Final Interval Width

Problem

Return the width of the final arithmetic coding interval for a sequence, which is the product of the symbol probabilities: prod(p_i). A long sequence therefore narrows the interval exponentially.

Hint

The interval width equals the probability of the whole sequence.

Test cases

case 1

in: [[0.5,0.5]]

expected: 0.25

case 2

in: [[0.5,0.25,0.25]]

expected: 0.03125

case 3

in: [[1]]

expected: 1

case 4

in: [[0.1,0.2,0.3]]

expected: 0.006000000000000001

Starter codePython

def interval_width(probs):
    # Your code here
    pass

4 test cases · run your code against them in the editor