pds4_tools.reader.data module

Classes

PDS_array A factory and helper class to work with PDS_ndarray and PDS_marray.
PDS_ndarray PDS ndarray, enabling some record array functionality and having a meta_data attribute.
PDS_marray PDS masked array, enabling some record array functionality and having a meta_data attribute.

Details

class PDS_array[source]

Bases: object

A factory and helper class to work with PDS_ndarray and PDS_marray.

Intended such that PDS_ndarray and PDS_marray never need to be separately imported or called, and rather that all initialization and type checking should go through this helper class.

classmethod get_array(masked)[source]

Obtain a PDS array type.

Parameters:

masked : bool

If True, a PDS array class subclassing np.ma.MaskedArray is returned. Otherwise a PDS array class subclassing the regular np.ndarray is returned.
Returns:

PDS_ndarray or PDS_marray

A PDS array class. See masked.
static get_ndarray()[source]
Returns:

PDS_ndarray

A PDS array class based on np.ndarray.
static get_marray()[source]
Returns:

PDS_marray

A PDS array class based on np.ma.MaskedArray.
classmethod isinstance(input)[source]
Parameters:

input : any
Returns:

bool

True if input is an instance of PDS_ndarray or PDS_marray. False otherwise.
class PDS_ndarray[source]

Bases: numpy.ndarray

PDS ndarray, enabling some record array functionality and having a meta_data attribute.

Subclasses ndarrays such that we can provide meta data for an individual array or table field.

Inherits all Attributes from np.ndarray.

Parameters:

data : array_like

Data for the array.

meta_data : Meta_ArrayStructure or Meta_Field, optional

Meta-data for the array.

options : dict, optional

NumPy keywords to pass to the np.ndarray initializer.

Attributes

meta_data (Meta_ArrayStructure, Meta_Field or None) Meta-data for the array. Defaults to None if no meta-data was given on initialization or has been set.
copy(order=u'C')[source]

Copy the array.

Parameters:

order : {‘C’, ‘F’, ‘A’, ‘K’}, optional

Controls the memory layout of the copy. ‘C’ means C-order, ‘F’ means F-order, ‘A’ means ‘F’ if a is Fortran contiguous, ‘C’ otherwise. ‘K’ means match the layout of a as closely as possible.
Returns:

PDS_ndarray

An array with both the data and meta data copied.
field(key, val=None)[source]

Get or set data for a single field.

Parameters:

key : int or str

Key to select the field on. Either the name of the field, or its index.

val : any, optional

If given, sets the field specified by key to have value of val.
Returns:

any or None

A view of the selected field, if val is None. Otherwise returns None.
set_field(data, meta_data, name=None)[source]

Set data and meta data for a single field.

Parameters:

data : any

Data to set for the field.

meta_data : Meta_Field

Meta data to set for the field. If name is None, then the field name to set data for will be pulled from this attribute.

name : str, optional

The name of the field to set data for.
Returns:

None
class PDS_marray[source]

Bases: numpy.ma.core.MaskedArray, pds4_tools.reader.data.PDS_ndarray

PDS masked array, enabling some record array functionality and having a meta_data attribute.

Subclasses np.ma.MaskedArray such that we can provide meta data for an individual array or table field.

Inherits all Attributes from np.ma.MaskedArray.

Parameters:

data : array_like

Data for the array.

meta_data : Meta_ArrayStructure or Meta_Field, optional

Meta-data for the array.

options : dict, optional

NumPy keywords to pass to the np.ndarray initializer.

Attributes

meta_data (Meta_ArrayStructure, Meta_Field or None) Meta-data for the array. Defaults to None if no meta-data was given on initialization or has been set.
view(dtype=None, type=None, fill_value=None)[source]

Return a view of the PDS_marray data.

Subclassed to fix a NumPy bug that breaks setting fill_value when subselecting a field from a structured array.

filled(fill_value=None)[source]

Return a copy of self, with masked values filled with a given value.

Parameters:

fill_value : scalar, optional

The value to use for invalid entries. If None, the fill_value attribute of the array is used instead. Defaults to None.
Returns:

PDS_ndarray

A copy of self with invalid entries replaced by fill_value.
compressed()[source]

Return a copy of all the non-masked data as a 1-D array.

Returns:

PDS_ndarray

A new array holding the non-masked data is returned.
copy(order=u'C')[source]

Copy the array.

Parameters:

order : {‘C’, ‘F’, ‘A’, ‘K’}, optional

Controls the memory layout of the copy. ‘C’ means C-order, ‘F’ means F-order, ‘A’ means ‘F’ if a is Fortran contiguous, ‘C’ otherwise. ‘K’ means match the layout of a as closely as possible.
Returns:

PDS_marray

An array with both the data and meta data copied.
fill_value
set_fill_value(value=None)[source]

Set the filling value.

Parameters:

value : scalar, optional

A value used to fill the invalid entries of the masked array.
Returns:

None
set_field(data, meta_data, name=None)[source]

Set data and meta data for a single field.

Parameters:

data : any

Data to set for the field.

meta_data : Meta_Field

Meta data to set for the field. If name is None, then the field name to set data for will be pulled from this attribute.

name : str, optional

The name of the field to set data for.
Returns:

None