cf.Data.maximum_absolute_value¶

Data.
maximum_absolute_value
(axes=None, squeeze=False, mtol=1, split_every=None, inplace=False)[source]¶ Calculate maximum absolute values.
Calculates the maximum absolute value or the maximum absolute values along axes.
See https://ncascms.github.io/cfpython/analysis.html#collapsemethods for mathematical definitions.
..seealso::
sample_size
,max
,minimum_absolute_value
 Parameters
 axes: (sequence of)
int
, optional The axes to be collapsed. By default all axes are collapsed, resulting in output with size 1. Each axis is identified by its integer position. If axes is an empty sequence then the collapse is applied to each scalar element and the result has the same shape as the input data.
 squeeze:
bool
, optional By default, the axes which are collapsed are left in the result as dimensions with size one, so that the result will broadcast correctly against the input array. If set to True then collapsed axes are removed from the data.
 mtol: number, optional
The sample size threshold below which collapsed values are set to missing data. It is defined as a fraction (between 0 and 1 inclusive) of the contributing input data values.
The default of mtol is 1, meaning that a missing datum in the output array occurs whenever all of its contributing input array elements are missing data.
For other values, a missing datum in the output array occurs whenever more than
100*mtol%
of its contributing input array elements are missing data.Note that for nonzero values of mtol, different collapsed elements may have different sample sizes, depending on the distribution of missing data in the input data.
 split_every:
int
ordict
, optional Determines the depth of the recursive aggregation. If set to or more than the number of input chunks, the aggregation will be performed in two steps, one partial collapse per input chunk and a single aggregation at the end. If set to less than that, an intermediate aggregation step will be used, so that any of the intermediate or final aggregation steps operates on no more than
split_every
inputs. The depth of the aggregation graph will be \(log_{split_every}(input chunks along reduced axes)\). Setting to a low value can reduce cache size and network transfers, at the cost of more CPU and a larger dask graph.By default,
dask
heuristically decides on a good value. A default can also be set globally with thesplit_every
key indask.config
. Seedask.array.reduction
for details.New in version 3.14.0.
 inplace:
bool
, optional If True then do the operation inplace and return
None
. i: deprecated at version 3.0.0
Use the inplace parameter instead.
 axes: (sequence of)
 Returns
Examples
>>> a = np.ma.arange(12).reshape(4, 3) >>> d = cf.Data(a, 'K') >>> d[1, 1] = cf.masked >>> print(d.array) [[99 1 2] [3  5] [6 7 8] [9 10 11]] >>> d.maximum_absolute_value() <CF Data(1, 1): [[99]] K>