QSS Solver

The QSS Solver is a modeling and simulation environment for continuous and hybrid systems and it's optimized for large scale model simulation. The solver is implemented as a set of modules coded in plain C language, simulations can be performed using one of the following integration methods:

• QSS methods (the entire family is supported)
• DASSL
• DOPRI
• CVODE
• IDA

Models are described using a subset of the standard Modelica language called μ–Modelica (the language specification can be found here), the compiler extracts all the structural information needed and automatically generates the plain C code that contains an appropiate model definition needed by the QSS Solver engine together with all the configuration files (makefiles, config, etc.).

The QSS Solver has a simple GUI interface that allows the end-user to access all the developed tools in a unified way.

The GUI has the following features:

• It has a text editor, where models in μ-Modelica can be defined.
• It invokes the corresponding tools to compile and run simulations.
• It provides debug information in case of errors during the model generation.
• It invokes GnuPlot to plot the simulation output trajectories.
• It shows statistics about simulations (number of steps, simulation time, etc.).

How to Install

Using QSS Solver GUI

Load a Model

Create a New Model

Import SBML Models

MicroModelica Model Annotations

Solver

• MMO_DebugGraph: .
• MMO_DerDelta: .
• MMO_Description: A textual description of the model.
• MMO_GenerateArch: .
• MMO_MinStep: .
• MMO_NodeSize:
• MMO_Output: .
• MMO_OutputType: .
• MMO_Period: .
• MMO_RandomSeed: .
• MMO_Scheduler: .
• MMO_Solver: .
• MMO_StoreData: .
• MMO_SymDiff: .
• MMO_Weight: .
• MMO_XOutput: .
• MMO_ZCHyst: .

User Defined Matrix Values

• MMO_DH: .
• MMO_Event_Id: .
• MMO_HD: .
• MMO_HH: .
• MMO_HZ: .
• MMO_LHS_DSC: .
• MMO_LHS_ST: .
• MMO_RHS_ST: .
• MMO_SD: .
• MMO_SH: .
• MMO_SZ: .

Hybrid QSS BDF Solver

• MMO_BDF_Max_Step: .
• MMO_BDF_Part: .
• MMO_BDF_PDepth: .

Parallel Solver

• MMO_LPS: .
• MMO_DT_Min: .
• MMO_DT_Synch: .
• MMO_Parallel: .

External Partitioners

• MMO_Imbalance: .
• MMO_MetisSettings: .
• MMO_PartitionMethod: .
• MMO_PatohSettings: .
• MMO_ReorderPartition: .
• MMO_ScotchSettings: .

Classic Integration Methods

• MMO_CVODEMaxOrder: .

Compile and Run Models

Run Models

Debug Generated Model Instances

View Simulation Logs

Plot Simulation Results

Application Settings

Compiler Flags

Environment Variables

Both the GUI and MicroModelica compiler use environment variables for the

Commands

Debugging Options

• Enable All: Enable all the debug flags.
• Dt: Log dt parameter changes in parallel simulations.
• External Events: Log step information for each external event in parallel simulations.
• Initial Values: Log the simulation initialization, including initial state and state derivatives values.
• Memory: Log memory footprint.
• Sinchronize: Output synchronization information in parallel simulations.
• Step Information: Log for each simulation step: ** The step time ** The type and index of the variable that changes
• Variable Changes: Log the model's state variable changes and the number of handler executions for each event defined in the model.
• Waiting Time: Log synchronization information in parallel simulations.
• Generate Weights File: Save all the variables changes information into a binary file, useful for semi-static partitioning of parallel simulations. This option implies Variable Changes.

Additional Compiler Options:

• -e, --external-structure-file Read model incidence matrices from .
• -f, --force Force external package compilation. *-i , --include Include in the library path search.
• -o , --output Sets the output to
• -s, --settings-only Generate only the settings (.ini) file.