Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

[Unreleased]

Storage losses per hour where not calculated correctly, as mentioned by @brokenwings01. This might have lead to issues with modeling large losses and long timesteps.
Old implementation: \(c(\text{t}_{i}) \cdot (1-\dot{\text{c}}_\text{rel,loss}(\text{t}_i)) \cdot \Delta \text{t}_{i}\)
Correct implementation: \(c(\text{t}_{i}) \cdot (1-\dot{\text{c}}_\text{rel,loss}(\text{t}_i)) ^{\Delta \text{t}_{i}}\)

Just to mention: Plotly >= 6 may raise errors if "nbformat" is not installed. We pinned plotly to <6, but this may be fixed in the future.

Fixed bug in the _ElementResults.constraints not returning the constraints but rather the variables

Python 3.13 support added
Logger warning if relative_minimum is used without on_off_parameters in Flow
Greatly improved internal testing infrastructure by leveraging linopy's testing framework

Fixed the lower bound of flow_rate when using optional investments without OnOffParameters
Fixed bug that prevented divest effects from working
Added lower bounds of 0 to two unbounded vars (numerical improvement)

BREAKING: Restructured the modeling of the On/Off state of Flows or Components
Variable renaming: ...|consecutive_on_hours → ...|ConsecutiveOn|hours
Variable renaming: ...|consecutive_off_hours → ...|ConsecutiveOff|hours
Constraint renaming: ...|consecutive_on_hours_con1 → ...|ConsecutiveOn|con1
Similar pattern for all consecutive on/off constraints

Replace "|" with "__" in filenames when saving figures (Windows compatibility)
Fixed bug that prevented the load factor from working without InvestmentParameters

BREAKING: Complete migration from Pyomo to Linopy optimization framework
BREAKING: Redesigned data handling to rely on xarray.Dataset throughout the package
BREAKING: Framework renamed from flixOpt to flixopt (import flixopt as fx)
BREAKING: Results handling completely redesigned with new CalculationResults class

Full model serialization support - save and restore unsolved Models
Enhanced model documentation with YAML export containing human-readable mathematical formulations
Extend flixopt models with native linopy language support
Full Model Export/Import capabilities via linopy.Model
Unified solution exploration through Calculation.results attribute
Compression support for result files
to_netcdf/from_netcdf methods for FlowSystem and core components
xarray integration for TimeSeries with improved datatypes support
Google Style Docstrings throughout the codebase