Website of Tobias Westmeier

BusyFit

Overview

• Introduction
• Screenshots
• Requirements
• Download
• Installation
• Documentation
• Version history
• Copyright and licence

Introduction

BusyFit is a stand-alone software for fitting the so-called Busy Function (Westmeier et al. 2014, MNRAS, 438, 1176) to the integrated spectrum of a galaxy for the purpose of parametrisation. It is entirely written in C++ and licensed under the GNU General Public License (version 3 or later).

Another Busy Function fitting software was developed by Russell Jurek and is available on GitHub.

Screenshots

The two screenshots above show the output of a successful BusyFit run in the terminal window (left) and a plot of the spectrum with overlaid fit and residuals produced by BusyFit using gnuplot (right).

Requirements

The following software packages are required to successfully compile and run BusyFit:

• Linux / Unix operating system (e.g. Ubuntu, Mac OS X) with graphical user interface (optional; required for plotting the fitted spectrum) and shell (e.g. bash, tcsh)
• GNU Compiler Collection (GCC), including C++ compiler (g++)
• GNU Scientific Library (GSL), including development (dev) packages
• GNU less (optional; required for help system)
• gnuplot (optional; required for plotting the fitted spectrum)

If you are running a GNU/Linux system on your computer, you will likely have all of these software packages either already installed or made available through your system’s package manager, so there should be no need to manually download and compile any of them.

GNU less and gnuplot are optional. The former is used to display the detailed help message and user manual when typing ‘busyfit -help’, while the latter is needed to automatically plot the fitted spectrum on the screen. Plotting can be disabled by invoking BusyFit with the ‘-noplot’ option.

Download

• Current version 0.2: busyfit-0.2.tar.gz (35 kB)
• Previous version 0.1: busyfit-0.1.tar.gz (31 kB)

To download the software, right-click on the desired version above and save the compressed archive to a folder of your choice.

Installation

To install BusyFit on your computer, open a terminal window and change into the folder where the downloaded archive was saved. To unpack the archive, type

where [ver] is the version number of the package you downloaded, e.g. 0.2. This will unpack all files into a new sub-directory called ‘BusyFit’.

Assuming that the GNU Scientific Library is installed at a location where it can be found by the compiler and linker, BusyFit can then simply be compiled by running the compile.sh script coming with the package. Change into the new ‘BusyFit’ sub-directory and type

This should compile the source code and generate an executable file named busyfit. To make the software accessible across the entire system, you may wish to create a symbolic link in /usr/bin. If you use Linux, simply type

where [installation directory] is the full path of the directory where the busyfit executable file is located. Alternatively, you could create an alias in the .alias, .cshrc, or .bashrc file (wherever you usually store your aliases) in your home directory.

The default installation directory for the GSL on Linux systems should be /usr/lib (for libgsl.a and libgslcblas.a) and /usr/include/gsl (for all header files). If that is not the case on your computer, then the correct paths must be provided to GCC by modifying the compile.sh script. This can be achieved by adding the ‘-L /path1’ and ‘-I /path2’ options to the three ‘g++’ calls, where /path1 is the full path to the directory where libgsl.a is located, and /path2 is the full path (without the final ‘gsl’ folder) to the directory where the GSL header files are stored (e.g., gsl_rng.h). This should enable GCC to find all required GSL files.

Documentation

The BusyFit software package comes with its own internal help system and user manual. A simple overview of all available options will be displayed by calling ‘busyfit’ without any options or input file name. A more detailed user manual can be displayed by typing ‘busyfit -help’.

The following example illustrates how to use BusyFit in its most basic form:

The spectrum to be fitted is read from a simple text file (spectrum.txt in the example above) where the velocity and flux values of the spectrum must be located in two columns the positions of which are specified with the -c option (the third column for velocities, the fourth column for fluxes in the example above). Without the -c option, BusyFit will read the first two columns of the input file by default. Please see the

• BusyFit User Manual v0.2 (current)
• BusyFit User Manual v0.1 (outdated)

for a detailed description of all available options, including specifying the noise level, providing initial estimates of the free parameters, fixing individual parameters, etc.

Version history

• BusyFit 0.2
  • Released 10/09/2015
  • BusyFit now fits the exponent of the polynomial component as well.
  • BusyFit can now be made to automatically measure the rms noise of the spectrum under certain conditions.
  • It is now possible to specify the column containing the spectral axis of the spectrum. BusyFit will use this information to provide all physical parameters in their native spectral units (e.g. velocity in km/s) rather than just channels.
• BusyFit 0.1
  • Released 25/09/2013
  • Initial, stable release of the package with basic functionality and built-in help system

Copyright and licence

If you publish results that have been derived with the help of this software, I would appreciate a reference to the original paper describing the Busy Function:

• The busy function: a new analytic function for describing the integrated 21-cm spectral profile of galaxies. Westmeier, T., Jurek, R., Obreschkow, D., Koribalski, B. S., Staveley-Smith L., 2014, MNRAS, 438, 1176 (ADS | arXiv)

BusyFit is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

BusyFit 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.

You should have received a copy of the GNU General Public License along with BusyFit. If not, see http://www.gnu.org/licenses/.

© 2015 Tobias Westmeier