scopesim.utils module

Helper functions for ScopeSim.

scopesim.utils.add_keyword(filename, keyword, value, comment='', ext=0)

Add a keyword, value pair to an extension header in a FITS file.

Parameters:

filenamestr

Name of the FITS file to add the keyword to

keywordstr

valuestr, float, int

commentstr

extint, optional

The fits extension index where the keyword should be added. Default is 0

scopesim.utils.add_mags(mags)

Return a combined magnitude for a group of py_objects with mags.

scopesim.utils.airmass2zendist(airmass)

Convert airmass to zenith distance.

Parameters:

airmassfloat (>= 1)

Returns:

zenith distance in degrees

scopesim.utils.airmass_to_zenith_dist(airmass)

Return zenith distance in degrees.

Z = arccos(1/X)

scopesim.utils.angle_in_arcseconds(distance, width)

Return the angular distance of an object in arcseconds.

Units must be consistent!

scopesim.utils.bug_report() → None

Print versions of dependencies for inclusion in bug report.

scopesim.utils.bug_report_to_file(filename) → None

Like bug_report, but writes to file instead of printing.

scopesim.utils.change_table_entry(tbl, col_name, new_val, old_val=None, position=None)

scopesim.utils.check_keys(input_dict, required_keys, action='error', all_any='all')

Check to see if all/any of the required keys are present in a dict.

scopesim.utils.clean_dict(orig_dict, new_entries)

Replace OBS_DICT keywords with actual values.

Parameters:

orig_dictdict

new_entriesdict

OBS dict

Returns:

orig_dictdict

Updated dict

scopesim.utils.close_loop(*close_loop(zip(x, y)))

scopesim.utils.convert_table_comments_to_dict(tbl)

scopesim.utils.deg2rad(theta)

scopesim.utils.deriv_polynomial2d(poly)

Derive (gradient) of a Polynomial2D model.

Parameters:

polyastropy.modeling.models.Polynomial2D

Returns:

gradienttuple of Polynomial2d

scopesim.utils.dist_mod_from_distance(d)

Use mu = 5 * np.log10(d) - 5 formula.

scopesim.utils.distance_from_dist_mod(mu)

Use d = 10**(1 + mu / 5) formula.

scopesim.utils.empty_type(x)

scopesim.utils.extract_base_from_unit(unit, base_unit)

Extract astropy base unit from a compound unit.

Parameters:

unitastropy.Unit

base_unitUnit, str

Returns:

new_unitUnit

The input unit minus any base units corresponding to base_unit.

extracted_unitsUnit

Any base units corresponding to base_unit.

scopesim.utils.extract_type_from_unit(unit, unit_type)

Extract astropy physical type from a compound unit.

Parameters:

unitastropy.Unit

unit_typestr

The physical type of the unit as given by astropy

Returns:

new_unitUnit

The input unit minus any base units corresponding to unit_type.

extracted_unitsUnit

Any base units corresponding to unit_type.

scopesim.utils.figure_factory(nrows=1, ncols=1, **kwargs)

Default way to init fig and ax, to easily modify later.

scopesim.utils.figure_grid_factory(nrows=1, ncols=1, **kwargs)

Gridspec variant.

scopesim.utils.find_file(filename, path=None, silent=False)

Find a file in search path.

Parameters:

filenamestr

name of a file to look for

pathlist

list of directories to search (default: [‘./’])

silentbool

if True, remain silent when file is not found

Returns:

Absolute path of the file

scopesim.utils.from_currsys(item, cmds=None)

Return the current value of a bang-string from rc.__currsys__.

scopesim.utils.from_rc_config(item)

scopesim.utils.get_fits_type(filename)

scopesim.utils.get_meta_quantity(meta_dict, name, fallback_unit='')

Extract a Quantity from a dictionary.

Parameters:

meta_dictdict

namestr

fallback_unitQuantity

Returns:

quantQuantity

scopesim.utils.has_needed_keywords(header, suffix='')

Check to see if the WCS keywords are in the header.

scopesim.utils.insert_into_ordereddict(dic, new_entry, pos)

scopesim.utils.interp2(x_new, x_orig, y_orig)

Check and correct for decreasing x_orig values.

scopesim.utils.is_fits(filename) → bool

scopesim.utils.log_bug_report(level=10) → None

Emit bug report as logging message.

scopesim.utils.log_to_file(enable=True)

Enable or disable logging to file (convenience function).

scopesim.utils.moffat(r, alpha, beta)

!!Unfinished!! Return a Moffat function.

Parameters:

r

alpha

beta

Returns:

eta

scopesim.utils.nearest(arr, val)

Return the index of the value from arr which is closest to val.

Parameters:

arrnp.ndarray, list, tuple

Array to be searched

valfloat, int

Value to find in arr

Returns:

iint

index of array where the nearest value to val is

scopesim.utils.parallactic_angle(ha, de, lat=-24.589167)

Compute the parallactic angle.

Parameters:

hafloat

[hours] hour angle of target point

defloat

[deg] declination of target point

latfloat

[deg] latitude of observatory, defaults to Armazones

Returns:

parangfloat

The parallactic angle

Notes

The parallactic angle is defined as the angle PTZ, where P is the .. math:: taneta = frac{cosphisin H}{sinphi cosdelta - cosphi sindelta cos H} It is negative (positive) if target point is east (west) of the meridian.

References

18. Ball: “A Treatise on Spherical Astronomy”, Cambridge 1908

scopesim.utils.poissonify(arr)

Add a realisation of the poisson process to the array arr.

Parameters:

arrnp.ndarray

The input array which needs a Poisson distribution applied to items

Returns:

arrnp.ndarray

The input array, but with every pixel altered according to a poisson distribution

scopesim.utils.power_vector(val, degree)

Return the vector of powers of val up to a degree.

scopesim.utils.pretty_print_dict(dic, indent=0)

scopesim.utils.quantify(item, unit, cmds=None)

Ensure an item is a Quantity.

Parameters:

itemint, float, array, list, Quantity

unitstr, Unit

Returns:

quantQuantity

scopesim.utils.quantity_from_table(colname: str, table: Table, default_unit: str = '') → Quantity

scopesim.utils.rad2deg(theta)

scopesim.utils.real_colname(name, colnames, silent=True)

scopesim.utils.return_latest_github_actions_jobs_status(owner_name='AstarVienna', repo_name='ScopeSim', branch='dev_master', actions_yaml_name='tests.yml')

Get the status of the latest test run.

scopesim.utils.seq(start, stop, step=1)

Replacement for numpy.arange modelled after R’s seq function.

Returns an evenly spaced sequence from start to stop. stop is included if the difference between start and stop is an integer multiple of step.

From the documentation of numpy.range: “When using a non-integer step, such as 0.1, the results will often not be consistent.” This replacement aims to avoid these inconsistencies.

Parameters:

start, stop: [int, float]

the starting and (maximal) end values of the sequence.

step[int, float]

increment of the sequence, defaults to 1

scopesim.utils.set_console_log_level(level='INFO')

Set the level for the console handler (convenience function).

This controls what is actually printed to the console by ScopeSim. Accepted values are: DEBUG, INFO (default), WARNING, ERROR and CRITICAL.

scopesim.utils.stringify_dict(dic, ignore_types=(<class 'str'>, <class 'int'>, <class 'float'>))

Turn a dict entries into strings for addition to FITS headers.

scopesim.utils.telescope_diffraction_limit(aperture_size, wavelength, distance=None)

Return the diffraction limit of a telescope.

Parameters:

aperture_sizefloat

[m] The diameter of the primary mirror

wavelengthfloat

[um] The wavelength for diffarction

distancefloat, optional

Default is None. If distance is given, the transverse distance for the diffraction limit is returned in the same units as distance

Returns:

diff_limitfloat

[arcsec] The angular diffraction limit. If distance is not None, diff_limit is in the same units as distance

scopesim.utils.top_level_catch(func)

Catch any unhandled exceptions, log it including bug report.

scopesim.utils.transverse_distance(angle, distance)

Turn an angular distance into a proper transverse distance.

Parameters:

anglefloat

[arcsec] The on-sky angle

distancefloat

The distance to the object. Units are arbitary

Returns:

trans_distancefloat

proper transverse distance. Has the same Units as distance

scopesim.utils.unify(x, unit, length=1)

Convert all types of input to an astropy array/unit pair.

Parameters:

xint, float, np.ndarray, astropy.Quantity

The array to be turned into an astropy.Quantity

unitastropy.Quantity

The units to attach to the array

lengthint, optional

If x is a scalar, and the desired output is an array with length.

Returns:

yastropy.Quantity

scopesim.utils.unit_from_table(colname: str, table: Table, default_unit: str = '') → Unit

Look for the unit for a column based on the meta dict keyword “<col>_unit”.

scopesim.utils.update_logging(capture_warnings=True)

Reload logging configuration from rc.__config__.

scopesim.utils.write_report(text, filename=None, output=None)

Write a report string to file in latex or rst format.

scopesim.utils.zendist2airmass(zendist)

Convert zenith distance to airmass.

Parameters:

zenith distance[deg]

Zenith distance angle

Returns:

airmass in sec(z) approximation

scopesim.utils.zenith_dist_to_airmass(zenith_dist)

zenith_dist is in degrees.

X = sec(Z)