Running: ./testmodel.py --libraries=/home/hudson/saved_omc/libraries/.openmodelica/libraries/ --ompython_omhome=/usr BuildingSystems_BuildingSystems.Climate.Examples.TiltedRadiation.conf.json loadFile("/home/hudson/saved_omc/libraries/.openmodelica/libraries/ModelicaServices 4.0.0+maint.om/package.mo", uses=false) loadFile("/home/hudson/saved_omc/libraries/.openmodelica/libraries/Complex 4.0.0+maint.om/package.mo", uses=false) loadFile("/home/hudson/saved_omc/libraries/.openmodelica/libraries/Modelica 4.0.0+maint.om/package.mo", uses=false) loadFile("/home/hudson/saved_omc/libraries/.openmodelica/libraries/NcDataReader2 2.5.1-master/package.mo", uses=false) loadFile("/home/hudson/saved_omc/libraries/.openmodelica/libraries/BuildingSystems 2.0.0-master/package.mo", uses=false) Using package BuildingSystems with version 2.0.0-beta (/home/hudson/saved_omc/libraries/.openmodelica/libraries/BuildingSystems 2.0.0-master/package.mo) Using package NcDataReader2 with version 2.5.1 (/home/hudson/saved_omc/libraries/.openmodelica/libraries/NcDataReader2 2.5.1-master/package.mo) Using package Modelica with version 4.0.0 (/home/hudson/saved_omc/libraries/.openmodelica/libraries/Modelica 4.0.0+maint.om/package.mo) Using package Complex with version 4.0.0 (/home/hudson/saved_omc/libraries/.openmodelica/libraries/Complex 4.0.0+maint.om/package.mo) Using package ModelicaServices with version 4.0.0 (/home/hudson/saved_omc/libraries/.openmodelica/libraries/ModelicaServices 4.0.0+maint.om/package.mo) Running command: "" <> buildModelFMU(BuildingSystems.Climate.Examples.TiltedRadiation,fileNamePrefix="BuildingSystems_BuildingSystems_Climate_Examples_TiltedRadiation",fmuType="me",version="2.0",platforms={"static"}) "" <> buildModelFMU(BuildingSystems.Climate.Examples.TiltedRadiation,fileNamePrefix="BuildingSystems_BuildingSystems_Climate_Examples_TiltedRadiation",fmuType="me",version="2.0",platforms={"static"}) Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/ModelicaServices 4.0.0+maint.om/package.mo): time 0.001374/0.001374, allocations: 99.78 kB / 15.05 MB, free: 1.105 MB / 14.72 MB Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Complex 4.0.0+maint.om/package.mo): time 0.001686/0.001686, allocations: 177.3 kB / 15.95 MB, free: 216 kB / 14.72 MB Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Modelica 4.0.0+maint.om/package.mo): time 1.72/1.72, allocations: 223.2 MB / 239.9 MB, free: 5.445 MB / 190.1 MB Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/NcDataReader2 2.5.1-master/package.mo): time 0.001932/0.001932, allocations: 270.7 kB / 291.2 MB, free: 1.996 MB / 238.1 MB [/home/hudson/saved_omc/libraries/.openmodelica/libraries/BuildingSystems 2.0.0-master/Buildings/Airvolumes/Parameter/package.mo:5:3-5:34:writable] Warning: Got element f_alp that was not referenced in the package.order file. [/home/hudson/saved_omc/libraries/.openmodelica/libraries/BuildingSystems 2.0.0-master/Buildings/Airvolumes/Parameter/package.mo:6:3-6:35:writable] Warning: Elements in the package.mo-file need to be in the same relative order as the package.order file. Got element named f_lay but it was already added because it was not the next element in the list at that time. [/home/hudson/saved_omc/libraries/.openmodelica/libraries/BuildingSystems 2.0.0-master/Buildings/Airvolumes/Parameter/package.mo:6:3-6:35:writable] Warning: Got element f_lay that was not referenced in the package.order file. [/home/hudson/saved_omc/libraries/.openmodelica/libraries/BuildingSystems 2.0.0-master/Buildings/Airvolumes/Parameter/package.mo:7:3-7:37:writable] Warning: Elements in the package.mo-file need to be in the same relative order as the package.order file. Got element named f_loss but it was already added because it was not the next element in the list at that time. [/home/hudson/saved_omc/libraries/.openmodelica/libraries/BuildingSystems 2.0.0-master/Buildings/Airvolumes/Parameter/package.mo:7:3-7:37:writable] Warning: Got element f_loss that was not referenced in the package.order file. [/home/hudson/saved_omc/libraries/.openmodelica/libraries/BuildingSystems 2.0.0-master/Buildings/Airvolumes/Parameter/package.mo:8:3-8:33:writable] Warning: Elements in the package.mo-file need to be in the same relative order as the package.order file. Got element named f_pv but it was already added because it was not the next element in the list at that time. [/home/hudson/saved_omc/libraries/.openmodelica/libraries/BuildingSystems 2.0.0-master/Buildings/Airvolumes/Parameter/package.mo:8:3-8:33:writable] Warning: Got element f_pv that was not referenced in the package.order file. [/home/hudson/saved_omc/libraries/.openmodelica/libraries/BuildingSystems 2.0.0-master/Buildings/Airvolumes/Parameter/package.mo:2:1-34:14:writable] Warning: f_pv was referenced in the package.order file, but was not found in package.mo, f_pv/package.mo or f_pv.mo. Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/BuildingSystems 2.0.0-master/package.mo): time 0.8146/0.8146, allocations: 144.6 MB / 487 MB, free: 7.172 MB / 350.1 MB Notification: Performance of FrontEnd - loaded program: time 0.000412/0.0004121, allocations: 16.55 kB / 0.5684 GB, free: 38.23 MB / 430.1 MB Notification: Performance of FrontEnd - Absyn->SCode: time 0.1313/0.1317, allocations: 83.09 MB / 0.6495 GB, free: 3.488 MB / 446.1 MB Notification: Performance of NFInst.instantiate(BuildingSystems.Climate.Examples.TiltedRadiation): time 0.002932/0.1347, allocations: 2.501 MB / 0.652 GB, free: 0.9727 MB / 446.1 MB Notification: Performance of NFInst.instExpressions: time 0.003901/0.1386, allocations: 2.947 MB / 0.6548 GB, free: 14.03 MB / 462.1 MB Notification: Performance of NFInst.updateImplicitVariability: time 0.0001824/0.1388, allocations: 0 / 0.6548 GB, free: 14.03 MB / 462.1 MB Notification: Performance of NFTyping.typeComponents: time 0.0002287/0.1391, allocations: 51.61 kB / 0.6549 GB, free: 13.98 MB / 462.1 MB Notification: Performance of NFTyping.typeBindings: time 0.0008703/0.1399, allocations: 372.1 kB / 0.6552 GB, free: 13.62 MB / 462.1 MB Notification: Performance of NFTyping.typeClassSections: time 0.0006779/0.1406, allocations: 294.8 kB / 0.6555 GB, free: 13.34 MB / 462.1 MB Notification: Performance of NFFlatten.flatten: time 0.0004473/0.1411, allocations: 404.5 kB / 0.6559 GB, free: 12.94 MB / 462.1 MB Notification: Performance of NFFlatten.resolveConnections: time 0.0001802/0.1413, allocations: 99.25 kB / 0.656 GB, free: 12.84 MB / 462.1 MB Notification: Performance of NFEvalConstants.evaluate: time 0.0002685/0.1416, allocations: 240.4 kB / 0.6562 GB, free: 12.6 MB / 462.1 MB Notification: Performance of NFSimplifyModel.simplify: time 0.0003881/0.1419, allocations: 267.8 kB / 0.6565 GB, free: 12.34 MB / 462.1 MB Notification: Performance of NFPackage.collectConstants: time 5.721e-05/0.142, allocations: 24 kB / 0.6565 GB, free: 12.32 MB / 462.1 MB Notification: Performance of NFFlatten.collectFunctions: time 0.000735/0.1428, allocations: 448.3 kB / 0.6569 GB, free: 11.88 MB / 462.1 MB Notification: Performance of NFScalarize.scalarize: time 0.0001425/0.1429, allocations: 124.5 kB / 0.6571 GB, free: 11.76 MB / 462.1 MB Notification: Performance of NFVerifyModel.verify: time 9.536e-05/0.143, allocations: 113.4 kB / 0.6572 GB, free: 11.64 MB / 462.1 MB Notification: Performance of NFConvertDAE.convert: time 0.0007055/0.1437, allocations: 0.7017 MB / 0.6579 GB, free: 10.94 MB / 462.1 MB Notification: Performance of FrontEnd - DAE generated: time 2.815e-06/0.1437, allocations: 0.6875 kB / 0.6579 GB, free: 10.94 MB / 462.1 MB Notification: Performance of FrontEnd: time 1.332e-06/0.1437, allocations: 1.188 kB / 0.6579 GB, free: 10.94 MB / 462.1 MB Notification: Performance of Transformations before backend: time 6.172e-06/0.1438, allocations: 0 / 0.6579 GB, free: 10.94 MB / 462.1 MB Notification: Model statistics after passing the front-end and creating the data structures used by the back-end: * Number of equations: 109 * Number of variables: 109 Notification: Performance of Generate backend data structure: time 0.001656/0.1454, allocations: 0.7859 MB / 0.6586 GB, free: 10.11 MB / 462.1 MB Notification: Performance of prepare preOptimizeDAE: time 3.84e-05/0.1455, allocations: 8.719 kB / 0.6586 GB, free: 10.1 MB / 462.1 MB Notification: Performance of preOpt introduceOutputAliases (simulation): time 0.000113/0.1456, allocations: 86.53 kB / 0.6587 GB, free: 10 MB / 462.1 MB Notification: Performance of preOpt normalInlineFunction (simulation): time 0.003168/0.1488, allocations: 0.5731 MB / 0.6593 GB, free: 9.441 MB / 462.1 MB Notification: Performance of preOpt evaluateParameters (simulation): time 0.001255/0.15, allocations: 0.5573 MB / 0.6598 GB, free: 8.848 MB / 462.1 MB Notification: Performance of preOpt simplifyIfEquations (simulation): time 0.0001663/0.1502, allocations: 199.2 kB / 0.66 GB, free: 8.617 MB / 462.1 MB Notification: Performance of preOpt expandDerOperator (simulation): time 8.345e-05/0.1503, allocations: 47.94 kB / 0.6601 GB, free: 8.57 MB / 462.1 MB Notification: Performance of preOpt clockPartitioning (simulation): time 0.001342/0.1517, allocations: 0.6713 MB / 0.6607 GB, free: 7.879 MB / 462.1 MB Notification: Performance of preOpt findStateOrder (simulation): time 1.309e-05/0.1517, allocations: 3.984 kB / 0.6607 GB, free: 7.875 MB / 462.1 MB Notification: Performance of preOpt replaceEdgeChange (simulation): time 6.541e-05/0.1518, allocations: 16 kB / 0.6607 GB, free: 7.859 MB / 462.1 MB Notification: Performance of preOpt inlineArrayEqn (simulation): time 1.092e-05/0.1518, allocations: 12 kB / 0.6607 GB, free: 7.848 MB / 462.1 MB Notification: Performance of preOpt removeEqualRHS (simulation): time 0.001761/0.1535, allocations: 0.7689 MB / 0.6615 GB, free: 7.082 MB / 462.1 MB Notification: Performance of preOpt removeSimpleEquations (simulation): time 0.003335/0.1569, allocations: 1.735 MB / 0.6632 GB, free: 5.285 MB / 462.1 MB Notification: Performance of preOpt comSubExp (simulation): time 0.003035/0.1599, allocations: 1.016 MB / 0.6642 GB, free: 4.246 MB / 462.1 MB Notification: Performance of preOpt evalFunc (simulation): time 0.001667/0.1616, allocations: 1.769 MB / 0.6659 GB, free: 2.09 MB / 462.1 MB Notification: Performance of preOpt encapsulateWhenConditions (simulation): time 0.00105/0.1627, allocations: 463.4 kB / 0.6663 GB, free: 1.629 MB / 462.1 MB Notification: Performance of pre-optimization done (n=66): time 3.116e-06/0.1627, allocations: 0 / 0.6663 GB, free: 1.629 MB / 462.1 MB Notification: Performance of matching and sorting (n=66): time 0.002715/0.1654, allocations: 1.076 MB / 0.6674 GB, free: 0.5469 MB / 462.1 MB Notification: Performance of inlineWhenForInitialization (initialization): time 6.068e-05/0.1655, allocations: 111.4 kB / 0.6675 GB, free: 424 kB / 462.1 MB Notification: Performance of selectInitializationVariablesDAE (initialization): time 0.0004129/0.1659, allocations: 353.8 kB / 0.6678 GB, free: 64 kB / 462.1 MB Notification: Performance of collectPreVariables (initialization): time 7.076e-05/0.166, allocations: 41.7 kB / 0.6679 GB, free: 16 kB / 462.1 MB Notification: Performance of collectInitialEqns (initialization): time 0.0001689/0.1662, allocations: 217 kB / 0.6681 GB, free: 15.8 MB / 478.1 MB Notification: Performance of collectInitialBindings (initialization): time 0.0001769/0.1664, allocations: 212.8 kB / 0.6683 GB, free: 15.59 MB / 478.1 MB Notification: Performance of simplifyInitialFunctions (initialization): time 5.438e-05/0.1664, allocations: 16 kB / 0.6683 GB, free: 15.57 MB / 478.1 MB Notification: Performance of setup shared object (initialization): time 0.0001269/0.1666, allocations: 354.8 kB / 0.6686 GB, free: 15.21 MB / 478.1 MB Notification: Performance of preBalanceInitialSystem (initialization): time 0.0008131/0.1674, allocations: 313.8 kB / 0.6689 GB, free: 14.91 MB / 478.1 MB Notification: Performance of partitionIndependentBlocks (initialization): time 0.0008801/0.1683, allocations: 445.5 kB / 0.6694 GB, free: 14.44 MB / 478.1 MB Notification: Performance of analyzeInitialSystem (initialization): time 0.0008645/0.1692, allocations: 339.1 kB / 0.6697 GB, free: 14.11 MB / 478.1 MB Notification: Performance of solveInitialSystemEqSystem (initialization): time 4.488e-06/0.1692, allocations: 4 kB / 0.6697 GB, free: 14.1 MB / 478.1 MB Notification: Performance of matching and sorting (n=83) (initialization): time 0.002015/0.1712, allocations: 0.8637 MB / 0.6705 GB, free: 13.23 MB / 478.1 MB Notification: Performance of prepare postOptimizeDAE: time 2.282e-05/0.1712, allocations: 8 kB / 0.6705 GB, free: 13.22 MB / 478.1 MB Notification: Performance of postOpt simplifyComplexFunction (initialization): time 8.897e-06/0.1712, allocations: 7.922 kB / 0.6706 GB, free: 13.21 MB / 478.1 MB Notification: Performance of postOpt tearingSystem (initialization): time 1.904e-05/0.1713, allocations: 11.95 kB / 0.6706 GB, free: 13.2 MB / 478.1 MB Notification: Performance of postOpt solveSimpleEquations (initialization): time 0.001003/0.1723, allocations: 191.7 kB / 0.6707 GB, free: 13.02 MB / 478.1 MB Notification: Performance of postOpt calculateStrongComponentJacobians (initialization): time 1.512e-05/0.1723, allocations: 7.938 kB / 0.6708 GB, free: 13.01 MB / 478.1 MB Notification: Performance of postOpt simplifyAllExpressions (initialization): time 0.0007539/0.1731, allocations: 107.4 kB / 0.6709 GB, free: 12.9 MB / 478.1 MB Notification: Performance of postOpt collapseArrayExpressions (initialization): time 7.601e-05/0.1732, allocations: 31.97 kB / 0.6709 GB, free: 12.87 MB / 478.1 MB Notification: Model statistics after passing the back-end for initialization: * Number of independent subsystems: 11 * Number of states: 0 () * Number of discrete variables: 5 ($whenCondition1,$PRE.weatherData.weatherData.conTim.tNext,weatherData.weatherData.conTim.tNext,radiationFixed.outsidePolarCircle,radiationOneAxisTracked.outsidePolarCircle) * Number of discrete states: 0 () * Number of clocked states: 0 () * Top-level inputs: 0 Notification: Strong component statistics for initialization (83): * Single equations (assignments): 83 * Array equations: 0 * Algorithm blocks: 0 * Record equations: 0 * When equations: 0 * If-equations: 0 * Equation systems (linear and non-linear blocks): 0 * Torn equation systems: 0 * Mixed (continuous/discrete) equation systems: 0 Notification: Performance of prepare postOptimizeDAE: time 0.0002824/0.1734, allocations: 195.6 kB / 0.6711 GB, free: 12.67 MB / 478.1 MB Notification: Performance of postOpt lateInlineFunction (simulation): time 0.0001015/0.1735, allocations: 55.33 kB / 0.6711 GB, free: 12.62 MB / 478.1 MB Notification: Performance of postOpt wrapFunctionCalls (simulation): time 0.002796/0.1764, allocations: 1.131 MB / 0.6722 GB, free: 11.48 MB / 478.1 MB Notification: Performance of postOpt inlineArrayEqn (simulation): time 9.869e-06/0.1764, allocations: 8 kB / 0.6722 GB, free: 11.47 MB / 478.1 MB Notification: Performance of postOpt constantLinearSystem (simulation): time 6.873e-06/0.1764, allocations: 7.953 kB / 0.6722 GB, free: 11.46 MB / 478.1 MB Notification: Performance of postOpt simplifysemiLinear (simulation): time 1.408e-05/0.1764, allocations: 7.922 kB / 0.6723 GB, free: 11.45 MB / 478.1 MB Notification: Performance of postOpt removeSimpleEquations (simulation): time 0.003101/0.1795, allocations: 1.757 MB / 0.674 GB, free: 9.637 MB / 478.1 MB Notification: Performance of postOpt simplifyComplexFunction (simulation): time 4.097e-06/0.1795, allocations: 0 / 0.674 GB, free: 9.637 MB / 478.1 MB Notification: Performance of postOpt solveSimpleEquations (simulation): time 0.0009883/0.1805, allocations: 195.7 kB / 0.6742 GB, free: 9.445 MB / 478.1 MB Notification: Performance of postOpt tearingSystem (simulation): time 9.298e-06/0.1806, allocations: 7.938 kB / 0.6742 GB, free: 9.438 MB / 478.1 MB Notification: Performance of postOpt inputDerivativesUsed (simulation): time 6.525e-05/0.1806, allocations: 31.97 kB / 0.6742 GB, free: 9.406 MB / 478.1 MB Notification: Performance of postOpt calculateStrongComponentJacobians (simulation): time 6.292e-06/0.1806, allocations: 4 kB / 0.6742 GB, free: 9.402 MB / 478.1 MB Notification: Performance of postOpt calculateStateSetsJacobians (simulation): time 1.132e-06/0.1806, allocations: 0 / 0.6742 GB, free: 9.402 MB / 478.1 MB Notification: Performance of postOpt symbolicJacobian (simulation): time 0.002043/0.1827, allocations: 1.007 MB / 0.6752 GB, free: 8.383 MB / 478.1 MB Notification: Performance of postOpt removeConstants (simulation): time 0.0003176/0.183, allocations: 220.1 kB / 0.6754 GB, free: 8.148 MB / 478.1 MB Notification: Performance of postOpt simplifyTimeIndepFuncCalls (simulation): time 0.0001096/0.1831, allocations: 16 kB / 0.6754 GB, free: 8.133 MB / 478.1 MB Notification: Performance of postOpt simplifyAllExpressions (simulation): time 0.0006811/0.1838, allocations: 67.78 kB / 0.6755 GB, free: 8.066 MB / 478.1 MB Notification: Performance of postOpt findZeroCrossings (simulation): time 0.0001164/0.184, allocations: 60.91 kB / 0.6755 GB, free: 8.004 MB / 478.1 MB Notification: Performance of postOpt collapseArrayExpressions (simulation): time 6.83e-05/0.184, allocations: 31.98 kB / 0.6756 GB, free: 7.973 MB / 478.1 MB Notification: Performance of sorting global known variables: time 0.0002599/0.1843, allocations: 247.2 kB / 0.6758 GB, free: 7.734 MB / 478.1 MB Notification: Performance of sort global known variables: time 1.613e-06/0.1843, allocations: 0 / 0.6758 GB, free: 7.734 MB / 478.1 MB Notification: Performance of remove unused functions: time 0.000718/0.185, allocations: 227.8 kB / 0.676 GB, free: 7.512 MB / 478.1 MB Notification: Model statistics after passing the back-end for simulation: * Number of independent subsystems: 1 * Number of states: 0 () * Number of discrete variables: 2 ($whenCondition1,weatherData.weatherData.conTim.tNext) * Number of discrete states: 1 (weatherData.weatherData.conTim.tNext) * Number of clocked states: 0 () * Top-level inputs: 0 Notification: Strong component statistics for simulation (95): * Single equations (assignments): 94 * Array equations: 0 * Algorithm blocks: 0 * Record equations: 0 * When equations: 1 * If-equations: 0 * Equation systems (linear and non-linear blocks): 0 * Torn equation systems: 0 * Mixed (continuous/discrete) equation systems: 0 Notification: Performance of Backend phase and start with SimCode phase: time 0.003338/0.1884, allocations: 1.96 MB / 0.6779 GB, free: 5.676 MB / 478.1 MB Notification: Performance of simCode: created initialization part: time 0.001899/0.1903, allocations: 0.8111 MB / 0.6787 GB, free: 4.867 MB / 478.1 MB Notification: Performance of simCode: created event and clocks part: time 4.529e-06/0.1903, allocations: 7.938 kB / 0.6787 GB, free: 4.859 MB / 478.1 MB Notification: Performance of simCode: created simulation system equations: time 0.0009683/0.1913, allocations: 473.7 kB / 0.6792 GB, free: 4.398 MB / 478.1 MB Notification: Performance of simCode: created of all other equations (e.g. parameter, nominal, assert, etc): time 0.0003732/0.1917, allocations: 49.42 kB / 0.6792 GB, free: 4.348 MB / 478.1 MB Notification: Performance of simCode: created linear, non-linear and system jacobian parts: time 0.00678/0.1985, allocations: 4.989 MB / 0.6841 GB, free: 15.27 MB / 494.1 MB Notification: Performance of simCode: some other stuff during SimCode phase: time 0.0003838/0.1989, allocations: 0.8859 MB / 0.685 GB, free: 14.35 MB / 494.1 MB Notification: Performance of simCode: alias equations: time 0.0008527/0.1997, allocations: 168.6 kB / 0.6851 GB, free: 14.18 MB / 494.1 MB Notification: Performance of simCode: all other stuff during SimCode phase: time 0.0004251/0.2002, allocations: 219.2 kB / 0.6853 GB, free: 13.97 MB / 494.1 MB Notification: Performance of SimCode: time 5.21e-07/0.2002, allocations: 0 / 0.6853 GB, free: 13.97 MB / 494.1 MB Notification: Performance of buildModelFMU: Generate the FMI files: time 0.02648/0.2267, allocations: 13.5 MB / 0.6985 GB, free: 0.6641 MB / 494.1 MB Notification: Performance of buildModelFMU: configured platform static using cached values: time 0.000163/0.2269, allocations: 222.9 kB / 0.6987 GB, free: 436 kB / 494.1 MB Notification: Performance of buildModelFMU: Generate platform static: time 2.187/2.414, allocations: 7.516 kB / 0.6987 GB, free: 432 kB / 494.1 MB (rm -f BuildingSystems_BuildingSystems.Climate.Examples.TiltedRadiation.pipe ; mkfifo BuildingSystems_BuildingSystems.Climate.Examples.TiltedRadiation.pipe ; head -c 1048576 < BuildingSystems_BuildingSystems.Climate.Examples.TiltedRadiation.pipe >> ../files/BuildingSystems_BuildingSystems.Climate.Examples.TiltedRadiation.sim & /home/hudson/saved_omc/OMSimulator/install/linux/bin/OMSimulator --tempDir=temp_BuildingSystems_BuildingSystems_Climate_Examples_TiltedRadiation_fmu --startTime=0 --stopTime=3.1536e+07 --timeout=50 --tolerance=1e-06 BuildingSystems_BuildingSystems_Climate_Examples_TiltedRadiation.fmu > BuildingSystems_BuildingSystems.Climate.Examples.TiltedRadiation.pipe 2>&1) Environment - environmentSimulation: