phot.radprof.radcum_profile

phot.radprof.radcum_profile(
    im,
    center,
    radii=1,
    mask=None,
    var=None,
    err=None,
    return_var=False,
    add_npix=True,
    norm_by_last=False,
)

Calculate a cumulative radial profile with circular apertures.

Parameters

im : 2-D array

Image data.

center : tuple of float

Aperture center in (x, y) order.

radii : 1-D array = 1

Radii of the circular apertures.

mask : 2-D array = None

Boolean mask; True pixels are ignored. Default is None.

var : 2D array = None

Variance map. Its aperture sum is also computed. Mutually exclusive with err. Default is None.

err : 2D array = None

Error map, converted internally to variance (variance = error**2). Mutually exclusive with var. Default is None.

return_var : bool = False

If True, return the aperture sum as var without taking a square root. If False (default), return its square root as err. Requires either var or err.

add_npix : bool = True

Include npix (weighted unmasked aperture support) when True (default). Set False to skip the to_mask computation when counts are not needed.

norm_by_last : bool = False

Normalize all flux columns by the value at the largest radius when True. Default is False.

Returns

profs : pandas.DataFrame

DataFrame with these columns:

• r : aperture radius
• apsum: aperture sum within radius r
• npix : weighted unmasked aperture support (if add_npix=True)
• var : variance of apsum, sum(w**2 * var) with exact overlap weights w (if return_var=True and var/err is given)
• err : square root of var (if return_var=False and var/err is given)