OpenMI

1. Delft Software Days, OpenMI Symposium, October 31st 2014
OpenMI and other model coupling standards / frameworks
Bert Jagers Stef Hummel Deltares

2. Overview
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Aspects of Modelling Frameworks
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OpenMI
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Overview
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OpenMI 2.0 versus OpenMI 1.4
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Other frameworks
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Various initiatives
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Comparison
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Conclusions
2 Delft Software Days, OpenMI Symposium, October 31st 2014

3. Aspects of Modelling Standards / Frameworks
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Interface based / file based
•
Specification (paper / software)
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Implementation environment (c# / java / fortran / …)
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Meta data for exchanged data?
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User interface?
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Run time framework?
3 Delft Software Days, OpenMI Symposium, October 31st 2014

4. OpenMI
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Interface based (ILinkableComponent)
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No framework required; GUI and runner available
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Data exchange:
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Configuration time: Meta data (‘What’ / ‘Where’)
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Run time, pull driven: Get values per time step (‘When’)
string ID string Description string DetailedDescription ITimeStamp EarliestNeededTime
<<Interface>> ILinkableComponent
void Create(IArgument[] properties) void Initialize() IInputExchangeItem[] GetInputExchangeItems() IOutputExchangeItem[] GetOutputExchangeItems() void AddLink(ILink link) void RemoveLink(string linkID) void PrepareForComputation() IValueSet GetValues(ITime time, string linkID) void Finalize() void Dispose()
What: Quantity Where: ElementSet (Spatial definition)
When: GetValues(time) (time stamp or time span)
4 Delft Software Days, OpenMI Symposium, October 31st 2014

5. What: Quantity
ID ( “Runoff” )
Description ( “Rainfall runoff” )
Dimension ( e.g. L3 T-1 )
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GetPower ( <dimensionBase> ) Unit:
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ID ( “CFS” )
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Descr ( “Cubic feet per second “ )
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ConversionFactorToSI ( 0,0283168439 )
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OffsetToSI ( 0 )
5 Delft Software Days, OpenMI Symposium, October 31st 2014

6. R1
R2
R3
R4
S4
S1
S2
S3
S5
y
2000 m
10000 m
4000 m
6000 m
5000 m
ISIS River
MOUSE Sewer
SOBEK RR Catchments
S6
Ground- Water
Rainfall, IsoHyet 2
Rainfall, IsoHyet 1
x
Where: ElementSets
6 Delft Software Days, OpenMI Symposium, October 31st 2014

7. R1
R2
R3
R4
S4
S1
S2
S3
S5
y
2000 m
10000 m
4000 m
6000 m
5000 m
River
Sewer
Rainfall Runoff Catchments
S6
Ground- Water
Rainfall, IsoHyet 2
Rainfall, IsoHyet 1
x
Where: ElementSets
7 Delft Software Days, OpenMI Symposium, October 31st 2014

8. Linking: What / Where
GUI OpenMI 1.4 (OATC)
8 Delft Software Days, OpenMI Symposium, October 31st 2014

9. Linking: What / Where
FluidEarth GUI OpenMI 2.0
9 Delft Software Days, OpenMI Symposium, October 31st 2014

10. OpenMI 2.0
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SetValues added
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‘Quality’ added (catagorized data)
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More efficient linking
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Mapping no longer in the link, but by means of (a chain of) adapters
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GetValues(time) on output items and on adapters instead of on the linkable component
Component 1
Component 3
Component 2
June 2014: OpenMI 2.0 OGC standard!
10 Delft Software Days, OpenMI Symposium, October 31st 2014

11. 3D flow model with data - at XYZ vertices - at certain timesteps
Link
1.4
2.0
Point1.H
Point2.H
Outflow
Inflow
Point1.H
Point2.H
Grid.H
Input- item
Output- item
Linkable Compo- nent
Legend:
Grid.H
Adapted- Output
polygon to point
t
t
t
t
Provider/Consumer
From 1.4 to 2.0: More efficient linkage
11 Delft Software Days, OpenMI Symposium, October 31st 2014

12. 1.4
2.0
lateral discharge
friction
lateral discharge
friction
Set the values into the input item, according to its location specification and/or its time specification
friction.Values = …
lateralDischarge.Values = …
Tools that (repeatedly) analyse certain "what if" scenario‘s:
Calibration: What if the bottom friction is adjusted, will the model perform better?
Decision support tools: What if somewhere upstream more water is extracted, will there be problems downstream?
From 1.4 to 2.0: Optimizers, Calibration tools
12 Delft Software Days, OpenMI Symposium, October 31st 2014

13. OpenMI Software Development Kits (SDK’s)
OpenMI 1.4:
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c# (OATC, OpenMI Association Techinical Committee)
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java (OATC, Alterra)
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proprietary SDK’s OpenMI 2.0:
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c# (OATC)
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Fluid Earth
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proprietary SDK’s
13 Delft Software Days, OpenMI Symposium, October 31st 2014

14. Wrapping computational (Fortran) cores
Computational core
Initialize
PerformTimeStep
Finalize
Initialize
PerformTimeStep
Finalize
GetValues(…)
Set<varType>(varId)
Get<varType>(varId)
Get<varType>(varId)
GetValues(…)
GetValues(…)
Standardized interface (ILinkableComponent)
Non-standardized interface (in OpenMI)
Non-standardized interface (in OpenMI)
However, obvious level for standardization. E.g.: CSDMS’ BMI (Basic Model Interface)
14 Delft Software Days, OpenMI Symposium, October 31st 2014

15. Other frameworks
and many more … FRAMES CHyMP DeltaShell LIQUID ModCom Danubia …
OASIS
OMS
HLA
Delft-FEWS
HydroPlatform
15 Delft Software Days, OpenMI Symposium, October 31st 2014

16. Other frameworks
Topics
HLA
OMS
All technologies listed define component as a software package or a module that encapsulates a set of related functions.
Science components generally represent a coherent subset of the physical processes for the whole (or part of the) simulation domain.
However …
OASIS
16 Delft Software Days, OpenMI Symposium, October 31st 2014

17. Comparison
Topics
Framework
Interfaces
Implementation provided
… the technologies differ with respect to the degree to which they impose an overall architecture/provide a framework, restrict component interfaces, and provide an implementation for the framework and interface routines.
R
R
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18. Comparison
Topics
Framework
Interfaces
Implementation provided
R
R
Exchanged var.s defined
Although most technologies prescribe a component interface, it turns out that only half of them demand a description of the variables exchanged. If they do, it’s generally in some kind of parameter-location-time way.
18 Delft Software Days, OpenMI Symposium, October 31st 2014

19. Comparison
Topics
Framework
Interfaces
Implementation provided
R
R
Exchanged var.s defined
Code invasiveness
--
+
++
-
A basic comparison of code invasiveness was carried out for four of these coupling technologies by Lloyd et al (2009). A (scalar) water balance model was used for this evaluation. The OMS framework came out as least invasive, mainly due to the use of Java annotations to identify input and output arguments.
19 Delft Software Days, OpenMI Symposium, October 31st 2014

20. Comparison
Topics
Framework
Interfaces
Implementation provided
R
R
Exchanged var.s defined
Code invasiveness
--
+
++
-
Plug & play (GUI)
About half of the groups allow components to be brought together at run time (contrary to compile/link time). In some cases thre’s a GUI that supports this plug & play character.
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21. Comparison
Topics
Support for HPC
C/Fortran support
W
W
W
W
Java support
.NET support
Roughly half of the technologies have been developed with HPC applications in mind.
All technologies have solutions to adopt components written in C/C++ and Fortran.
Java support is less common, but more frequent than .NET support.
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22. Conclusions
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There are a lot of different technologies that one can use to connect components in a modular way.
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The various technologies have been developed from different backgrounds, but are converging towards common concepts.
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Due to differences in application requirements, various technologies will continue to co-exist.
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However, co-operation between coupling technology developers is strongly recommended to improve reusability of components across these frameworks.
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OpenMI is highly fit for hydrological applications:
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Establish the correct links by using meta data (large variability in model concepts, quantities, and units)
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Very flexible data conversions by means of the adapters
22 Delft Software Days, OpenMI Symposium, October 31st 2014