mqr.spc.EwmaParams.

from_stddev

static EwmaParams.from_stddev(mu_0, s_bar, nobs, lmda, L, steady_state=False)

Constructs EwmaParams from an average sample stddev.

Parameters:

mu_0float

Process target mean.

s_barfloat

Average sample stddev from a reference in-control process.

nobsint

Size (fixed) of samples used to calculate (s_bar).

lmdafloat

Smoothing factor.

Lfloat

Width of the limits in multiples of the stddev of the smoothed mean.

steady_statebool, optional

Whether the process has already decayed to the steady state control limits.