empyrean.KeplerianCoordinates

class KeplerianCoordinates(table, **kwargs)[source]

Bases: Table

Keplerian orbital elements.

Methods

__init__(table, **kwargs)

apply_mask(mask)

Return a new table with rows filtered to match a boolean mask.

as_column([nullable, metadata])

Embed the Table as a column in another Table.

attributes()

Return a dictionary of the table's attributes.

chunk_counts()

Returns the number of discrete memory chunks that make up each of the Table's underlying arrays.

column(column_name)

Returns the column with the given name as a raw pyarrow ChunkedArray.

drop_duplicates([subset, keep])

Drop duplicate rows from a ~quivr.Table.

empty(**kwargs)

Create an empty instance of the table.

flattened_table()

Completely flatten the Table's underlying Arrow table, taking into account any nested structure, and return the data table itself.

fragmented()

Returns true if the Table has any fragmented arrays.

from_csv(input_file[, validate])

Read a table from a CSV file.

from_dataframe(df[, validate])

Load a DataFrame into the Table.

from_feather(path[, validate])

Read a table from a Feather file.

from_flat_dataframe(df[, validate])

Load a flattened DataFrame into the Table.

from_kwargs([validate, permit_nulls])

Create a Table instance from keyword arguments.

from_parquet(path[, memory_map, ...])

Read a table from a Parquet file.

from_pyarrow(table[, validate, permit_nulls])

Create a new table from a pyarrow Table.

invalid_mask()

Return a boolean mask indicating which rows are invalid.

is_valid()

Validate the table against the schema.

null_mask()

Return a boolean mask indicating which rows of the entire table are null.

nulls(size, **kwargs)

Create a table with nulls.

period_days([mu])

(N,) orbital period T = 2π√(a³/μ) [days].

select(column_name, value)

Select from the table by exact match, returning a new Table which only contains rows for which the value in column_name equals value.

separate_invalid()

Separates rows that have invalid data from those that have valid data.

set_column(name, data)

Return a copy of the table with a particular column replaced with new data.

sort_by(by)

Sorts the Table by the given column name (or multiple columns).

take(row_indices)

Return a new Table with only the rows at the given indices.

to_csv(path[, attribute_columns])

Write the table to a CSV file.

to_dataframe([flatten, attr_handling])

Returns self as a pandas DataFrame.

to_feather(path, **kwargs)

Write the table to a Feather file.

to_parquet(path, **kwargs)

Write the table to a Parquet file.

to_structarray()

Returns self as a StructArray.

unique_indices([subset, keep])

Get the indices of the first or last occurrence of each unique row in the table.

validate()

Validate the table against the schema, raising an exception if invalid.

where(expr)

Return a new table with rows filtered to match an expression.

with_table(table)

Attributes

a

A column for storing 64-bit floating point numbers.

ap

A column for storing 64-bit floating point numbers.

aphelion_au

(N,) aphelion distance Q = a(1 + e) [AU].

covariance

A column which represents an embedded quivr table.

e

A column for storing 64-bit floating point numbers.

epoch

A column for storing 64-bit floating point numbers.

frame

StringAttribute represents a string which is stored as UTF-8 bytes in Table metadata.

i

A column for storing 64-bit floating point numbers.

ma

A column for storing 64-bit floating point numbers.

origin

A column for storing large strings (over 231 bytes long).

perihelion_au

(N,) perihelion distance q = a(1 − e) [AU].

raan

A column for storing 64-bit floating point numbers.

schema

table

Parameters:
  • table (Table)

  • kwargs (AttributeValueType)

epoch

A column for storing 64-bit floating point numbers.

a

A column for storing 64-bit floating point numbers.

e

A column for storing 64-bit floating point numbers.

i

A column for storing 64-bit floating point numbers.

raan

A column for storing 64-bit floating point numbers.

ap

A column for storing 64-bit floating point numbers.

ma

A column for storing 64-bit floating point numbers.

covariance

A column which represents an embedded quivr table.

Parameters:
  • table_type – The type of the table to embed.

  • nullable – Whether the column can contain null values.

  • metadata – A dictionary of metadata to attach to the column.

frame

StringAttribute represents a string which is stored as UTF-8 bytes in Table metadata.

Parameters:

default – The default value for this attribute. If no default is provided, then the attribute must be set whenever constructing a table that uses it.

origin

A column for storing large strings (over 231 bytes long). Large string data is stored in variable-length chunks.

property perihelion_au: ndarray[Any, dtype[float64]]

(N,) perihelion distance q = a(1 − e) [AU]. Negative when a < 0 (hyperbolic), so q = a(1 e) stays positive.

property aphelion_au: ndarray[Any, dtype[float64]]

(N,) aphelion distance Q = a(1 + e) [AU]. Returns NaN for hyperbolic / parabolic orbits (e ≥ 1) where aphelion is not defined.

period_days(mu=0.00029591220828559115)[source]

(N,) orbital period T = 2π√(a³/μ) [days]. Returns NaN for hyperbolic orbits (a < 0).

Return type:

ndarray[Any, dtype[double]]

Parameters:

mu (float)

schema: ClassVar[Schema] = epoch: double not null a: double not null e: double not null i: double not null raan: double not null ap: double not null ma: double not null covariance: struct<cov_a_a: double, cov_a_e: double, cov_e_e: double, cov_a_i: double, cov_e_i: double, cov_i_i: (... 298 chars omitted)   child 0, cov_a_a: double   child 1, cov_a_e: double   child 2, cov_e_e: double   child 3, cov_a_i: double   child 4, cov_e_i: double   child 5, cov_i_i: double   child 6, cov_a_raan: double   child 7, cov_e_raan: double   child 8, cov_i_raan: double   child 9, cov_raan_raan: double   child 10, cov_a_ap: double   child 11, cov_e_ap: double   child 12, cov_i_ap: double   child 13, cov_raan_ap: double   child 14, cov_ap_ap: double   child 15, cov_a_ma: double   child 16, cov_e_ma: double   child 17, cov_i_ma: double   child 18, cov_raan_ma: double   child 19, cov_ap_ma: double   child 20, cov_ma_ma: double origin: large_string not null