Imfit is an open-source C++ program for fitting models to astronomical images (primarily of galaxies). It is fast, flexible, and designed to be easily extended with new functions for components of the model image.

Examples of Use:

Fitting an image (with a model specified in the configuration file model_description.txt):

$ imfit someimage.fits --config model_description.txt

Fitting a subsection of the image and convolving the model with a Point-Spread-Function image, using Differential Evolution as the solver:

$ imfit someimage.fits[500:750,600:800] --config model_description.txt --psf psf.fits --de

Markov Chain Monte Carlo (MCMC) analysis of the same image and model:

$ imfit-mcmc someimage.fits[500:750,600:800] --config model_description.txt --psf psf.fits

Useful things:

  • imfit -h – lists command-line flags and options

  • imfit --list-functions – lists all available image functions for models

  • imfit --list-parameters – lists the individual parameters for all image functions

  • imfit --sample-config – writes a sample configuration file to the current directory

The main documentation for Imfit is in the PDF file imfit_howto.pdf.

Where to Get It:

Pre-compiled binaries for Linux and macOS, along with the source code for compilation, are available here.

The full source-code distribution is available at Imfit’s Github page.

Indices and tables