ASCEND capabilities - Revision history

Jpye at 11:02, 4 March 2026

2026-03-04T11:02:55Z

← Older revision		Revision as of 11:02, 4 March 2026
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	* Procedural initialisation of models and solver parameters using [[METHOD]]s		* Procedural initialisation of models and solver parameters using [[METHOD]]s
	* [[WHEN]] syntax for [[conditional modelling]] also known as 'variable-structure modelling'.		* [[WHEN]] syntax for [[conditional modelling]] also known as 'variable-structure modelling'.
			* [[DATASET]] allows loading of CSV/TSV tabular data. Also [[Data reader]] which is used for interpolation/time-series datasets (for [[DAE]] problems, say).
	* Differential as well as algebraic equations can be expressed		* Differential as well as algebraic equations can be expressed
	* Constants are declared separately from variables		* Constants are declared separately from variables
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	* Detection of singular and non-square equation systems; user is advised on what modifications would help to make system square.		* Detection of singular and non-square equation systems; user is advised on what modifications would help to make system square.
	* Steady-state [[QRSlv]] solver with block decomposition		* Steady-state [[QRSlv]] non-linear algebraic (NLA) solver with block decomposition.
	* ~~Optimisation solver~~ [[IPOPT]] ~~as well as linking to commercial~~ [[CONOPT]] solver		* Non-linear programming (NLP)/optimisation solvers [[IPOPT]] (open source) and [[CONOPT]] (commercial).
	* ODE and DAE ~~solver~~ for [[dynamic modelling]]: [[IDA]], [[RADAU5]], [[LSODE]]		* Mixed-integer programming solver [[HiGHS]].
			* ODE and DAE solvers for [[dynamic modelling]]: [[IDA]], [[RADAU5]], [[LSODE]]
	* Some preliminary support for dynamic switching models with boundaries, see [[integration of conditional models]].		* Some preliminary support for dynamic switching models with boundaries, see [[integration of conditional models]].
	* Solver parameters can be set from within the model code (see [[SOLVER]] and [[OPTION]] statements)		* Solver parameters can be set from within the model code (see [[SOLVER]] and [[OPTION]] statements). Model language allows solving of whole models or just a sub-model.
	* New solvers can easily be added, implemented as [[external libraries]] that access our Solver API.		* New solvers can easily be added, implemented as [[external libraries]] that access our Solver API.

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	* View [[incidence matrix]] showing block-decomposed structure of steady-state systems		* View [[incidence matrix]] showing block-decomposed structure of steady-state systems
	* Diagnose blocks in the model which have been giving numerical problems		* Diagnose blocks in the model which have been giving numerical problems
			* Observer/study feature: sweep variables and solve each time, to generate tabular/plot outputs from a flowsheet.
	* View [[incidence graph]] (aka dependency graph) for solution process		* View [[incidence graph]] (aka dependency graph) for solution process
	* Plot the time-varying values from the solution of dynamic problems		* Plot the time-varying values from the solution of dynamic problems

Jpye: /* Solver features */

2013-04-03T05:09:32Z

Solver features

← Older revision		Revision as of 05:09, 3 April 2013
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	* Steady-state [[QRSlv]] solver with block decomposition		* Steady-state [[QRSlv]] solver with block decomposition
	* Optimisation solver [[IPOPT]] as well as linking to commercial [[CONOPT]] solver		* Optimisation solver [[IPOPT]] as well as linking to commercial [[CONOPT]] solver
	* ODE and DAE ~~solvers~~: [[IDA]], [[RADAU5]], [[LSODE]]		* ODE and DAE solver for [[dynamic modelling]]: [[IDA]], [[RADAU5]], [[LSODE]]
	* Some preliminary support for dynamic switching models with boundaries, see [[integration of conditional models]].		* Some preliminary support for dynamic switching models with boundaries, see [[integration of conditional models]].
	* Solver parameters can be set from within the model code (see [[SOLVER]] and [[OPTION]] statements)		* Solver parameters can be set from within the model code (see [[SOLVER]] and [[OPTION]] statements)

Jpye at 05:08, 3 April 2013

2013-04-03T05:08:41Z

← Older revision		Revision as of 05:08, 3 April 2013
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	* Interactive exploration of the numerical/convergence behaviour of the model		* Interactive exploration of the numerical/convergence behaviour of the model
	* Capture the state of selected variables for export/plotting via [[Observer]] functionality		* Capture the state of selected variables for export/plotting via [[Observer]] functionality
	* View incidence matrix showing block-decomposed structure of steady-state systems		* View [[incidence matrix]] showing block-decomposed structure of steady-state systems
	* Diagnose blocks in the model which have been giving numerical problems		* Diagnose blocks in the model which have been giving numerical problems
	* View dependency graph for solution process		* View [[incidence graph]] (aka dependency graph) for solution process
	* Plot the time-varying values from the solution of dynamic problems		* Plot the time-varying values from the solution of dynamic problems
	* Alpha-quality [[canvas-based modeller for ASCEND]] allows 'wiring up' of graphical 'blocks' to construct complex flowsheets		* Alpha-quality [[canvas-based modeller for ASCEND]] allows 'wiring up' of graphical 'blocks' to construct complex flowsheets

Jpye: /* Language features */

2013-04-03T02:13:12Z

Language features

← Older revision		Revision as of 02:13, 3 April 2013
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	== Language features ==		== Language features ==

	* Equation-based language, see ''[http://ascend.cheme.cmu.edu/ftp/pdfPapersRptsSlides/processModeling.pdf Equation-based Process Modeling]]'' for an overview.		* Equation-based language, see ''[http://ascend.cheme.cmu.edu/ftp/pdfPapersRptsSlides/processModeling.pdf Equation-based Process Modeling]'' for an overview.
	* Full support for [[units of measurement]]; user never needs to worry about conversion factors.		* Full support for [[units of measurement]]; user never needs to worry about conversion factors.
	* Hierarchical [[MODEL]]s allowing modular system models built from reused components		* Hierarchical [[MODEL]]s allowing modular system models built from reused components

Jpye: /* Language features */

2013-04-03T02:12:45Z

Language features

← Older revision		Revision as of 02:12, 3 April 2013
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	== Language features ==		== Language features ==

	* Equation-based language		* Equation-based language, see ''[http://ascend.cheme.cmu.edu/ftp/pdfPapersRptsSlides/processModeling.pdf Equation-based Process Modeling]]'' for an overview.
	* Full support for [[units of measurement]]; user never needs to worry about conversion factors.		* Full support for [[units of measurement]]; user never needs to worry about conversion factors.
	* Hierarchical [[MODEL]]s allowing modular system models built from reused components		* Hierarchical [[MODEL]]s allowing modular system models built from reused components

Jpye: /* Solver features */

2013-04-03T02:10:54Z

Solver features

← Older revision		Revision as of 02:10, 3 April 2013
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	* Optimisation solver [[IPOPT]] as well as linking to commercial [[CONOPT]] solver		* Optimisation solver [[IPOPT]] as well as linking to commercial [[CONOPT]] solver
	* ODE and DAE solvers: [[IDA]], [[RADAU5]], [[LSODE]]		* ODE and DAE solvers: [[IDA]], [[RADAU5]], [[LSODE]]
	* Some preliminary support for dynamic switching models with boundaries		* Some preliminary support for dynamic switching models with boundaries, see [[integration of conditional models]].
	* Solver parameters can be set from within the model code (see [[SOLVER]] and [[OPTION]] statements)		* Solver parameters can be set from within the model code (see [[SOLVER]] and [[OPTION]] statements)
	* New solvers can easily be added, implemented as [[external libraries]] that access our Solver API.		* New solvers can easily be added, implemented as [[external libraries]] that access our Solver API.

Jpye: /* Thermodynamics and Engineering features */

2013-04-03T02:08:56Z

Thermodynamics and Engineering features

← Older revision		Revision as of 02:08, 3 April 2013
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	* {{src\|models/thermodynamics.a4l}} code for basic-level accuracy of pure species as well as mixtures		* {{src\|models/thermodynamics.a4l}} code for basic-level accuracy of pure species as well as mixtures
	* [[FPROPS]] code for accurate calculation of pure species properties		* [[FPROPS]] code for accurate calculation of pure species properties
			* linkage to [[freesteam]] library for calculation of steam properties by official IAPWS-IF97 correlations.
	* A range of models for [[Energy system modelling with ASCEND\|energy system modelling], including [[Brayton cycle]], [[Rankine cycle]] and several solar thermal energy component models.		* A range of models for [[Energy system modelling with ASCEND\|energy system modelling], including [[Brayton cycle]], [[Rankine cycle]] and several solar thermal energy component models.
	* Models of mixers, separators and reactors for chemical process modelling (eg {{src\|models/flash.a4l}})		* Models of mixers, separators and reactors for chemical process modelling (eg {{src\|models/flash.a4l}})

Jpye: /* Solver features */

2013-04-03T01:53:27Z

Solver features

← Older revision		Revision as of 01:53, 3 April 2013
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	== Solver features ==		== Solver features ==

	* Detection of singular and non-square equation systems		* Detection of singular and non-square equation systems; user is advised on what modifications would help to make system square.
	* Steady-state [[QRSlv]] solver with block decomposition		* Steady-state [[QRSlv]] solver with block decomposition
	* Optimisation solver [[IPOPT]] as well as linking to commercial [[CONOPT]] solver		* Optimisation solver [[IPOPT]] as well as linking to commercial [[CONOPT]] solver

Jpye: /* Language features */

2013-04-03T01:52:19Z

Language features

← Older revision		Revision as of 01:52, 3 April 2013
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	* Equation-based language		* Equation-based language
			* Full support for [[units of measurement]]; user never needs to worry about conversion factors.
	* Hierarchical [[MODEL]]s allowing modular system models built from reused components		* Hierarchical [[MODEL]]s allowing modular system models built from reused components
	* Procedural initialisation of models and solver parameters using [[METHOD]]s		* Procedural initialisation of models and solver parameters using [[METHOD]]s

Jpye at 01:50, 3 April 2013

2013-04-03T01:50:12Z

← Older revision		Revision as of 01:50, 3 April 2013
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	The following is a summary of current ASCEND capabilities. It is intended to be a complete list. If you want a more general/introductory overview, see the [[ASCEND overview]]. The main page for accessing greater detail on these topics is our [[:Category:Documentation\|documentation]] index.		The following is a summary of current ASCEND capabilities. It is intended to be a complete list. If you want a more general/introductory overview, see the [[ASCEND overview]]. The main page for accessing greater detail on these topics is our [[:Category:Documentation\|documentation]] index. This page emphasises the newer PyGTK-based GUI for ASCEND. An overview of the features of the older Tcl/Tk GUI is can be obtained from the [[TclTk screenshots]].

	== Language features ==		== Language features ==