epygram.geometries.AcademicGeometry — Academic Geometry class

Contains the classes for 3D geometries of fields.

class epygram.geometries.AcademicGeometry.AcademicGeometry(name, grid, dimensions, vcoordinate, projection, position_on_horizontal_grid='__unknown__', geoid=None)[source]

Bases: epygram.geometries.AbstractGeometry.RectangularGridGeometry

Handles the geometry for an academic 3-Dimensions Field.

Parameters

  • name – Name of geometrical type of representation of points on the Globe. Name must be ‘academic’

  • grid – Handles description of the horizontal grid.

  • dimensions – Handles grid dimensions.

  • vcoordinate – Handles vertical geometry parameters.

  • position_on_horizontal_grid –

    Position of points w/r to the horizontal. among: [‘upper-right’, ‘upper-left’,

    ’lower-left’, ‘lower-right’, ‘center-left’, ‘center-right’, ‘lower-center’, ‘upper-center’, ‘center’, ‘__unknown__’]

  • geoid – To specify geoid shape (of no meaning in this geometry).

azimuth(end1, end2)[source]

Same as plane_azimuth in this geometry.

default_cartopy_CRS()

Note

Requires plugin: with_cartopy (config.activate_plugins)

Create a cartopy.crs appropriate to the Geometry.

In this case, cartopy is not used but raw matplotlib, so returned CRS is None.

distance(end1, end2)[source]

Computes the distance between two points along a straight line in the geometry. :param end1: must be a tuple (lon, lat) in degrees. :param end2: must be a tuple (lon, lat) in degrees.

getcenter()[source]

Returns the coordinate of the grid center as a tuple (center_lon, center_lat).

ij2ll(i, j, position=None)[source]

Return the (lon, lat) coordinates of point (i,j), in degrees.

Parameters

  • i – X index of point in the 2D matrix of gridpoints

  • j – Y index of point in the 2D matrix of gridpoints

  • position – lat lon position to return with respect to the model cell. Defaults to self.position_on_horizontal_grid.

This routine has a special meaning for this geometry. It returns the (i, j) position in the original grid (especially after a section extraction) with an offset of one (for old tools compatibility).

ij2xy(i, j, position=None)[source]

Return the (x, y) coordinates of point (i,j), in the projection.

Parameters

  • i – X index of point in the 2D matrix of gridpoints

  • j – Y index of point in the 2D matrix of gridpoints

  • position – position to return with respect to the model cell. Defaults to self.position_on_horizontal_grid.

Note that origin of coordinates in projection is the center of the C+I domain.

linspace(end1, end2, num)[source]

Returns evenly spaced points over the specified interval. Points are lined up in the geometry.

Parameters

  • end1 – must be a tuple (lon, lat) in degrees.

  • end2 – must be a tuple (lon, lat) in degrees.

  • num – number of points, including point1 and point2.

ll2ij(lon, lat, position=None)[source]

Return the (i, j) indexes of point (lon, lat) in degrees, in the 2D matrix of gridpoints.

Parameters

  • lon – longitude of point in degrees

  • lat – latitude of point in degrees

  • position – lat lon position to return with respect to the model cell. Defaults to self.position_on_horizontal_grid.

Caution: the returned (i,j) are float.

This routine has a special meaning for this geometry. It returns the (lon, lat) position in the original grid (especially after a section extraction) with an offset of one (for old tools compatibility).

ll2xy(lon, lat)[source]

Return the (x, y) coordinates of point (lon, lat) in degrees.

Parameters

  • lon – longitude of point in degrees

  • lat – latitude of point in degrees

Note that origin of coordinates in projection is the center of the C+I domain.

make_section_geometry(end1, end2, points_number=None, resolution=None, position=None)[source]

Returns a academic Geometry.

Parameters

  • end1 – must be a tuple (lon, lat) in degrees.

  • end2 – must be a tuple (lon, lat) in degrees.

  • 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.

  • position – defines the position of data in the grid (defaults to ‘center’)

plane_azimuth(end1, end2)[source]

Initial bearing from end1 to end2 points in plane local referential geometry.

Parameters

  • end1 – must be a tuple (lon, lat) in degrees.

  • end2 – must be a tuple (lon, lat) in degrees.

resolution_ij(*_, **__)[source]

Returns the minimum of X and Y resolution.

resolution_ll(*_, **__)[source]

Returns the minimum of X and Y resolution.

tolerant_equal(other, tolerance=2.220446049250313e-16)[source]

Test of equality by recursion on the object’s attributes, with a tolerance.

xy2ij(x, y, position=None)[source]

Return the (i, j) indexes of point (x, y), in the 2D matrix of gridpoints.

Parameters

  • x – X coordinate of point in the academic projection

  • y – Y coordinate of point in the academic projection

  • position – position to return with respect to the model cell. Defaults to self.position_on_horizontal_grid.

Caution: (i,j) are float (the nearest grid point is the nearest integer).

Note that origin of coordinates in projection is the center of the C+I domain.

xy2ll(x, y)[source]

Return the (lon, lat) coordinates of point (x, y) in the 2D matrix of gridpoints*(i,j)*, in degrees.

Parameters

  • x – X coordinate of point in the academic projection

  • y – Y coordinate of point in the academic projection

Note that origin of coordinates in projection is the center of the C+I domain.