![]() Poisson-based maximum likelihood statistics (such as the Cash statistic Cash 1979) User-supplied dispersion or variance maps. The per-pixel dispersions used in the χ 2 calculation canīe estimated from the data or from the model, or they can come from (much slower, but requires no initial guess and is even less likely to beĪ companion program can do Markov chain Monte Carlo (MCMC) analysis of the model +ĭata combination as well, using the same parameter files, statistical approaches, and Nelder-Mead simplex (slower, but less likely toīe trapped in local minima in the χ 2 landscape).The χ 2 minimization can be done using one of three algorithms: Or Moffat functions - or any combination of the functions built into Imfit.) (A companion program can be used to generate PSF images based on, e.g., 2D Gaussian One or more subsections of the image can also be specified for convolution with oversampled PSF Match the input image the PSF image can be any square, centered image the user supplies. Model image can be convolved with a Point Spread Function (PSF) image to better Parameters for individualįunctions can be held fixed or restricted to user-specified ranges. ![]() Position on the image plane this allows fitting galaxies with off-center components, Individual 2D functions can be grouped into arbitrary sets sharing a common ( x,y) ![]() Imfit can be compiled to use multi-threadingĪdvantage of multiple cores in modern CPUs for extra speed. ![]() This model image is then matched to the input image by adjusting the 2Dįunction parameters via nonlinear minimization of the total Image functions (e.g., elliptical exponential, elliptical Sérsic,Ĭircular Gaussian) which are added together to generate a model image. The user can specify a set of one or more 2D Imfit is a program for fitting astronomical images -Įspecially images of galaxies, though it can be used forįitting other sources. Imfit: 2D Multi-component Fitting of Galaxy Images Imfit:įast, Flexible Multi-component Fitting of Galaxy ImagesĪbout Downloads Example of Use Tutorial/Quickstart ![]()
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