survey.core

survey.core#

This module defines the BaseSurvey base class, providing the core data structure and shared methods for all survey types.

class skysurvey.survey.core.BaseSurvey(data)[source]#

Bases: object

The BaseSurvey class.

Parameters:

  • data (pandas.DataFrame) – observing data.

  • REQUIRED_COLUMNS (list) –

    List of column names that must be present in the input DataFrame:

    • mjd: Modified Julian Date of the observation.

    • band: Filter/bandpass used (e.g., ‘g’, ‘r’, ‘i’).

    • skynoise: Image background contribution to flux error.

    • gain: CCD gain (e.g., electrons/ADU).

    • zp: Photometric zeropoint.

set_data(data, lower_precision=True, sort_mjd=True)[source]#

Set the observing data.

= It is unlikely you need to use that directly. =

Parameters:

  • data (pandas.DataFrame) – observing data. see REQUIRED_COLUMNS for the list of required columns.

  • lower_precision (bool) – change the types from 64 to 32 precision when possible.

  • sort_mjd (bool) – should this sort by mjd (if needed) as required to draw dataset

Return type:

None

get_timerange(timekey='mjd')[source]#

Returns the min and max of the given timekey column.

Parameters:

timekey (str) – column name of the time column.

Return type:

numpy.array

get_fieldcoverage(incl_zeros=False, fillna=nan, **kwargs)[source]#

Short cut to get_fieldstat('size').

Parameters:

  • incl_zeros (bool) – fields will no entries will not be shown except if incl_zeros is True

  • fillna (float, str) – format of the N/A entries

  • get_fieldstat() (**kwargs goes to)

Returns:

following groupby.agg()

Return type:

DataFrame or Serie

See also

get_fieldstat: get observing statistics for the fields

get_fieldstat(stat, columns=None, incl_zeros=False, fillna=nan, data=None)[source]#

Get observing statistics for the fields.

basically a shortcut to data.groupby("fieldid")[`column`].`stat`()

Parameters:

  • stat (str, list) – element to be passed to groupby.agg() could be e.g.: ‘mean’ or [‘mean’, ‘std’] or [np.median, ‘mean’] etc. If stat = ‘size’, this returns data[“fieldid”].value_counts() (slightly faster than groupby(“fieldid”).size()).

  • columns (str, list, None) – name of the columns to be kept. None means no cut.

  • incl_zeros (bool) – fields will no entries will not be shown except if incl_zeros is True

  • fillna (float, str) – format of the N/A entries

  • data (pandas.DataFrame, None) – data you want this to be applied to. if None, a copy of self.data is used. = leave to None if unsure =

Returns:

following groupby.agg()

Return type:

DataFrame or Serie

radec_to_fieldid(radec)[source]#

Get the fieldid of the given (list of) coordinates.

Parameters:

radec (pandas.DataFrame or 2d array) – coordinates in degree

Return type:

pandas.Series

get_observations_from_coords(radec)[source]#

Returns the data associated to the input radec coordinates.

(calls radec_to_fieldid and select data matching the fieldid)

Parameters:

radec (pandas.DataFrame or 2d array) – coordinates in degree (see format radec_to_fieldid())

Returns:

copy of the data observed in the given radec coordinates

Return type:

pandas.DataFrame

show()[source]#

Shows the sky coverage.

Raises:

NotImplementedError – This method is not implemented for this survey.

show_nexposures(ax=None, exposure_key='expid', bands=None, perband=True, band_key='band', band_colors=None, fieldid=None, legend=True, **kwargs)[source]#

Show the number of exposures per day.

Parameters:

  • ax (matplotlib.axes) – axes to plot on.

  • exposure_key (str) – column name of the exposure id.

  • bands (list) – list of bands to plot.

  • perband (bool) – if True, plot the number of exposures per band.

  • band_key (str) – column name of the band.

  • band_colors (dict) – dictionary of colors for each band.

  • fieldid (int or list) – field id to plot.

  • legend (bool) – if True, show the legend.

  • ax.bar (**kwargs goes to)

Return type:

matplotlib.figure

property data#

Dataframe containing what has been observed when. aka. the observing data

property metadata#

Metadata associated to the survey,

property nfields#

Number of fields

property fields#

Geodataframe containing the fields coordinates.

property of_type#

Kind of survey that is.

property date_range#

First and last date of the survey.