Introduction to developing or migrating models to be compliant to the OpenMI Standard. OpenMI is an open standard which allows dynamic linking of numerical models, such as river models rainfall-runoff models and so on. See also: http://www.lictek.com

1. OpenMI Developers Training
Jan Gregersen
http://www.LicTek.com
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2. Simple River
Runoff Model Simple River
OutputExchangeItem InputExchangeItem
Quantity ID : Runoff
Quantity ID : Inflow
DataOperaiton : Distributed
ElementSet : Polygons ElementSet : Polyline
Y (km) 5 10
Y (km)
10
10 Node:0
Branch:0
Node:1
5
5
Branch:1
Node:2
Branch:2
Node:3
X (km)
X (km)
5 10
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3. How it works
Load components:
Query exchange items:
Add links:
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4. How it works
Prepare:
Run (GetValues):
Finish:
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5. The OpenMI standard
DHI - Water & Environment Jan Gregersen

6. Jan Gregersen 6

7. Migration of models
DHI - Water & Environment Jan Gregersen

8. Now What ???
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9. Org.OpenMI.Utilities
Org.OpenMI.Utilities.Buffer Buffers results from the engine core
SmartBuffer
Mapping of values associated to one array of
times /timespans to values represented on another
array of times/timespans
t t
Org.OpenMI.Utilities.Spatial
Mapping of values associated to
ElementMapper one ElementSet to be represented
on another ElementSet
Org.OpenMI.Utilities.Wrapper
Generic wrapper suited for time
SmartWrapper stepping model engines
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10. LinkableEngine features
• Provides a default implementation of the
ILinkableComponent interface
• Links bookkeeping
• Event handling
• Buffering
• Temporal interpolations, aggregations,
extrapolations
• Spatial interpolations, aggregations,
extrapolations
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11. Wrapper design pattern
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12. IEngine Interface
// -- Execution control methods (Inherited from IRunEngine) --
void Initialize(Hashtable properties);
bool PerformTimeStep();
void Finish();
//-- Time methods (Inherited from IRunEngine) --
ITime GetCurrentTime();
ITime GetInputTime(string QuantityID, string ElementSetID);
ITimeStamp GetEarliestNeededTime();
//-- Data access methods (Inherited from IRunEngine) --
void SetValues(string QuantityID, string ElementSetID, IValueSet values);
IValueSet GetValues(string QuantityID, string ElementSetID);
//-- Component description methods (Inherited from IRunEngine) --
double GetMissingValueDefinition();
string GetComponentID();
string GetComponentDescription();
// -- Model description methods --
string GetModelID();
string GetModelDescription();
double GetTimeHorizon();
// -- Exchange items --
int GetInputExchangeItemCount();
int GetOutputExchangeItemCount();
org.OpenMI.Backbone GetInputExchangeItem(int exchangeItemIndex);
org.OpenMI.Backbone GetOutputExchangeItem(int exchangeItemIndex);
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13. Inside the LinkableEngine
has SmartWrapper has
SmartInputLinkSet SmartOutputLinkSet
UpdateInput() UpdateBuffer()
1
GetValues()
access
has Link access 1
Link has
* *
SmartInputLink SmartOutputLink
UpdateInput() has UpdateBuffer()
GetValues()
has
SmartBuffer ElementMapper
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14. GetValues()
Model B Model A
GetValues(time, LinkID)
GetValues(time, LinkID)
1. Update with input from linked models
2. Perform time step and fill internal buffers
While (CurrentTime < time & State is “Not Busy”)
3. Map values in time and space
Return values
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15. GetValues()
Model B Model A
GetValues(time, LinkID)
GetValues(time, LinkID)
1. Update with input from linked models
2. Perform time step and fill internal buffers
While (CurrentTime < time & State is “Not Busy”)
3. Map values in time and space
Return values
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16. GetValues()
Engine Smart A Smart A Smart A Smart
A Smart
Model B Model A AIP Output Output Element InputLink Input
Buffer
Access LInkSet LInk Mapper Set Link
GetValues(tl LinkID)
GetCurrentTime()
IsBusy = true UpdateInput(ct)
UpdateInput(ct)
GetValues(ct,LinkID)
SetValues(Quantity,LocationID,Values)
For each Input Link
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17. GetValues()
Model B Model A
GetValues(time, LinkID)
GetValues(time, LinkID)
1. Update with input from linked models
2. Perform time step and fill internal buffers
While (CurrentTime < time & State is “Not Busy”)
3. Map values in time and space
Return values
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18. GetValues()
Engine Smart A Smart A Smart A Smart
A Smart
Model B Model A AIP Output Output Element InputLink Input
Buffer
Access LInkSet LInk Mapper Set Link
PerformTimeStep()
UpdateBuffers()
UpdateBuffer()
Getvalues(Quantity,LocationIDs)
Addvalues(time, valueSet)
For each output link
IsBusy = false
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19. GetValues()
Model B Model A
GetValues(time, LinkID)
GetValues(time, LinkID)
1. Update with input from linked models
2. Perform time step and fill internal buffers
While (CurrentTime < time & State is “Not Busy”)
3. Map values in time and space
Return values
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20. GetValues()
Engine Smart A Smart A Smart A Smart
A Smart
Model B Model A AIP Output Output Element InputLink Input
Buffer
Access LInkSet LInk Mapper Set Link
GetValues(time, LinkID)
GetValues(time)
GetValues(time)
MapValues(inpuValues)
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21. IEngine Interface
// -- Execution control methods (Inherited from IRunEngine) --
void Initialize(Hashtable properties);
bool PerformTimeStep();
void Finish();
//-- Time methods (Inherited from IRunEngine) --
ITime GetCurrentTime();
ITime GetInputTime(string QuantityID, string ElementSetID);
ITimeStamp GetEarliestNeededTime();
//-- Data access methods (Inherited from IRunEngine) --
void SetValues(string QuantityID, string ElementSetID, IValueSet values);
IValueSet GetValues(string QuantityID, string ElementSetID);
//-- Component description methods (Inherited from IRunEngine) --
double GetMissingValueDefinition();
string GetComponentID();
string GetComponentDescription();
// -- Model description methods --
string GetModelID();
string GetModelDescription();
double GetTimeHorizon();
// -- Exchange items --
int GetInputExchangeItemCount();
int GetOutputExchangeItemCount();
org.OpenMI.Backbone GetInputExchangeItem(int exchangeItemIndex);
org.OpenMI.Backbone GetOutputExchangeItem(int exchangeItemIndex);
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22. Wrapper design pattern
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23. Migration steps
• Change your engine to a dll
• Implement Initialize, PerformTimeStep
and Finish
• Create the EngineDllWrapper class
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24. Wrapper design pattern
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25. Migration steps
• Create your MyEnigneWrapper
• Implement Initialize and Finish
• Implement remaining Ienigne methods
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26. Jan Gregersen 26

27. The ElementMapper
Ground water River Model
Model
GetValues(time, link)
Calculate
Return values
Has Link Has
ElementSet
Quantity
“GW Recharge”
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28. Spatial mapping
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29. ElementMapper
Org.OpenMI.Utilties.Spatial
ElementMapper
Initialise(string methodDescription, IElementSet fromElements, IElementSet toElements)
IValueSet MapValues(IValueSet inputValues)
r1 m 11 m 12 m 13 . m1n x1
r2 m 21 m 22 m 23 . m2n x2
r3 m 31 m 32 m 33 . m 3n x3
. . . . . . .
rm m m1 mm2 mm3 . m mn xn
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30. Element Mapping
RE1
RE1 1 1/ 3 0
GE1 GE2
0 2/3 1/ 2
RE3 A
0 0 0
GE3 GE4 0 0 1/ 2
I L A
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31. Element
• ID Based “Node127”
• Point (x1,y1)
• Line (x1,y1) (x2,y2)
• Polyline (x1,y1) (x2,y2) (x3,y3) (x4,y4)
(x1,y1) (x5,y5)
• Polygon (x4,y4)
(x2,y2)
(x3,y3)

32. ElementSet example
H
Q H
H
Q Q
H
Q H H
Q Q
H
H Q
Q H
Q
H
Q
H
Q
H

33. Quantity
• ID ( “Runoff” )
• Description ( “Rainfall runoff” )
• Dimension ( e.g. L3 T-1 )
– GetPower ( <dimensionBase> )
• Unit:
– ID ( “CFS” )
– Descr ( “Cubic feet per second “ )
– ConversionFactorToSI ( 0,0283168439 )
– OffsetToSI ( 0 )

34. ExchangeItem
• InputExchangeItem
– Quantity
– ElementSet
• OutputExchangeItem
– Quantity
– ElementSet
– [ DataOperations
• ID
• Arguments ]

35. Unidirectional link
« t ra e
inef c » « t ra e
inef c »
R eMd l :
iv r o e R md l :
R oe
Min r ga
a P rm
o I ina le o p n n
L k b Cmo e t I ina le o p n n
L k b Cmo e t
Gt a e(im=1 linI = r g r in)
eV lu st et , k Tig eL k
D
[ ]
1
[ ]
2 Gt a e(im= M e+ d, linI = R R e)
eV lu st eR tim _ t k R t iv r
D o
P rom imS p
ef r T e te
[ ]
3
r t r V lu S t Rn f
eun a e e: u of { h R t e< M e+ d}
wile R im R tim _ t
P rom imS p
ef r T e te
{ h R t e< 1
wile M im t }
r t r V lu S t R eF w
eun a e e: iv r lo

36. Bidirectional links
«interface» «interface»
Ri verModel : GroundWaterModel :
MainProgram ILinkableComponent ILinkableComponent
GetValues(t2,TriggerLink)
[1]
GetValues(time=t1, linkID=QtoRiver)
[2]
GetValues(time=t2, linkID=HtoGW)
[3]
Extrapolate (t2)
[4]
return extrapolated ValueSet: HtoGW (t2)
PerformT imeStep (t2)
[5]
return interpolated ValueSet QtoRiver (t1)
PerformTimeStep (t1)
[6]
GetValues(time=t2, linkID=QtoRiver)
[7]
return ValueSet QtoRiver (t2)
PerformT imeStep (t2)
return ValueSet Hriver (t2)
RiverModel uses time step t1, GroundwaterModel uses time step t2

37. Ite ra ti o n C o n tro l l e r « i n te rfa c e » « i n te rfa c e »
: R i v e rM o d e l : G ro u n d W a te rM o d e l :
IL i n ka b l e C o m p o n e n t IL i n ka b l e C o m p o n e n t IL i n ka b l e C o m p o n e n t
M a i n P ro g ra m
G e tV a l u e s(ti m e = t2 , l i n kID = H _ S W )
K e e p C u rre n tS ta te
[1 ] R i v e rS ta te _ t_ b e g i n
K e e p C u rre n tS ta te
G W S ta te _ t_ b e g i n
In i ti a l G u e ss(Q to G W )
[2 ]
R e sto re S ta te (R i v e rS ta te _ t_ b e g i n )
[3 ]
R e sto re S ta te (G W S ta te _ t_ b e g i n )
[4 ]
G e tV a l u e s(ti m e = t2 , l i n kID = H _ G W )
G e tV a l u e s(ti m e = t2 , l i n kID = Q to G W )
Q to G W _ g u e ss
H_ G W
[5 ] G e tV a l u e s(ti m e = t2 , l i n kID = H _ S W )
G e tV a l u e s(ti m e = t2 , l i n kID = Q to G W )
Q to G W _ g u e ss
H_SW
E v a l u a te
[6 ]
N e w G u e ss(Q to G W )
{u n ti l l Q to G W i s sta b i l i z e d }
re su l t: H _ S W
[7 ]

38. « i n te rfa ce » « i n te rfa ce »
R i ve rM o d e l : RR m o d e l :
M a i n P ro g ra m IL i n ka b l e C o m p o n e n t IL i n ka b l e C o m p o n e n t
Use r :
IL i ste n e r
S ta rt
G e tV a l u e s(ti m e = t1 ,T ri g g e rL i n kID )
[1 ]
O n E ve n t(S o u rce A fte rG e tV a l u e sC a l l )
re tu rn co m p u ta ti o n th re a d
G e tV a l u e s(ti m e = t1 ,l i n kID= Q to R i ve r)
[2 ]
O n E ve n t(S o u rce A fte rG e tV a l u e sC a l l )
re tu rn co m p u ta ti o n th re a d
P e rfo rm T i m e S te p ((_ d t))
[3 ] O n E ve n t(D a ta Ch a n g e d )
re tu rn co m p u ta ti o n th re a d
O n E ve n t(S o u rce B e fo re G e tV a l u e sR e tu rn ) {u n ti l RR ti m e = t1 }
P a u se
[4 ]
R e su m e
[5 ] re tu rn co m p u ta ti o n th re a d
re tu rn V a l u e S e t(Q to R i ve r, t1 )
O n E ve n t(T a rg e tA fte rG e tV a l u e sR e tu rn )
[6 ] re tu rn co m p u ta ti o n th re a d
P e rfo rm T i m e S te p (R M _ d t)
O n E ve n t(Da ta C h a n g e d )
[7 ]
O n E ve n t(S o u rce B e fo re G e tV a l u e sR e tu rn )
re tu rn co m p u ta ti o n th e a d
[8 ] re tu rn V a l u e S e t(t1 )

39. Persistency
• OMI File
– For identifying a linkable component
• Composition
– In org.OpenMI.Utilities.Configuration
– Holds administration of links and linkable
components
– Can be run
– Can be written and read to / from xml

40. Exercise 9:
Unit Conversion
Step 1
Open the DataCombinator
Step 2
Adjust the code of GetValues so that it delivers data in the right
unit
Step 3
Adjust the test program to ask for a quantity which has a
conversion factor not equal to one
Step 4
Identify a value as missing value (e.g. -999) and adjust the
input. Make sure this value is processed correctly.
Step 5
Test the program using NUnit