v1.5.1

Release v1.5.1 (branch release/1.5)

Fixes

• Guard the confined-pass/trap counter increments with !$omp atomic update rather than wrapping the whole branch in a critical region so each counter is updated safely without extra contention.

Full Changelog

v1.5.0...v1.5.1

v1.4.2

Release v1.4.2 (branch release/1.4)

Fixes

• Backport the confined-pass/trap atomic updates so release/1.4 benefits from the same thread-safe counter increments.

Full Changelog

v1.4.1...v1.4.2

v1.5.0

Release v1.5.0 with chartmap reference coordinates, refcoords magfie integration, and deeper verification

Tagged commit date: 2025-12-19
Branch: release/1.5

Major Features

Reference Coordinate System Expansion

• Chartmap reference coordinate support with file detection and validation
• Unified VMEC field coordinate conventions with refcoords
• New coordinate scaling abstraction used by Meiss/Albert modes

Field & Orbit Integration

• magfie_refcoords implementation enabling RK45 integration on any field
• splined_field_t analytic spline derivatives (evaluate_with_der)
• TEST field can run standalone without VMEC files

Verification & Test Coverage

• New unit and integration tests for chartmap pipeline, refcoords, Jacobian conventions,
  hcurl/hctrvr derivations, and NCSX map2disc equivalence
• Added deterministic floating-point mode for reproducible tests

Documentation

• Field/coordinate module docstrings and API cleanup notes
• CHANGELOG updates for recent physics/behavioral changes

Full Changelog

v1.4.1...v1.5.0

v1.4.1

Bug Fixes

• fix: startmode=5 axis singularity - Added s_min=0.01 to prevent numerical issues when sampling particles near the magnetic axis (#204)
• fix: can_to_vmec coordinate conversion in classifier - Enabled coordinate conversion that was previously disabled, fixing classification output

Full Changelog

v1.4.0...v1.4.1

v1.4.0 - Meiss-Hazeltine Coordinates and Performance

Release v1.4.0 with Meiss-Hazeltine canonical coordinates and batch spline optimization

Tagged commit date: 2024-09-05
Branch: release/1.4

Major Features

Canonical Coordinates

• Meiss-Hazeltine coordinates for tokamak perturbations
• Albert canonical coordinates for alternative formulation
• Complete field evaluation system for new coordinate types

Performance Optimization

• Batch spline optimization system
• 2.86x performance improvement in field evaluations
• Efficient batch processing across all field types

Code Quality

• Comprehensive unit test coverage
• Timing diagnostics for execution profiling
• GVEC field integration for advanced applications
• Extensive refactoring and modernization

Configuration Compatibility

Fully backward compatible with v1.3 - existing simple.in files work without modification.

Documentation

• Coordinate systems overview in DOC/coordinates-and-fields.md
• Batch spline implementation details in BATCH_SPLINES_IMPLEMENTATION.md
• Design documentation in DESIGN.md

v1.3.1 - Critical Physics Fix (Recommended)

Release v1.3.1 with critical VMEC flux sign fix

Tagged commit date: 2024-09-04 (cherry-picked)
Branch: release/1.3

Critical Fix

VMEC toroidal flux sign correction (cherry-pick of 5de27cd from main)

• Changes phi = phi/(2*pi) to phi = -phi/(2*pi) in SRC/vmecinm_m.f90
• Ensures correct physics results for VMEC equilibria
• All users on v1.2 or v1.3.0 MUST upgrade to this release

v1.3.0 - Release Branch (March 2025)

Release v1.3.0 from March 31, 2025

Tagged commit date: 2025-03-31
Branch: release/1.3

Changes since v1.2 (7 commits)

New Features

• Deterministic flag for reproducible simulations (controlled random seed)
• Config filename can now be specified via command line argument
• Makefile added for simplified building
• Single fieldline test case added

Bug Fixes

• Initialize end position arrays to zeros
• Removed bmod_ref rescaling (breaking physics change marked as Y in CHANGELOG)

Code Cleanup

• Removed 1349 lines of obsolete draft canonical coordinate code

Important - Missing Critical Fix

This release is missing the VMEC toroidal flux sign fix from Sept 2024.

Users should upgrade to v1.3.1 immediately for correct physics results.

v1.2 - Stable Release (June 2022)

Release v1.2 from June 29, 2022

Tagged commit date: 2022-06-29

Major Changes (127 commits from v1.1.1)

New Features

• Boozer coordinate system support
• Collisions implementation (alpha particles with D-T plasma)
• MPI parallelization support
• Python interface via f90wrap (pysimple)
• ANTS file format support for particle initialization
• Namelist format for configuration files (simple.in)
• VMEC axis healing improvements
• OpenMP for orbit classification
• Record particle end positions

Build System

• CMake improvements for BLAS/LAPACK detection
• Support for older NumPy versions
• Docker container support
• GitHub Actions CI/CD

Documentation

• Added examples for Python interface
• Test scripts for validation

Note: This release is missing the critical VMEC toroidal flux sign fix from Sept 2024. Users should upgrade to v1.3.1 or later.

See CHANGELOG.md for full history.

v1.1.1 - Minpack Integration (Feb 2020)

Release v1.1.1 from February 17, 2020

Tagged commit date: 2020-02-17

Changes (3 commits from v1.1)

New Feature

• Minpack library added with LGPL license

Improvements

• Machine-readable LICENSE file
• Code cleanup

v1.1 - Lambda Evaluation Fix (Feb 2020)

Release v1.1 from February 13, 2020

Tagged commit date: 2020-02-13

Changes (9 commits from v1.0)

Critical Fix

• Lambda now evaluated on half mesh, improves B-field interpolation (marked as Y in CHANGELOG)

Improvements

• Thread safety fixes for OpenMP
• Allocations moved to OpenMP critical sections
• Increased Newton iterations to 32
• Classification in xy removed

This is a breaking change for physics output compared to v1.0.