gbker(1)
Produce kernel density estimation
Description
GBKER
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.