speasy.products.variable module

class speasy.products.variable.SpeasyVariable(axes: List[VariableAxis], values: DataContainer, columns: List[str] | None = None)

Bases: SpeasyProduct

SpeasyVariable object. Base class for storing variable data.

Attributes:

time: numpy.ndarray

time vector (x-axis data)

values: numpy.ndarray

data

meta: Optional[dict]

metadata

columns: Optional[List[str]]

column names, might be empty for spectrograms or 3D+ data

axes: List[np.ndarray]

Collection composed of time axis plus eventual additional axes according to values’ shape

axes_labels: List[str]

Axes names

unit: str

Values physical unit

name: str

SpeasyVariable name

nbytes: int

memory usage in bytes

Methods

view:	Returns a view of the current variable within the desired index_range
to_dataframe:	Converts the variable to a pandas.DataFrame object
from_dataframe:	Builds a SpeasyVariable from a pandas.DataFrame object
to_astropy_table:	Converts the variable to an astropy.table.Table
unit_applied:	Returns a copy where values are astropy.units.Quantity
filter_columns:	Returns a copy only containing selected columns
replace_fillval_by_nan:	Returns a SpeasyVaraible with NaN instead of fill value if fill value is set in meta data
plot:	Plot the data with matplotlib by default
to_dictionary:	Converts a SpeasyVariable to a Python dictionary, mostly used for serialization purposes
copy:	Returns a copy

property axes: List[VariableTimeAxis]

SpeasyVariable axes, axis 0 is always a VariableTimeAxis, there should be the same number of axes than values dimensions

Returns:

List[VariableTimeAxis or VariableAxis]

list of variable axes

property axes_labels: List[str]

Axes names respecting axes order

Returns:

List[str]

list of axes names

property columns: List[str]

SpeasyVariable columns names when it makes sense

Returns:

List[str]

list of columns names

copy() → SpeasyVariable

Makes a deep copy the variable

Returns:

SpeasyVariable

deep copy the variable

filter_columns(columns: List[str]) → SpeasyVariable

Builds a SpeasyVariable with only selected columns

Parameters:

columnsList[str]

list of column names to keep

Returns:

SpeasyVariable

a SpeasyVariable with only selected columns

static from_dataframe(df: DataFrame) → SpeasyVariable

Load from pandas.DataFrame object.

Parameters:

df: pandas.DataFrame

Input DataFrame to convert

Returns:

SpeasyVariable:

Variable created from DataFrame

See also

to_dataframe

exports a SpeasyVariable to a pandas DataFrame

to_astropy_table

exports a SpeasyVariable to an astropy.Table object

static from_dictionary(dictionary: Dict[str, object]) → SpeasyVariable

Builds a SpeasyVariable from a well formed dictionary

Returns:

SpeasyVariable or None

See also

to_dictionary

exports SpeasyVariable to dictionary

property meta: Dict

SpeasyVariable meta-data

Returns:

Dict

SpeasyVariable meta-data

property name: str

SpeasyVariable name

Returns:

str

SpeasyVariable name

property nbytes: int

SpeasyVariable’s values and axes memory usage

Returns:

int

number of bytes used to store values and axes

property plot

Plot the variable, tries to do its best to detect variable type and to populate plot labels

replace_fillval_by_nan(inplace=False) → SpeasyVariable

Replaces fill values by NaN, non float values are automatically converted to float. Fill value is taken from metadata field “FILLVAL”

Parameters:

inplacebool, optional

Modifies source variable when true else modifies and returns a copy, by default False

Returns:

SpeasyVariable

source variable or copy with fill values replaced by NaN

static reserve_like(other: SpeasyVariable, length: int = 0) → SpeasyVariable

Create a SpeasyVariable of given length and with the same properties than given variable but unset values

Parameters:

otherSpeasyVariable

variable used as reference for shape and meta-data

lengthint, optional

output variable length, by default 0

Returns:

SpeasyVariable

a SpeasyVariable similar to given one of given length

property time: array

Time axis values, equivalent to var.axes[0].values

Returns:

np.array

time axis values as numpy array of datetime64[ns]

to_astropy_table() → Table

Convert the variable to an astropy.Table object.

Parameters:

datetime_index: bool

boolean indicating that the index is datetime

Returns:

astropy.Table:

Variable converted to astropy.Table

See also

from_dataframe

builds a SpeasyVariable from a pandas DataFrame

to_dataframe

exports a SpeasyVariable to a pandas DataFrame

to_dataframe() → DataFrame

Convert the variable to a pandas.DataFrame object.

Returns:

pandas.DataFrame:

Variable converted to Pandas DataFrame

See also

from_dataframe

builds a SpeasyVariable from a pandas DataFrame

to_astropy_table

exports a SpeasyVariable to an astropy.Table object

to_dictionary(array_to_list=False) → Dict[str, object]

Converts SpeasyVariable to dictionary

Parameters:

array_to_listbool, optional

Converts numpy arrays to Python Lists when true, by default False

Returns:

Dict[str, object]

See also

from_dictionary

builds variable from dictionary

property unit: str

SpeasyVariable unit if found in meta-data

Returns:

str

unit if found in meta-data

unit_applied(unit: str | None = None, copy=True) → SpeasyVariable

Returns a SpeasyVariable with given or automatically found unit applied to values

Parameters:

unitstr or None, optional

Use given unit or gets one from variable metadata, by default None

copybool, optional

Preserves source variable and returns a modified copy if true, by default True

Returns:

SpeasyVariable

SpeasyVariable identic to source one with values converted to astropy.units.Quantity according to given or found unit

See also

unit

returns variable unit if found in meta-data

property values: array

SpeasyVariable values

Returns:

np.array

SpeasyVariable values

view(index_range: slice) → SpeasyVariable

Return view of the current variable within the desired index_range.

Parameters:

index_range: slice

index range

Returns:

speasy.common.variable.SpeasyVariable

view of the variable on the given range

speasy.products.variable.from_dataframe(df: DataFrame) → SpeasyVariable

Convert a dataframe to SpeasyVariable.

See also

SpeasyVariable.from_dataframe

speasy.products.variable.from_dictionary(dictionary: Dict[str, object]) → SpeasyVariable

speasy.products.variable.merge(variables: List[SpeasyVariable]) → SpeasyVariable | None

Merge a list of SpeasyVariable objects.

Parameters:

variables: List[SpeasyVariable]

Variables to merge together

Returns:

SpeasyVariable:

Resulting variable from merge operation

speasy.products.variable.to_dataframe(var: SpeasyVariable) → DataFrame

Convert a SpeasyVariable to pandas.DataFrame.

See also

SpeasyVariable.to_dataframe

speasy.products.variable.to_dictionary(var: SpeasyVariable, array_to_list=False) → Dict[str, object]