pp_direct_standardization — Direct standardization (DS)¶
Group: Signal transforms · C ABI: n4m_domain_adaptation_direct_standardization_*
Description¶
Direct standardization transfer map between paired instruments.
Parameters¶
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API and bindings¶
C ABI (ABI 2): n4m_domain_adaptation_direct_standardization_create · n4m_domain_adaptation_direct_standardization_destroy · n4m_domain_adaptation_direct_standardization_fit · n4m_domain_adaptation_direct_standardization_is_fitted · n4m_domain_adaptation_direct_standardization_transform. Use the linked public header for the exact signature, configuration, and result handles.
Python (verified public re-export):
from n4m.domain_adaptation.standardization import direct_standardization
Source signature: direct_standardization(X_source, X_target, X = None, fit_intercept: bool = True, ridge: float = 0.0).
R: no current source-verified entry point was found for this catalog method.
MATLAB / Octave: no current source-verified entry point was found for this catalog method.
Explanations¶
Bibliographic source¶
Wang et al. (1991), Improvement of multivariate calibration through instrument standardization, Analytical Chemistry 63, 2750–2756, https://doi.org/10.1021/ac00023a016.
Mathematical principle¶
Using paired source and target spectra, DS fits a global affine map \(X_s B+\mathbf{1}b\approx X_t\) by least squares, optionally with ridge regularization. New source spectra are multiplied by the learned transfer matrix.
Appropriate uses¶
Transferring a calibration between instruments or measurement conditions when representative paired standards are available.
Limits and validation¶
It requires paired samples and assumes one global linear relation. With many wavelengths the map can overfit unless regularized; extrapolation beyond transfer standards is unsafe.
Implementation¶
n4m.domain_adaptation.standardization.DirectStandardization wraps n4m_domain_adaptation_direct_standardization_*; fitting is in cpp/src/c_api/c_api_advanced.cpp.
The ABI-2 implementation is the n4m_domain_adaptation_direct_standardization_* lifecycle in libn4m.
Sources and provenance¶
https://doi.org/10.1021/ac00023a016; https://github.com/GBeurier/nirs4all-methods/blob/main/cpp/src/c_api/c_api_advanced.cpp
See also: methods index · interactive dashboard