Restrict the Domain X25677

Statement

Write a function $restrict\_domain$ that receives a function operating on floats $f$ , a lower bound $lb$ and an upper bound $ub$ . Then, $restrict\_domain$ returns a new function that operates exactly as $f$ within the closed interval $[lb, ub]$ . Outside that interval, the function produced returns $float("-inf")$.

Sample session

>>> from math import sqrt
>>> f = restrict_domain(sqrt, 1, 100)
>>> f(25)
5.0
>>> f(-25)
-inf
>>> f(125)
-inf
>>> f(1)
1.0
>>> f(100)
10.0
>>> f = restrict_domain(lambda x: x * (x+1), 10, 12)
>>> f(9)
-inf
>>> f(10)
110.0
>>> f(11)
132.0
>>> f(12)
156.0
>>> f(13)
-inf

Information

Author: Jordi Delgado and José Luis Balcázar
Language: English
Official solutions: Python
User solutions: Python