Data preparation

Clean a series before analysis: fill or drop missing values, and despike outliers.

Missing data

Filling and removing NaN values.

Function	Description
Dropna	Drop events whose value is NaN.
Forward-fill NaNs	Replace NaN with the most recent finite value.
Replace NaNs with a constant	Replace NaN with a user-specified scalar.
IsFinite	Returns 1.0 for finite values, 0.0 for NaN or inf. Does not propagate NaN.
IsNan	Returns 1.0 if the input is NaN, else 0.0. Does not propagate NaN.

Outliers & robustness

Despiking and robust estimators.

Function	Description
Clip to bounds	Bound each element below and/or above.
Hampel filter	Robust Hampel despiker, replace samples far from the window median (in MAD units).
Impulse clip	Causal impulse remover, detects spikes on the trend-free first difference.
Rolling mean absolute deviation	Trailing-window mean absolute deviation from the rolling mean.
Rolling median	Trailing-window median.
Rolling median absolute deviation	Rolling median absolute deviation, median(|x - median|), a robust scale estimate.
Rolling sigma-clip	Replace samples outside [mean - lower*std, mean + upper*std] with NaN or the clipped bound.