Convolution

A convolution model requires both the evaluation grid and the data to convolve. Examples include using a point-spread function (PSF) model to modify a two-dimensional model to account for blurring due to the instrument (or other sources, such as the atmosphere for ground-based Astronomical data sets), or the redistribution of the counts as a function of energy as modelled by the RMF when analyzing astronomical X-ray spectra.

Note

The convolution kernel may require grid points that are not within the requested range. The two-dimensional PSF models support this when using the Session layer, via the sherpa.astro.ui.set_psf() function. It is not yet obvious to me how this is handled at this level. The PHA case is handled by the sherpa.astro.instrument.RSPModelPHA class (and related classes), but it is still not clear how to document and use.