CharAnalysis 2.0.2

Patch release addressing the third round of CRAN reviewer feedback, plus a related rendering fix discovered during local testing. No changes to analytical behaviour.

CharAnalysis 2.0.1

Patch release addressing CRAN reviewer feedback on the initial submission. No changes to analytical behaviour.

CharAnalysis 2.0.0

First R implementation of CharAnalysis, a direct translation of CharAnalysis v2.0 (MATLAB). Analytical outputs are validated against four benchmark datasets; user testing is ongoing. The package is in the experimental lifecycle stage: the API may change as user feedback is incorporated.

Please report issues at https://github.com/phiguera/CharAnalysis/issues.

New features relative to MATLAB v2.0

Known differences from MATLAB v2.0

Robust lowess background (smoothing method 2). MATLAB’s Curve Fitting Toolbox smooth(..., 'rlowess') and the R char_lowess() port handle NaN gaps differently inside the bisquare robustness iteration, producing slightly different C_background series for records with missing values. For gap-free records the difference is negligible (< 0.001); for records with NaN gaps the maximum absolute difference across validated datasets is 0.267 (Chickaree Lake). Smoothing method 1 (plain lowess) is unaffected and agrees to within floating-point noise.

GMM peak counts. The Gaussian mixture model EM algorithm accumulates floating-point arithmetic differently in R and MATLAB, causing slightly different threshold values in some local windows. Peak counts differ by 10–20% across validated datasets, with the direction varying by dataset.

Figures 9 and 10. The threshold-sensitivity detail plot (Fig. 9) and multi-site comparison plot (Fig. 10) from the MATLAB interface are not implemented in this R package.

Smoothed FRI column (col 23). The R package computes smoothed fire-return intervals in this column; MATLAB v2.0 stores NaN.

Validation summary

Dataset Site charBkg max|diff| Peaks R Peaks MATLAB
CO Code Lake, AK ~5 × 10-6 39 48
CH10 Chickaree Lake, CO 0.267 59 50
SI17 Silver Lake, CO 0.130 25 31
RA07 Raven Lake, AK < 0.001 15 17

Full validation details are in inst/z_Validation_report_R_vs_MATLAB_V_2.0.md.

Citation

If you use CharAnalysis in published research, please cite:

Higuera, P.E., L.B. Brubaker, P.M. Anderson, F.S. Hu, and T.A. Brown. 2009. Vegetation mediated the impacts of postglacial climate change on fire regimes in the south-central Brooks Range, Alaska. Ecological Monographs 79:201–219. https://doi.org/10.1890/07-2019.1

If you used Version 2.0 specifically, please also cite the software:

Higuera, P.E. 2026. CharAnalysis: Diagnostic and analytical tools for peak analysis in sediment-charcoal records (Version 2.0). Zenodo. https://doi.org/10.5281/zenodo.19304064