Data Points¶
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class
sacc.data_types.
DataPoint
(data_type, tracers, value, ignore_missing_tags=False, **tags)[source]¶ A class for a single data point (one scalar value).
Data points have a type, zero or more tracers, a value, and any arbitrary tags that are stored in a dictionary, and can be used to describe angular scales, window functions, or any arbitrary information to be attached to the data.
Data points can be automatically created and added to a Sacc object, so you don’t normally nee to manually create them.
Attributes: - data_type: str
A string, indicating the type of data point
- tracers: tuple
Tuple of strings with the names of tracers to use
- value: float
Mean value of this statistics
- tags: dict
Dictionary of further data point metadata, such as binning info, angles, etc.
Methods
from_table
(table[, lookups])Convert a table back into a list of data points. get_tag
(self, tag[, default])Get the value of the the named tag, or None if not found. to_table
(data[, lookups])Convert a list of data points to a single homogenous table -
classmethod
from_table
(table, lookups={})[source]¶ Convert a table back into a list of data points.
This method removes null values from the tags.
Parameters: - table: astropy.table.Table
A table of data containing the tracers, values, and tags
- lookups: dict
A dictionary of tags->dict showing replacements to make in the tags. Default is empty.
Returns: - data: list
list of DataPoint objects
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get_tag
(self, tag, default=None)[source]¶ Get the value of the the named tag, or None if not found.
Parameters: - tag: str
Tag to find on the data point
- default: any
Value to return if the tag is not found
Returns: - value: any
Value of the tag in this data point
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classmethod
to_table
(data, lookups={})[source]¶ Convert a list of data points to a single homogenous table
Since data points can have varying tags, this method uses null values to represent non-present tags.
Parameters: - data: list
A list of DataPoint objects
- lookups: dict
A dictionary of tags->dict showing replacements to make in the tags. Default is empty.
Returns: - table: astropy.table.Table
table object containing data points