tisane.variable.Exactly.per¶
method
- Exactly.per(cardinality=None, number_of_instances=None)¶
Express a per relationship on a given Exactly
Even though cardinality and number_of_instances are both optional parameters, this method requires exactly one of them to be specified – you currently cannot specify both.
- Parameters
cardinality (AbstractVariable, optional) – The
AbstractVariable
whose cardinality we want to usenumber_of_instances (AbstractVariable, optional) – The
AbstractVariable
whose number of instances we want to use
- Returns
An object representing a “_ per _” relationship.
- Return type
tisane.variable.Per
See also
tisane.AtMost.per
create a per relationship with an
AtMost
multiplier
Examples
Rats are either given a supplement or a placebo three times a day, so exactly 3 per day
>>> import tisane as ts >>> from tisane import Exactly >>> rat = ts.Unit(name="rat_id", cardinality=30) # 30 rats in the study >>> days = rat.ordinal(name="day_num", cardinality=28) # 4 weeks of data for each rat >>> memory_test_result = rat.numeric(name="memory_test_result", ... number_of_instances=days) >>> supplements = rat.nominal(name="supplement", ... categories=["placebo", "supp"], ... number_of_instances=Exactly(3).per(cardinality=days))