Block-Wise Scale Factor

Problem

Compute the symmetric scale for a quantization block: max(|x|) / (2^(bits-1) - 1), where the denominator is the largest representable signed integer. An all-zero block gives 0.0.

The signature is block_scale_factor(block, bits=8).

Hint

Smaller blocks adapt better to local ranges but cost more scale bytes.

Test cases

case 1

in: [[-1,2,0.5],8]

expected: 0.015748031496062992

case 2

in: [[0,0],8]

expected: 0

case 3

in: [[3,-4],4]

expected: 0.5714285714285714

case 4

in: [[1.5],8]

expected: 0.011811023622047244

Starter codePython

def block_scale_factor(block, bits=8):
    # Your code here
    pass

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