generate_relaxed_cand_C1: generate_relaxed_cand_C1

In queelius/masked.data: Estimating Reliability of Components in Series from Masked Data with Relaxed Candidate Set Models

generate_relaxed_cand_C1

Description

Generates a probability ⁠Q = (q1, q2, ..., qm)⁠ such that qj is the probability that the j-th component is in the candidate set, qk = 1, where k is failed component. Q is an informed candidate model that uses informative_masking_by_rank to assign higher probabilities to components that failed earlier (which is something we typically only know in, say, a simulation study).

Usage

generate_relaxed_cand_C1(
  d,
  ts,
  p,
  debug = F,
  eps = 1e-08,
  alpha0 = 1,
  beta0 = p,
  lambda = 1,
  max_iter = 10000L,
  lr = 1
)

Arguments

d	numeric, the KL divergence from P = (p, p, ..., p, 1, p, ..., p) to try to obtain
ts	component failure times for the series system
p	numeric, defines ⁠P = (p, ..., p, 1, p, ..., p)⁠.
debug	Logical, whether to output debugging information while running
eps	numeric, stopping condition.
alpha0	numeric, initial guess for alpha parameter of informative_masking_by_rank.
beta0	numeric, initial guess for beta parameter of informative_masking_by_rank.
lambda	numeric, controls how much the two constraints are weighted. Lower value specifies more enforcement of the KL-divergence constraint being closer to d. Defaults to 1.
max_iter	Integer, maximum number of iterations before giving up.
lr	numeric, learning rate.

Details

The probabilities Q have two constraints on them. Let ⁠P = (p, ..., p, 1, p, ..., p)⁠ be the bernoulli candidate model that satisfies conditions C1, C2, and C3. Then, the KL-divergence between P and Q is as close as possible to d while satisfying sum(P) == sum(Q).

For d = 0, Q == P. As d increases, Q becomes more informative about the components. Given the structure of informative_masking_by_rank, it may not be possible to satisfy every d specified, but we get as close as we can, which should permit useful experiments.

queelius/masked.data documentation built on Jan. 28, 2025, 4:23 a.m.