Process flow - decompose
Calculating derivatives (dervatives) is one of the optional methods for spectral data information enhancement (spectraInfoEnhancement). The position of the process in the chain is indicated in the schematic flow chart below.
|____SpectralData
| |____filter
| | |____singlefilter
| | |____multiFilter
| |____dataSetSplit
| | |____spectralInfoEnhancement
| | | |____scatterCorrection
| | | |____standardisation
| | | |____derivatives
Introduction
In many cases the signal derived from derivates carries more information than the spectra itself. In the process flow you can extract the first derivative and either keep or discard the original spectral signal in the subsequent steps. To invoke derivation you have to set apply to true and derive to the n:th derivate (at present only the first derivative is supported) you want to retrieve (derive set 0 equals the original data). If join is set to true, the derivatives will be joined as new covariates, if set to false the derivates will replace the existing covariates. At present the process flow only supports retrieving the first derivative.
"spectraInfoEnhancement": {
"apply": true,
"derivatives": {
"apply": true,
"derive": 1,
"join": false
}
}
Figure 1 illustrates the derivatives retrieved from the original spectral data (left) and the spectral data after L2 normalisation.
