Anomaly Detector using FFT with AMOC and CUSUM Cutoff
Source:R/hanr_fft_amoc_cusum.R
hanr_fft_amoc_cusum.RdThis detector combines FFT-based spectral filtering with an AMOC change-point cutoff applied to the cumulative spectrum. The lower-frequency components are removed, the signal is reconstructed, and the residual is scored for anomalies.
This function extends the HARBINGER framework and returns an object of class hanr_fft_amoc_cusum.
Examples
library(daltoolbox)
# Load anomaly example data
data(examples_anomalies)
# Use a simple example
dataset <- examples_anomalies$simple
head(dataset)
#> serie event
#> 1 1.0000000 FALSE
#> 2 0.9689124 FALSE
#> 3 0.8775826 FALSE
#> 4 0.7316889 FALSE
#> 5 0.5403023 FALSE
#> 6 0.3153224 FALSE
# Configure FFT+CUSUM+AMOC detector
model <- hanr_fft_amoc_cusum()
# Fit the model
model <- fit(model, dataset$serie)
# Run detection
detection <- detect(model, dataset$serie)
# Inspect detected anomalies
print(detection[detection$event, ])
#> idx event type
#> 50 50 TRUE anomaly