NEWS.md
In bbuchsbaum/fmrireg: R package for the anlysis of fmri data

fmrireg 0.X.Y (Development)

Design Matrix Column Naming: The naming scheme for columns in design matrices generated by event_model() has been completely revised for consistency and clarity.
- All column names now strictly follow the format: term_tag + _ + condition_tag + [_b## basis suffix].
- term_tag: Automatically generated from variable names (e.g., var1_var2) or user-provided id= in hrf(), sanitized (dots become underscores), and made unique with # suffix if needed (e.g., cond, cond#1).
- condition_tag: Represents factor levels (e.g., Factor.Level), continuous basis columns (e.g., poly_RT_01, z_RT), or interactions joined by _ (e.g., Factor.Level_poly_RT_01).
- _b##: Optional suffix added only when the HRF has multiple basis functions (e.g., _b01, _b02).
- The previous style argument ("compact", "qualified", "uid") in design_matrix() is removed. Only the single canonical format is produced.
- Scripts or analyses that relied on matching previous column name formats (e.g., using Var[Level], Var:Level, :basis[]) will need to be updated to use the new term_tag_Condition.Tag_b## format.

Regressor System Refactoring:
- Introduced a new internal S3 class Reg for representing regressors.
- The main regressor() function now uses Reg internally but maintains backward compatibility (returns class c("regressor", "Reg", "list")).
- Deprecated single_trial_regressor() and null_regressor() in favour of using regressor() directly.
- Unified regressor evaluation under the evaluate.Reg S3 method, supporting different calculation methods ("fft", "conv", "loop", "Rconv").
- Evaluation methods now consistently use the refactored evaluate.HRF for HRF sampling.
- Refactored C++ evaluation code into a single wrapper (evaluate_regressor_cpp).
- Removed redundant internal helper functions (fastevalreg, fastevalreg2, conform_len, dots).
- Implemented autoplot.Reg (ggplot2) and print.Reg (cli) methods, deprecating older plot.regressor and print.regressor.
- Improved input validation and recycling for regressor() arguments using vctrs.
- Added optional sparse matrix output to evaluate.Reg.
- Added memoization for HRF sampling within evaluation.