tisane.AtMost

class tisane.AtMost(value)

Bases: tisane.variable.NumberValue

An upper bound of a number of instances

Used to represent when the number of instances of a data variable has a ceiling. Should be given to the number_of_instances parameter of Unit.nominal(), Unit.numeric(), or Unit.ordinal().

Parameters

value (int or AbstractVariable) – The value of the upper bound. If an tisane.variable.AbstractVariable, then the cardinality of value is used as the upper bound.

Examples

A study using MTurkers allowed the MTurkers to participate in the study at most 20 times.

>>> import tisane as ts
>>> mturker = ts.Unit(name="mturker_id")
>>> response = mturker.ordinal(name="response", number_of_instances=AtMost(20))

Methods

per([cardinality, number_of_instances])

Express a per relationship on a given AtMost

get_value
is_equal_to_one
is_greater_than_one

per(cardinality=None, number_of_instances=None)

Express a per relationship on a given AtMost

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 use

• number_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.Exactly.per

create a per relationship with an exact multiplier

Examples

Suppose we have a within-subjects study where participants are subjected to two conditions and can memorize a list of numbers at most five times in both conditions, before being tested.

>>> import tisane as ts
>>> from tisane import AtMost
>>> participant = ts.Unit(name="participant")
>>> condition = participant.nominal(name="condition",
...                                 cardinality=2,
...                                 number_of_instances=2)
>>> memorization_session_time = participant.numeric(
...                    name="learning_session_time",
...                    number_of_instances=AtMost(5).per(
...                              number_of_instances=condition))

>>> import tisane as ts
>>> variable = ts.Unit(name="variable", cardinality=5)
>>> atmost_five_per_variable = ts.AtMost(5).per(cardinality=variable)
>>> atmost_five_per_variable.value # this should be 5 * (cardinality of variable = 5)
25

tisane.Exactly.per tisane.AtMost.per