shortr 1.0.3

Performance

Simulated annealing

• O(base::ceiling(base::log(stop.temp / start.temp) / base::log(cool.fact)) · n) time, O(n^2) space → O(base::ceiling(base::log(stop.temp / start.temp) / base::log(cool.fact)) · k) time, O(n^2) space. Swap evaluation now computes delta updates via unchanged indices (unch.idx), replacing the maintained link vector and matching the brute force update pattern.

shortr 1.0.2

Arguments and value

Renamed arguments

• adj.mat → n.mat. The first argument of interest is n.mat, not necessarily a symmetric adjacency matrix of numeric, but a symmetric matrix of numeric corresponding to the symmetric matrix of associations (e.g., of zero-order polychoric correlation coefficients) computed from the set of items comprised in the original version of the said psychometric instrument.
• method → algorithm. The third argument of interest is algorithm (rather than method), a character matching either “brute.force” or “simulated.annealing” corresponding to the combinatorial search algorithm.

Removed arguments

• absolute now always TRUE.
• max.iter now always base::ceiling(base::log(stop.temp / start.temp) / base::log(cool.fact)).

Renamed value

• optimal.S → solution.character.
• optimal.function.S → solution.numeric.

Robustness and correctness

• base::set.seed() no longer permanently alters the global RNG state. .Random.seed is now saved and restored via base::on.exit().
• Progress bars are now closed via base::on.exit(), ensuring cleanup even on early exit or error.
• The diagonal of the input matrix is now explicitly set to zero before computation, preventing self-associations from inflating the objective.
• NA/NaN values in the input matrix now trigger a warning with a count of affected entries before being replaced with zeros.
• Input validation now checks for Inf values, non-numeric entries, non-square matrices, and matrices smaller than 2 × 2.
• Scalar parameter validation now checks length, type, and NA status consistently across all parameters.
• algorithm now uses base::match.arg() instead of manual %in% checking, supporting partial matching.
• SA-specific parameters (start.temp, cool.fact, stop.temp, n.runs, seed) are now validated only when algorithm = "simulated.annealing".
• Error messages now use call. = FALSE for cleaner console output.
• k = 0 and k = n are now rejected during validation rather than handled as special cases inside the algorithm.
• seed now explicitly accepts NULL to skip setting the RNG state.

Performance

Brute force

• Subsets are now enumerated incrementally with delta updates to the objective function, replacing the previous approach of generating all candidate subsets in memory via utils::combn(). This reduces memory from O(C(n,k) × k) to O(n) and avoids recomputing the full objective at each step.
• When k > n / 2, enumeration is performed over the smaller complement, reducing the number of combinations to evaluate.
• The absolute value matrix is now precomputed once, rather than recomputed inside the objective function at every evaluation.
• Brute force now detects intractable problems (C(n,k) exceeding .Machine$integer.max) and exits with a recommendation to use simulated annealing, rather than attempting to allocate the full combination matrix.

Simulated annealing

• Swap evaluation now runs in O(n) via a maintained link vector, replacing the previous full matrix subsetting at each step.
• The complement set is now maintained incrementally via a logical membership vector, replacing repeated base::setdiff() calls.
• Removed the hash environment that stored all visited subsets as character keys, eliminating unbounded memory growth over long runs.

shortr 1.0.1

• Initial CRAN release.