guess_radius

sherpa.utils.guess_radius(x0lo: ndarray, x1lo: ndarray, x0hi: Literal[None], x1hi: Literal[None]) → ValueAndRange

sherpa.utils.guess_radius(x0lo: ndarray, x1lo: ndarray, x0hi: ndarray, x1hi: ndarray) → ValueAndRange

Guess the radius parameter of a 2D model.

Parameters:

x0lo, x1loarray_like

The independent axes of the grid, in 1D form.

x0hi, x1hiarray_like or None, optional

The upper bounds of each pixel.

Returns:

ansdict

The keys are ‘val’, ‘min’, and ‘max’, which give the radius and its range, in units of the input grid (x0lo and x1lo).

Notes

Currently only x0lo is used, and it is assumed to be arranged so that this axis varies fastest (that is x0lo[1] > x0lo[0]) as well as representing square pixels of the same size.

The scaling factor for the minimum and maximum values is taken from the module’s _guess_ampl_scale variable.