the density on 64 points. The method used is the explicit summation.

## 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.