uv-spectrum

Parse and process UV-Vis absorption spectra. The package wraps common-spectrum with UV-specific variable derivation and ships readers for JCAMP-DX, plain-text two-column data, and Cary Eclipse CSV files.

Installation

$ npm install --save uv-spectrum

Usage

import { fromJcamp } from 'uv-spectrum';

const analysis = fromJcamp(jcamp);

Other readers exposed by the package: fromText and fromCaryEclipseCSV. Core helpers re-exported from common-spectrum (Analysis, AnalysesManager, autoPeakPicking, peakPicking, toJcamp, toMatrix, toText) are also importable from uv-spectrum.

When loading a UV-Vis spectrum, additional variables are derived from the y axis depending on its label:

Absorbance / transmittance input

| Key | Label | Units | Description | | --- | ------------------ | ----- | ---------------------------------------------------------- | | x | Wavelength | nm | Wavelength from the source file | | y | (from source file) | | Original y-axis data | | a | Absorbance | | Absorbance values (computed from transmittance if needed) | | t | Transmittance (%) | | Percent transmittance (computed from absorbance if needed) |

The conversion is automatic: if the y label contains "transmittance", absorbance is computed as -log10(T / factor); if it contains "absorbance", transmittance is computed as 10^(-A) * 100. For transmittance, the presence of % or percent in the label determines whether the input is already scaled to 0-100 or 0-1.

Reflectance input

When the y label contains "reflect", reflectance-derived quantities are added instead:

| Key | Label | Units | Description | | --- | -------------------------------- | --------------- | -------------------------------------------------------- | | x | Wavelength | nm | Wavelength from the source file | | y | (from source file) | | Original reflectance data | | r | Reflectance | | Copy of the original reflectance values | | k | F(R) | | Kubelka-Munk function: (1 - R)^2 / (2 R) | | e | Energy | eV | Photon energy converted from wavelength | | c | (F(R) / 100 * h * v / e)^(1/2) | Arbitrary units | Tauc plot quantity (direct-allowed transition, factor 2) |

API Documentation

License

MIT