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relationalai.std.math.exp()

exp(value: Number|Producer) -> Expression

Calculates the exponential of value, or e ** value, where e is the base of the natural logarithm. If value is a Producer, exp() acts as a filter and removes any non-numeric values from the producer. Must be called in a rule or query context.

Parameters

Name	Type	Description
`value`	`Producer` or Python `Number` object	The exponent to raise `e` to.

Returns

An Expression object.

Example

Use exp() to calculate the exponential of a number:

import relationalai as rai
from relationalai.std import math


# =====
# SETUP
# =====

model = rai.Model("MyModel")
Account = model.Type("Account")

with model.rule():
    Account.add(id=1).set(balance=1.0)
    Account.add(id=2).set(balance=2.0)
    Account.add(id=3).set(balance="INVALID")  # Non-numeric balance


# =======
# EXAMPLE
# =======

# Set a balance_exp property to the exponential of each account's balance.
with model.rule():
    account = Account()
    account.set(balance_exp=math.exp(account.balance))

# Since exp() filters out non-numeric values, the balance_exp property
# is not set for the account with ID 3.
with model.query() as select:
    account = Account()
    response = select(account.id, account.balance_exp)

print(response.results)
#    id  balance_exp
# 0   1     2.718282
# 1   2     7.389056
# 2   3           NaN

See Also