FakeReader

class delphinus.phottable.FakeReader(filepath, nImages, refImagePath=None)

Bases: delphinus.phottable.BasePhotReader

Read Dolphot’s .fake artificial star output.

Attributes Summary

N_FAKE_GLOBAL_COLS	int(x[, base]) -> integer
N_FAKE_IMAGE_COLS	int(x[, base]) -> integer

Methods Summary

combine_structured_array()	docstring for combine_structured_array
completeness(n[, mag_err_lim, dx_lim, frac, ...])	Returns magnitude vs completeness fraction for the given image.
completeness_limit_for_image(n[, ...])	Compute the completeness limit against each a single image.
completeness_limits([mag_err_lim, dx_lim, ...])	Compute the completeness limit against each image.
export_for_starfish(output_path)	Export artificial star test data for the StarFISH synth command.
extract_additional_columns(data, nImages, nStars)	Reads additional columns for .fake output.
mag_errors()	Compute output-input magnitude difference for AST.
metrics(magRange, n[, magErrLim, dxLim])	Makes scalar metrics of artificial stars in an image.
position_errors([magIndex])	Prototype for computing position errors for AST as the Euclidean distance between input and output (x,y) coordinates.
recovered([mag_err_lim, dx_lim])	Generates a boolean array indicating if each star is recovered or not.
recovered_in_image(n[, mag_err_lim, dx_lim])	Generates a boolean array indicating if each star is recovered in the given image (n) or not.

Attributes Documentation

N_FAKE_GLOBAL_COLS = 4

N_FAKE_IMAGE_COLS = 2

Methods Documentation

combine_structured_array()

docstring for combine_structured_array

completeness(n, mag_err_lim=None, dx_lim=None, frac=0.5, dmag=0.1)

Returns magnitude vs completeness fraction for the given image.

Parameters :

n : int

Index of image to compute completeness limit for.

mag_err_lim : float

Maximum absolute difference in magnitudes, in any band, for the star to be considered recovered.

dx_lim : float

Maximum distance between a fake star’s input site and its observed site for the fake star to be considered recovered.

frac : float

Scalar fractional level of completeness. For example, 0.5 is the 50% completeness limit.

dmag : float

Bin width (magnitudes) in histogram when establishing completeness per bin.

completeness_limit_for_image(n, mag_err_lim=None, dx_lim=None, frac=0.5, dmag=0.1)

Compute the completeness limit against each a single image.

Parameters :

n : int

Index of image to compute completeness limit for.

mag_err_lim : float

Maximum absolute difference in magnitudes, in any band, for the star to be considered recovered.

dx_lim : float

Maximum distance between a fake star’s input site and its observed site for the fake star to be considered recovered.

frac : float

Scalar fractional level of completeness. For example, 0.5 is the 50% completeness limit.

dmag : float

Bin width (magnitudes) in histogram when establishing completeness per bin.

completeness_limits(mag_err_lim=None, dx_lim=None, frac=0.5, dmag=0.1)

Compute the completeness limit against each image. Returns a list of completeness limits corresponding to each image.

Parameters :

mag_err_lim : float

Maximum absolute difference in magnitudes, in any band, for the star to be considered recovered.

dx_lim : float

Maximum distance between a fake star’s input site and its observed site for the fake star to be considered recovered.

frac : float

Scalar fractional level of completeness. For example, 0.5 is the 50% completeness limit.

dmag : float

Bin width (magnitudes) in histogram when establishing completeness per bin.

export_for_starfish(output_path)

Export artificial star test data for the StarFISH synth command.

Parameters :

output_path : str

Path where crowding table will be written.

extract_additional_columns(data, nImages, nStars)

Reads additional columns for .fake output.

mag_errors()

Compute output-input magnitude difference for AST.

Returns :An nImage by nStars array of output-input differences. :

metrics(magRange, n, magErrLim=None, dxLim=None)

Makes scalar metrics of artificial stars in an image.

For each image, results a tuple (RMS mag error, completeness fraction).

position_errors(magIndex=0)

Prototype for computing position errors for AST as the Euclidean distance between input and output (x,y) coordinates.

recovered(mag_err_lim=None, dx_lim=None)

Generates a boolean array indicating if each star is recovered or not. This effectively is a boolean AND of results from recovered_in_image().

A star is recovered if:

1. Recovered magnitude error in any band is less than mag_err_limit.
2. Recovered position is within dx_lim pixels of the artificial star.

and if DOLPHOT observes a star at all at the artificial star’s site.

Parameters :

mag_err_lim : float

Maximum absolute difference in magnitudes, in any band, for the star to be considered recovered.

dx_lim : float

Maximum distance between a fake star’s input site and its observed site for the fake star to be considered recovered.

recovered_in_image(n, mag_err_lim=None, dx_lim=None)

Generates a boolean array indicating if each star is recovered in the given image (n) or not.

A star is recovered if:

1. Recovered magnitude error in any band is less than mag_err_limit.
2. Recovered position is within dx_lim pixels of the artificial star.

and if DOLPHOT observes a star at all at the artificial star’s site.

Parameters :

n : int

Index of image.

mag_err_lim : float

Maximum absolute difference in magnitudes, in any band, for the star to be considered recovered.

dx_lim : float

Maximum distance between a fake star’s input site and its observed site for the fake star to be considered recovered.