# cf.CoordinateReference.equals¶

CoordinateReference.equals(other, rtol=None, atol=None, verbose=None, ignore_type=False)[source]

Whether two coordinate reference constructs are the same.

Equality is strict by default. This means that:

• the datum and coordinate conversion components must have the same string and numerical parameters.

The dimension coordinate, auxiliary coordinate and domain ancillary constructs of the coordinate reference constructs are not considered, because they may only be correctly interpreted by the field constructs that contain the coordinate reference constructs in question. They are, however, taken into account when two fields constructs are tested for equality.

Two real numbers x and y are considered equal if |x-y|<=atol+rtol|y|, where atol (the tolerance on absolute differences) and rtol (the tolerance on relative differences) are positive, typically very small numbers. The data type of the numbers is not taken into consideration. See the atol and rtol parameters.

Any type of object may be tested but, in general, equality is only possible with another coordinate reference construct, or a subclass of one. See the ignore_type parameter.

NetCDF elements, such as netCDF variable and dimension names, do not constitute part of the CF data model and so are not checked.

New in version 1.7.0.

Parameters
other:

The object to compare for equality.

atol: float, optional

The tolerance on absolute differences between real numbers. The default value is set by the cfdm.ATOL function.

rtol: float, optional

The tolerance on relative differences between real numbers. The default value is set by the cfdm.RTOL function.

verbose: int or None, optional

If an integer from 0 to 3, corresponding to increasing verbosity (else -1 as a special case of maximal and extreme verbosity), set for the duration of the method call (only) as the minimum severity level cut-off of displayed log messages, regardless of the global configured cfdm.LOG_LEVEL.

Else, if None (the default value), log messages will be filtered out, or otherwise, according to the value of the cfdm.LOG_LEVEL setting.

Overall, the higher a non-negative integer that is set (up to a maximum of 3) the more description that is printed to convey information about differences that lead to inequality.

ignore_type: bool, optional

Any type of object may be tested but, in general, equality is only possible with another coordinate reference construct, or a subclass of one. If ignore_type is True then CoordinateReference(source=other) is tested, rather than the other defined by the other parameter.

Returns
bool

Whether the two coordinate reference constructs are equal.

Examples:

>>> c.equals(c)
True
>>> c.equals(c.copy())
True
>>> c.equals('not a coordinate reference')
False