cf.DimensionCoordinate.create_bounds

DimensionCoordinate.create_bounds(bound=None, cellsize=None, flt=0.5, max=None, min=None)[source]

Create cell bounds.

Parameters
bound: optional

If set to a value larger (smaller) than the largest (smallest) coordinate value then bounds are created which include this value and for which each coordinate is in the centre of its bounds.

cellsize: optional

Define the exact size of each cell that is created. Created cells are allowed to overlap do not have to be contigious. The cellsize parameter may be one of:

  • A data-like scalar (see below) that defines the cell size, either in the same units as the coordinates or in the units provided. Note that in this case, the position of each coordinate within the its cell is controlled by the flt parameter.

    Parameter example:

    To specify cellsizes of 10, in the same units as the coordinates: cellsize=10.

    Parameter example:

    To specify cellsizes of 1 day: cellsize=cf.Data(1, 'day') (see cf.Data for details).

    Parameter example:

    For coordinates 1, 2, 10, setting cellsize=1 will result in bounds of (0.5, 1.5), (1.5, 2.5), (9.5, 10.5).

    Parameter example:

    For coordinates 1, 2, 10 kilometres, setting cellsize=cf.Data(5000, 'm') will result in bounds of (-1.5, 3.5), (-0.5, 4.5), (7.5, 12.5) (see cf.Data for details).

    Parameter example:

    For decreasing coordinates 2, 0, -12 setting, cellsize=2 will result in bounds of (3, 1), (1, -1), (-11, -13).

  • A cf.TimeDuration defining the cell size. Only applicable to reference time coordinates. It is possible to “anchor” the cell bounds via the cf.TimeDuration parameters. For example, to specify cell size of one calendar month, starting and ending on the 15th day: cellsize=cf.M(day=15) (see cf.M for details). Note that the flt parameter is ignored in this case.

    Parameter example:

    For coordinates 1984-12-01 12:00, 1984-12-02 12:00, 2000-04-15 12:00 setting, cellsize=cf.D() will result in bounds of (1984-12-01, 1984-12-02), (1984-12-02, 1984-12-03), (2000-05-15, 2000-04-16) (see cf.D for details).

    Parameter example:

    For coordinates 1984-12-01, 1984-12-02, 2000-04-15 setting, cellsize=cf.D() will result in bounds of (1984-12-01, 1984-12-02), (1984-12-02, 1984-12-03), (2000-05-15, 2000-04-16) (see cf.D for details).

    Parameter example:

    For coordinates 1984-12-01, 1984-12-02, 2000-04-15 setting, cellsize=cf.D(hour=12) will result in bounds of (1984-11:30 12:00, 1984-12-01 12:00), (1984-12-01 12:00, 1984-12-02 12:00), (2000-05-14 12:00, 2000-04-15 12:00) (see cf.D for details).

    Parameter example:

    For coordinates 1984-12-16 12:00, 1985-01-16 12:00 setting, cellsize=cf.M() will result in bounds of (1984-12-01, 1985-01-01), (1985-01-01, 1985-02-01) (see cf.M for details).

    Parameter example:

    For coordinates 1984-12-01 12:00, 1985-01-01 12:00 setting, cellsize=cf.M() will result in bounds of (1984-12-01, 1985-01-01), (1985-01-01, 1985-02-01) (see cf.M for details).

    Parameter example:

    For coordinates 1984-12-01 12:00, 1985-01-01 12:00 setting, cellsize=cf.M(day=20) will result in bounds of (1984-11-20, 1984-12-20), (1984-12-20, 1985-01-20) (see cf.M for details).

    Parameter example:

    For coordinates 1984-03-01, 1984-06-01 setting, cellsize=cf.Y() will result in bounds of (1984-01-01, 1985-01-01), (1984-01-01, 1985-01-01) (see cf.Y for details). Note that in this case each cell has the same bounds. This because cf.Y() is equivalent to cf.Y(month=1, day=1) and the closest 1st January to both coordinates is 1st January 1984.

{+data-like-scalar} TODO

flt: float, optional

When creating cells with sizes specified by the cellsize parameter, define the fraction of the each cell which is less its coordinate value. By default flt is 0.5, so that each cell has its coordinate at it’s centre. Ignored if cellsize is not set.

Parameter example:

For coordinates 1, 2, 10, setting cellsize=1, flt=0.5 will result in bounds of (0.5, 1.5), (1.5, 2.5), (9.5, 10.5).

Parameter example:

For coordinates 1, 2, 10, setting cellsize=1, flt=0.25 will result in bounds of (0.75, 1.75), (1.75, 2.75), (9.75, 10.75).

Parameter example:

For decreasing coordinates 2, 0, -12, setting cellsize=6, flt=0.9 will result in bounds of (2.6, -3.4), (0.6, -5.4), (-11.4, -17.4).

max: optional

Limit the created bounds to be no more than this number.

Parameter example:

To ensure that all latitude bounds are at most 90: max=90.

min: optional

Limit the created bounds to be no less than this number.

Parameter example:

To ensure that all latitude bounds are at least -90: min=-90.

Returns
Bounds

The newly-created coordinate cell bounds object.

Examples

>>> c.create_bounds()
>>> c.create_bounds(bound=-9000.0)