NEWS

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circhelp 1.4.1

• Add circ_lin_loess() and circ_circ_loess() to distinguish linear and circular responses to circular predictors.
• Add circ_y to circ_loess(): FALSE (the default) selects the linear-response smoother, while TRUE selects the circular-response smoother. Existing calls retain their linear-response fits.
• The circular-response smoother supports a separate response_space, averages responses across wrap boundaries, and computes uncertainty from local angular residuals. Undefined mean directions return NA.
• Add prediction methods for both explicit smoother classes and support se.fit = FALSE as well as confidence bands, including use through ggplot2::geom_smooth().
• Document the response-type distinction and add regression tests for legacy compatibility, period invariance, wrap boundaries, prediction, and plotting.

circhelp 1.4.0 (2026-10-09)

• density_asymmetry(): the kernel density estimate is now wrapped around the circle (wrap = TRUE), so mass near +/- circ_space/2 is no longer truncated. This is a no-op to ~1e-13 for orientation or colour errors, but it matters for data with a 180-degrees-off reversal mode, such as motion direction.
• density_asymmetry(): the +/- circ_space/2 point is now excluded from the positive and negative sums (exclude_antipode = TRUE), like zero. It is the same angle reached from two sides, and with an odd n it was counted twice.
• density_asymmetry(): a bandwidth narrower than the grid spacing now rescales yvar and the bandwidth together (rescale_narrow = TRUE) so the kernel spans at least one cell. Without it, the rectangle sum aliases: on a narrow error distribution with bw.SJ()-selected bandwidth the returned asymmetry was off by 7.5% of its value at the default n = 181, now 0.4%.
• density_asymmetry(): the two signs are now paired on a rounded abs(x), since seq() is not bitwise symmetric for every n (on n = 1801, 604 of 900 pairs failed to match and dropped out of the sums entirely).
• density_asymmetry_discrete(): the same four fixes, with the same argument names and defaults. Wrapping there is done by evaluating stats::density() over the neighbouring periods and folding the images back, since augmenting the sample with shifted copies would run into density()'s binning range.
• The fixes above default to the corrected behaviour; pass wrap = FALSE, exclude_antipode = FALSE, rescale_narrow = FALSE for pre-1.4.0 results.

circhelp 1.3.1

• Added circ_mean(), circ_sd(), and angle_diff(), generalized versions of the _rad/_180/_360 family that accept an arbitrary period argument (e.g., 180, 360, or anything else).
• Added a period argument to weighted_circ_mean() to compute the weighted circular mean directly on data in an arbitrary circular space, without manually converting to radians first.

circhelp 1.3

• remove_cardinal_biases(): replaced gamlss dependency with a native P-spline + REML/EM implementation. Results are numerically equivalent; runtime is approximately 2× faster.
• Removed gamlss from package imports.

circhelp 1.2

• Added density_asymmetry_discrete().
• Added smoothed_circ_sd().
• Improved density_asymmetry() speed and options.

circhelp 1.1.3

• Added smoothed_circ_sd().
• Improved speed of density_asymmetry() by using matrix multiplication.
• Added "average" as a bandwidth option in density_asymmetry().
• Updated imports (ggplot2, stats) and documentation.

circhelp 1.1.2

• Added density_asymmetry_discrete().
• Added return_full_density option to density_asymmetry().
• Updated vignettes and package documentation/site build.

circhelp 1.1.1

• Added density_asymmetry() to analyze the asymmetry in response probabilities.

circhelp 1.1 (2024-07-04)

• Initial CRAN submission.