epygram.formats.LFI — Interface-Class to the LFI format

Contains the class to handle LFI format.

class epygram.formats.LFI.LFI(*args, **kwargs)

Bases: epygram.resources.FileResource.FileResource

Class implementing all specificities for LFI resource format.

Note

This class is managed by footprint.

• info: Not documented
• priority: PriorityLevel::DEFAULT (rank=1)

Automatic parameters from the footprint:

• compressed (builtins.bool) - rwx - Compression flag.
  • Optional. Default is False.
• filename (builtins.str) - rxx - File name (absolute or relative) of the resource.
• fmtdelayedopen (builtins.bool) - rxx - Opening of the resource delayed (not at time of construction).
  • Optional. Default is False.
• format (builtins.str) - rxx - Format of the resource.
  • Optional. Default is ‘LFI’.
  • Values: set([‘LFI’])
• moveOnMass (builtins.bool) - rxx - If True, 3d fields are put on mass levels
  • Optional. Default is False.
• openmode (builtins.str) - rxx - Opening mode.
  • Values: set([‘append’, ‘write’, ‘w’, ‘read’, ‘r’, ‘a’])
  • Remap: dict(append = ‘a’, read = ‘r’, write = ‘w’,)
• true3d (builtins.bool) - rxx - If False, 3D fields are seen as a collection of H2D fields
  • Optional. Default is False.

close()

Closes a LFI with ifsaux’ LFIFER.

compressed

Undocumented footprint attribute

delfield(fid)

Deletes a field from file “in place”.

extract_subdomain(*args, **kwargs)

Extracts a subdomain from the LFI resource, given its fid and the geometry to use.

Parameters:

• fid – must have syntax: (‘PARAMETER’, ‘*’) if not true3d else ‘PARAMETER’, * being a true star character, and PARAMETER being the name of the parameter requested, as named in LFI.
• geometry – the geometry on which extract data. None to keep the geometry untouched.
• vertical_coordinate – defines the requested vertical coordinate of the V2DField (cf. epygram.geometries.V1DGeometry coordinate possible values).

:param interpolation defines the interpolation function used to compute

the profile points locations from the fields grid:

• if ‘nearest’, each horizontal point of the section is taken as the horizontal nearest neighboring gridpoint;
• if ‘linear’ (default), each horizontal point of the section is computed with linear spline interpolation;
• if ‘cubic’, each horizontal point of the section is computed with linear spline interpolation.

Parameters:

• exclude_extralevels – if True, not physical levels are removed
• cheap_height – has no effect (compatibity with FA format)

extractprofile(*args, **kwargs)

Extracts a vertical profile from the LFI resource, given its fid and the geographic location (lon/lat) of the profile.

Parameters:

• fid – must have syntax: (‘PARAMETER’, ‘*’) if not true3d, else ‘PARAMETER’, * being a true star character, and PARAMETER being the name of the parameter requested, as named in LFI.
• lon – the longitude of the desired point.
• lat – the latitude of the desired point.
• geometry – the geometry on which extract data. If None, it is built from lon/lat.
• vertical_coordinate – defines the requested vertical coordinate of the V1DField (cf. epygram.geometries.V1DGeometry coordinate possible values).
• interpolation –

  defines the interpolation function used to compute the profile at requested lon/lat from the fields grid:

  • if ‘nearest’ (default), extracts profile at the horizontal nearest neighboring gridpoint;
  • if ‘linear’, computes profile with horizontal linear spline interpolation;
  • if ‘cubic’, computes profile with horizontal cubic spline interpolation.
• external_distance – can be a dict containing the target point value and an external field on the same grid as self, to which the distance is computed within the 4 horizontally nearest points; e.g. {‘target_value’:4810, ‘external_field’:an_H2DField_with_same_geometry}. If so, the nearest point is selected with distance = |target_value - external_field.data|
• cheap_height – has no effect (compatibity with FA format)

extractsection(*args, **kwargs)

Extracts a vertical section from the LFI resource, given its fid and the geographic (lon/lat) coordinates of its ends. The section is returned as a V2DField.

Parameters:

• fid – must have syntax: (‘PARAMETER’, ‘*’) if not true3d else ‘PARAMETER’, * being a true star character, and PARAMETER being the name of the parameter requested, as named in LFI.
• end1 – must be a tuple (lon, lat).
• end2 – must be a tuple (lon, lat).
• geometry – the geometry on which extract data. If None, defaults to linearily spaced positions computed from points_number.
• points_number – defines the total number of horizontal points of the section (including ends). If None, defaults to a number computed from the ends and the resolution.
• resolution – defines the horizontal resolution to be given to the field. If None, defaults to the horizontal resolution of the field.
• vertical_coordinate – defines the requested vertical coordinate of the V2DField (cf. epygram.geometries.V1DGeometry coordinate possible values).
• interpolation –

  defines the interpolation function used to compute the profile points locations from the fields grid:

  • if ‘nearest’, each horizontal point of the section is taken as the horizontal nearest neighboring gridpoint;
  • if ‘linear’ (default), each horizontal point of the section is computed with linear spline interpolation;
  • if ‘cubic’, each horizontal point of the section is computed with linear spline interpolation.
• cheap_height – has no effect (compatibity with FA format)

filename

Undocumented footprint attribute

find_fields_in_resource(seed=None, fieldtype=[], generic=False)

Returns a list of the fields from resource whose identifier match the given seed.

Parameters:

• seed –

  might be:

  • a tuple of regular expressions,
  • a string meant to be converted to a tuple
  • a list of regular expressions tuples
  • None. If None (default), returns the list of all fields in resource.

  If self.true3d: tuples are replaced by string

• fieldtype – optional, among (‘H2D’, ‘Misc’) or a list of these strings. If provided, filters out the fields not of the given types.
• generic – if True, returns a list of tuples (fieldname, generic fid) of the fields.

fmtdelayedopen

Undocumented footprint attribute

format

Undocumented footprint attribute

listfields(**kwargs)

Returns a list containing the LFI identifiers of all the fields of the resource.

moveOnMass

Undocumented footprint attribute

open(openmode=None)

Opens a LFI with ifsaux’ LFIOUV, and initializes some attributes.

Parameters:openmode – optional, to open with a specific openmode, eventually different from the one specified at initialization.

openmode

Undocumented footprint attribute

readfield(*args, **kwargs)

Reads one field, given its identifier (tuple (LFI name, level)), and returns a Field instance. Interface to Fortran routines from ‘ifsaux’.

Parameters:

• fieldidentifier – “LFI fieldname” if true3d, else (LFI fieldname, level).
• getdata – optional, if False, only metadata are read, the field do not contain data. Default is True.

readfields(requestedfields=None, getdata=True)

Returns a epygram.base.FieldSet containing requested fields read in the resource.

Parameters:

• requestedfields –

  might be

  • a tuple of regular expressions (e.g. (‘RVT’, ‘?’)) or a regular expression (e.g. ‘R?T’) if true3d
  • a list of LFI fields identifiers with regular expressions (e.g. [(‘COVER???’, 0), (‘RVT’, ‘*’)])
  • if not specified, interpretated as all fields that will be found in resource
• getdata – optional, if False, only metadata are read, the fields do not contain data. Default is True.

rename_field(fid, new_fid)

Renames a field “in place”.

sortfields()

Returns a sorted list of fields with regards to their name and nature, as a dict of lists.

true3d

Undocumented footprint attribute

what(*args, **kwargs)

Writes in file a summary of the contents of the LFI.

Parameters:

• out – the output open file-like object
• sortfields – True if the fields have to be sorted by type.

writefield(field)

Write a field in the resource.

Parameters:field – a epygram.base.Field instance or epygram.H2DField.

writefields(fieldset)

Write the fields of the fieldset in the resource.

Parameters:fieldset – must be a epygram.base.FieldSet instance.