guess_radius

sherpa.utils.guess_radius(x0lo, x1lo, x0hi=None, x1hi=None)[source] [edit on github]

Guess the radius parameter of a 2D model.

Parameters
  • x0lo (array_like) – The independent axes of the grid, in 1D form.

  • x1lo (array_like) – The independent axes of the grid, in 1D form.

  • x0hi (array_like or None, optional) – The upper bounds of each pixel.

  • x1hi (array_like or None, optional) – The upper bounds of each pixel.

Returns

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

Return type

dict

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.