ProfileBase

class photutils.profiles.ProfileBase(data, xycen, radii, *, error=None, mask=None, method='exact', subpixels=5)

Bases: object

Abstract base class for profile classes.

Parameters:

data2D ndarray

The 2D data array. The data should be background-subtracted.

xycentuple of 2 floats

The (x, y) pixel coordinate of the source center.

radii1D float ndarray

An array of radii defining the radial bins. radii must be strictly increasing with a minimum value greater than or equal to zero, and contain at least 2 values. The radial spacing does not need to be constant. For RadialProfile, the input radii are the edges of the radial annulus bins, and the output radius represents the bin centers.

error2D ndarray, optional

The 1-sigma errors of the input data. error is assumed to include all sources of error, including the Poisson error of the sources (see calc_total_error) . error must have the same shape as the input data.

mask2D bool ndarray, optional

A boolean mask with the same shape as data where a True value indicates the corresponding element of data is masked. Masked data are excluded from all calculations.

method{‘exact’, ‘center’, ‘subpixel’}, optional

The method used to determine the overlap of the aperture on the pixel grid:

• 'exact' (default): The exact fractional overlap of the aperture and each pixel is calculated. The aperture weights will contain values between 0 and 1.

• 'center': A pixel is considered to be entirely in or out of the aperture depending on whether its center is in or out of the aperture. The aperture weights will contain values only of 0 (out) and 1 (in).

• 'subpixel': A pixel is divided into subpixels (see the subpixels keyword), each of which are considered to be entirely in or out of the aperture depending on whether its center is in or out of the aperture. If subpixels=1, this method is equivalent to 'center'. The aperture weights will contain values between 0 and 1.

subpixelsint, optional

For the 'subpixel' method, resample pixels by this factor in each dimension. That is, each pixel is divided into subpixels**2 subpixels. This keyword is ignored unless method='subpixel'.

Attributes Summary

profile	The radial profile as a 1D ndarray.
profile_error	The radial profile errors as a 1D ndarray.
radius	The profile radius in pixels as a 1D ndarray.

Methods Summary

normalize([method])	Normalize the profile.
plot([ax])	Plot the profile.
plot_error([ax])	Plot the profile errors.
unnormalize()	Unnormalize the profile back to the original state before any calls to normalize.

Attributes Documentation

profile

The radial profile as a 1D ndarray.

profile_error

The radial profile errors as a 1D ndarray.

radius

The profile radius in pixels as a 1D ndarray.

Methods Documentation

normalize(method='max')

Normalize the profile.

Parameters:

method{‘max’, ‘sum’}, optional

The method used to normalize the profile:

• 'max' (default): The profile is normalized such that its maximum value is 1.

• 'sum': The profile is normalized such that its sum (integral) is 1.

plot(ax=None, **kwargs)

Plot the profile.

Parameters:

axmatplotlib.axes.Axes or None, optional

The matplotlib axes on which to plot. If None, then the current Axes instance is used.

**kwargsdict, optional

Any keyword arguments accepted by matplotlib.pyplot.plot.

Returns:

lineslist of Line2D

A list of lines representing the plotted data.

plot_error(ax=None, **kwargs)

Plot the profile errors.

Parameters:

axmatplotlib.axes.Axes or None, optional

The matplotlib axes on which to plot. If None, then the current Axes instance is used.

**kwargsdict, optional

Any keyword arguments accepted by matplotlib.pyplot.fill_between.

Returns:

linesmatplotlib.collections.PolyCollection

A PolyCollection containing the plotted polygons.

unnormalize()

Unnormalize the profile back to the original state before any calls to normalize.