interval_generator — Fixed and overlapping interval expansion¶
Group: Signal transforms · C ABI: n4m_feature_selection_interval_generator_*
Description¶
Generate fixed or overlapping wavelength intervals.
Parameters¶
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API and bindings¶
C ABI (ABI 2): n4m_feature_selection_interval_generator_create · n4m_feature_selection_interval_generator_destroy · n4m_feature_selection_interval_generator_fit · n4m_feature_selection_interval_generator_is_fitted · n4m_feature_selection_interval_generator_output_cols · n4m_feature_selection_interval_generator_transform · n4m_feature_selection_interval_select. Use the linked public header for the exact signature, configuration, and result handles.
Python (verified public re-export):
from n4m.feature_selection.interval import IntervalGenerator
Source signature: IntervalGenerator(interval_size: int = 32, step: int | None = None).
R (source-verified): interval_select(X, Y, n_components, interval_width = 10L, step = 1L).
The source signature has additional required inputs, so no example call is fabricated.
MATLAB / Octave (source-verified): interval_select(X, Y, n_components, interval_width, step).
The source signature has additional required inputs, so no example call is fabricated.
Explanations¶
Bibliographic source¶
No canonical paper: this is a deterministic interval-construction and column-copy operation; interval_fit is its normative definition.
Mathematical principle¶
Fit creates half-open bands of width interval_size starting every step columns (step=interval_size by default), truncating the last band at the feature count. Transform concatenates every band, so overlapping columns are deliberately repeated.
Appropriate uses¶
Building interval blocks for downstream interval selection or block-wise models, with optional overlap.
Limits and validation¶
It does not score or select intervals. Overlap increases output dimension and repeats features, while position indices assume an already aligned common wavelength grid.
Implementation¶
n4m.feature_selection.interval.IntervalGenerator and interval_generator use n4m_feature_selection_interval_generator_*; construction/copying are in cpp/src/c_api/c_api_advanced.cpp.
The ABI-2 implementation is the n4m_feature_selection_interval_generator_* lifecycle in libn4m.
Sources and provenance¶
https://github.com/GBeurier/nirs4all-methods/blob/main/cpp/src/c_api/c_api_advanced.cpp#L1225-L1303
See also: methods index · interactive dashboard