ir: Functions to Handle and Preprocess Infrared Spectra

ir version 0.3.0

Bug fixes

• In ir_import_spc(), the returned ir object was not a tbl_df, but a data frame. This is now corrected.
• In unnest.ir(), the ir class was not restored and therefore the result was always unclassed.
• In ir_average(), the returned ir object was still a grouped_df. This is now corrected (by adding the .groups argument for dplyr::summarize() which is internally used by ir_average()).

New functions

• ir_export_prepare() to support exporting ir objects to csv.
• ir_correct_atmosphere() enables correcting for atmospheric artifacts (e.g. H$_2$O and CO$_2$ peaks) following Perez-Guaita et al. (2013) (DOI: 10.1366/13-07159).

Improvements

• Making ir_flatten() faster by improving spectra combining.
• Making ir_bin() faster by improving spectra summarizing per bin. Allowing to specify how wavenumber values should be defined after binning.
• Arithmetic operations now also accept numeric vectors (ir_subtract(), ir_add(), ir_multiply(), ir_divide()).