Skip to content
nonconvexcard

Optimal clipping for a Laplace-distributed tensor

ProofAdvanced⏱ 1 hourQuantizationclippingmseoptimisationlaplace

Problem

Let XX have the Laplace density f(x)=12λe−∣x∣/λf(x) = \frac{1}{2\lambda}e^{-|x|/\lambda}, quantized with bb bits over [−A,A][-A,A].

  1. Compute the clipping term 2∫A∞(x−A)2f(x) dx2\int_A^\infty (x-A)^2 f(x)\,dx in closed form.
  2. Write the total MSE, treating P(∣X∣≤A)≈1\P(|X|\le A)\approx1, and derive the stationarity condition for the optimal AA.
  3. Solve numerically for b=4b = 4 and b=8b = 8 with λ=1\lambda = 1, and comment on how the optimal loading factor moves with bb.

Write a complete argument. Every inequality you use should be one you could state precisely.

Hints

Hints — 0 of 2 revealed

Solution

Opening this before you have a real attempt on paper is the fastest way to feel like you understand something you cannot reproduce.

Related problems

All problems
SolvedProblemFieldTypeDifficultyTime
The round-trip error boundQuantizationProofFoundation15 min
The true bit width of a group-quantized formatQuantizationNumericalFoundation15 min
Six decibels per bit, and what outliers costQuantizationNumericalBeginner30 min
The Δ²/12 noise varianceQuantizationProofBeginner15 min
Optimal checkpointing frequencyFine-TuningProofIntermediate30 min