Source code for gammapy.utils.table

# Licensed under a 3-clause BSD style license - see LICENSE.rst
"""Table helper utilities."""
import numpy as np
from astropy.table import Table
from astropy.units import Quantity
from .units import standardise_unit

__all__ = [
    "hstack_columns",
    "table_from_row_data",
    "table_row_to_dict",
    "table_standardise_units_copy",
    "table_standardise_units_inplace",
]


[docs]def hstack_columns(table, table_other): """Stack the column data horizontally Parameters ---------- table : `~astropy.table.Table` Input table table_other : `~astropy.table.Table` Other input table Returns ------- stacked : `~astropy.table.Table` Stacked table """ stacked = Table() for column in table.colnames: data = np.hstack([table[column].data[0], table_other[column].data[0]]) stacked[column] = data[np.newaxis, :] return stacked
[docs]def table_standardise_units_copy(table): """Standardise units for all columns in a table in a copy. Calls `~gammapy.utils.units.standardise_unit`. Parameters ---------- table : `~astropy.table.Table` Input table (won't be modified) Returns ------- table : `~astropy.table.Table` Copy of the input table with standardised column units """ # Note: we could add an `inplace` option (or variant of this function) # See https://github.com/astropy/astropy/issues/6098 table = Table(table) return table_standardise_units_inplace(table)
[docs]def table_standardise_units_inplace(table): """Standardise units for all columns in a table in place.""" for column in table.columns.values(): if column.unit: column.unit = standardise_unit(column.unit) return table
[docs]def table_row_to_dict(row, make_quantity=True): """Make one source data dict. Parameters ---------- row : `~astropy.table.Row` Row make_quantity : bool Make quantity values for columns with units Returns ------- data : `dict` Row data """ data = {} for name, col in row.columns.items(): val = row[name] if make_quantity and col.unit: val = Quantity(val, unit=col.unit) data[name] = val return data
[docs]def table_from_row_data(rows, **kwargs): """Helper function to create table objects from row data. Works with quantities. Parameters ---------- rows : list List of row data (each row a dict) """ table = Table(**kwargs) if len(rows) == 0: return table colnames = list(rows[0].keys()) for name in colnames: coldata = [_[name] for _ in rows] if isinstance(rows[0][name], Quantity): coldata = Quantity(coldata, unit=rows[0][name].unit) table[name] = coldata return table