distribution module¶
Computation of tolerance intervals from a data-fitted probability distribution.
- class gemseo.uncertainty.statistics.tolerance_interval.distribution.BaseToleranceInterval(size)[source]
Bases:
object
Computation of tolerance intervals from a data-fitted probability distribution.
A
BaseToleranceInterval
(TI) is initialized from the number of samples used to estimate the parameters of the probability distribution and from the estimations of these parameters.A
BaseToleranceInterval
can be evaluated from:a coverage defining the minimum percentage of belonging to the TI, e.g. 0.90,
a level of confidence in [0,1], e.g. 0.95,
a type of interval, either ‘lower’ for lower-sided TI, ‘upper’ for upper-sided TI or ‘both’ for both-sided TI.
Note
Lower-sided tolerance intervals are used to analyse the strength of materials. They are also known as basis tolerance limits. In particular, the B-value is the lower bound of the lower-sided tolerance interval with 90%-coverage and 95%-confidence while the A-value is the lower bound of the lower-sided tolerance interval with 95%-coverage and 95%-confidence.
- Parameters:
size (int) – The number of samples.
- class Bounds(lower, upper)[source]
Bases:
NamedTuple
The component-wise bounds of a vector.
Create new instance of Bounds(lower, upper)
- lower: NDArray[float]
Alias for field number 0
- upper: NDArray[float]
Alias for field number 1
- class ToleranceIntervalSide(value)[source]
Bases:
LowercaseStrEnum
The side of the tolerance interval.
- BOTH = 'both'
- LOWER = 'lower'
- UPPER = 'upper'
- compute(coverage, confidence=0.95, side=ToleranceIntervalSide.BOTH)[source]
Compute a tolerance interval.
- Parameters:
coverage (float) – A minimum percentage of belonging to the TI.
confidence (float) –
A level of confidence in [0,1].
By default it is set to 0.95.
side (ToleranceIntervalSide) –
The type of the tolerance interval characterized by its sides of interest, either a lower-sided tolerance interval \([a, +\infty[\), an upper-sided tolerance interval \(]-\infty, b]\), or a two-sided tolerance interval \([c, d]\).
By default it is set to “both”.
- Returns:
The tolerance bounds.
- Return type: