sep.flux_radius(data, x, y, rmax, frac, normflux=None, mask=None, maskthresh=0.0, subpix=5)

Return radius of a circle enclosing requested fraction of total flux.

data : ndarray

2-d array to be summed.

x, y : array_like

Center coordinates and radius (radii) of aperture(s). x corresponds to the second (“fast”) axis of the input array and y corresponds to the first (“slow”) axis. x, y = (0.0, 0.0) corresponds to the center of the first element of the array. Shapes must match.

rmax : array_like

Maximum radius to analyze. Used as normalizing flux if normflux is None. Shape must match x and y.

frac : array_like

Requested fraction of light (in range 0 to 1). Can be scalar or array.

normflux : array_like, optional

Normalizing flux for each position. If not given, the sum within rmax is used as the normalizing flux. If given, shape must match x, y and rmax.

mask : ndarray, optional

Mask array. If supplied, a given pixel is masked if its value is greater than maskthresh.

maskthresh : float, optional

Threshold for a pixel to be masked. Default is 0.0.

segmap : ndarray, optional

Segmentation image with dimensions of data and dtype np.int32. This is an optional input and corresponds to the segmentation map output by extract.

seg_id : array_like, optional

Array of segmentation ids used to mask additional pixels in the image. Dimensions correspond to the dimensions of x and y. The behavior differs depending on whether seg_id is negative or positive. If seg_id is positive, all pixels belonging to other objects are masked. (Pixel j, i is masked if seg[j, i] != seg_id and seg[j, i] != 0). If seg_id is negative, all pixels other than those belonging to the object of interest are masked. (Pixel j, i is masked if seg[j, i] != -seg_id). NB: must be included if ``segmap` is provided.

subpix : int, optional

Subpixel sampling factor. Default is 5.

radius : ndarray

The sum of the data array within the aperture(s). Shape is same as x, except if frac is an array; then the dimension of frac will be appended. For example, if x and frac are both 1-d arrays, the result will be a 2-d array with the trailing dimension corresponding to frac.

flags : ndarray

Integer giving flags. Same shape as x. (0 if no flags set.)