Exceedance¶

Probability that a variable exceeds (or stays below) a threshold, optionally requiring the condition to persist for a minimum duration.

`exceedance`¶

Probability that values are ≥ threshold (and ≤ maxval when set).

Parameter	Type	Default	Description
`threshold`	float	—	Lower bound for exceedance.
`maxval`	float	`inf`	Upper bound.
`inclusive`	bool	`true`	Use `>=` instead of `>`.
`duration`	str or list[str]	`"0h"`	Minimum continuous duration the condition must hold.
`group`	str	`null`	Time grouping (`month`, `season`, `year`).

When duration is a list the output includes a duration dimension.

Output variable names are suffixed with the threshold value, e.g. hs_2 for threshold 2.

- func: exceedance
  dim: time
  data_vars: [hs]
  threshold: 2.5
  duration: 1d          # must persist ≥ 1 day

- func: exceedance
  dim: time
  data_vars: [hs]
  threshold: 4.0
  duration: [12h, 1d, 3d]   # multiple durations → 'duration' dimension
  group: year

`nonexceedance`¶

Probability that values are ≤ threshold.

Parameter	Type	Default	Description
`threshold`	float	—	Upper bound.
`inclusive`	bool	`true`	Use `<=` instead of `<`.
`duration`	str or list[str]	`"0h"`	Minimum continuous duration.
`group`	str	`null`	Time grouping.

- func: nonexceedance
  dim: time
  data_vars: [hs]
  threshold: 1.0
  duration: 3d

Duration format¶

Duration strings use pandas Timedelta notation:

String	Meaning
`"0h"`	No duration filtering (simple fraction of time steps)
`"6h"`	6 hours
`"1d"`	1 day
`"7d"`	1 week

API reference¶

`gridstats.ops.exceedance.exceedance(data: xr.Dataset, *, dim: str = 'time', threshold: float, maxval: float = np.inf, inclusive: bool = True, duration: str | list[str] = '0h', group: str | None = None, **kwargs) -> xr.Dataset` ¶

Probability of exceedance above a threshold.

Parameters:

Name	Type	Description	Default
`data`	`Dataset`	Input dataset.	required
`dim`	`str`	Time dimension name.	`'time'`
`threshold`	`float`	Lower bound for exceedance.	required
`maxval`	`float`	Upper bound (default: no upper bound).	`inf`
`inclusive`	`bool`	Whether the threshold comparison is inclusive (>=).	`True`
`duration`	`str \| list[str]`	Minimum duration the condition must persist. Accepts a string like '3h' or '1d', or a list of strings for multiple durations.	`'0h'`
`group`	`str \| None`	Time component to group by (e.g. 'month', 'year').	`None`

Returns:

Type	Description
`Dataset`	Dataset with exceedance probabilities. Variable names are suffixed
`Dataset`	with the threshold value.

`gridstats.ops.exceedance.nonexceedance(data: xr.Dataset, *, dim: str = 'time', threshold: float, inclusive: bool = True, duration: str | list[str] = '0h', group: str | None = None, **kwargs) -> xr.Dataset` ¶

Probability of non-exceedance below a threshold.

Parameters:

Name	Type	Description	Default
`data`	`Dataset`	Input dataset.	required
`dim`	`str`	Time dimension name.	`'time'`
`threshold`	`float`	Upper bound for non-exceedance.	required
`inclusive`	`bool`	Whether the comparison is inclusive (<=).	`True`
`duration`	`str \| list[str]`	Minimum duration the condition must persist.	`'0h'`
`group`	`str \| None`	Time component to group by (e.g. 'month', 'year').	`None`

Returns:

Type	Description
`Dataset`	Dataset with non-exceedance probabilities. Variable names are suffixed
`Dataset`	with the threshold value.

Exceedance¶

exceedance¶

nonexceedance¶