@hackage / dtmc

Changelog

0.2.0.0

First Hackage release.

• Added validated dense and sparse probability distributions.
• Added type-safe finite transition matrices and locally finite transition kernels, with representation-independent finite-horizon evolution and simulation.
• Added finite-time joint and conditional probabilities.
• Added exact-time, bounded, eventual, competing, and expected hitting and return quantities.
• Added finite- and infinite-horizon visit-count analysis, including the occupation matrix.
• Added communicating-class, recurrence, transience, periodicity, and cyclic class analysis.
• Added canonical decomposition, fundamental matrices, and absorption probabilities and expectations.
• Added extremal stationary distributions for every recurrent class, ordinary limiting matrices, and cyclic subsequential limits.
• Added state-labelled and list-based construction and inspection. No hmatrix type appears in the public API.
• Changed the internal dense storage of DistributionVector and TransitionMatrix from statically sized values to ordinary hmatrix vectors and matrices. The public types remain state-indexed and abstract, and their smart constructors continue to validate dimensions against the finite state cardinality.
• Added Dtmc.Distribution.Map.mapStates for transforming sparse distributions, combining the weights of states that share a target.
• Added Dtmc.Transition.Matrix.fromRows, which builds a matrix from a grid of weights and reports shape mismatches as typed errors.
• Made GTH stationary-distribution normalisation robust when finite weights have a sum that overflows Double.
• Reduced dense transition-row lookup from quadratic to linear time and space.
• Made Dtmc.Distribution.Vector.fromList positional: it now takes one weight per state in canonical state order, so it is the exact inverse of toList, and reports a length mismatch through the new DistributionVectorError. Labelled construction, where duplicates combine and missing states default to zero, remains Dtmc.Distribution.Map.fromList.
• Supports GHC 9.6 through 9.14.
• Narrowed Dtmc.Analysis.Classification to the queries themselves. The Classification report and classify are no longer exported, and with them the Of suffixes that existed only to keep record fields from colliding with the standalone functions. absorbingStates, chainPeriod and ergodic are now functions on a matrix, and communicatingClasses returns [CommClass state], carrying each class's period and closedness rather than its members alone.