Running: ./testmodel.py --libraries=/home/hudson/saved_omc/libraries/.openmodelica/libraries/ --ompython_omhome=/usr Modelica_3.2.1_Modelica.Electrical.PowerConverters.Examples.DCDC.ChopperStepUp.ChopperStepUp_R.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 3.2.3+maint.om/package.mo", uses=false)
Using package Modelica with version 3.2.3 (/home/hudson/saved_omc/libraries/.openmodelica/libraries/Modelica 3.2.3+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: translateModel(Modelica.Electrical.PowerConverters.Examples.DCDC.ChopperStepUp.ChopperStepUp_R,tolerance=1e-06,outputFormat="empty",numberOfIntervals=4000,variableFilter="",fileNamePrefix="Modelica_3.2.1_Modelica.Electrical.PowerConverters.Examples.DCDC.ChopperStepUp.ChopperStepUp_R")
translateModel(Modelica.Electrical.PowerConverters.Examples.DCDC.ChopperStepUp.ChopperStepUp_R,tolerance=1e-06,outputFormat="empty",numberOfIntervals=4000,variableFilter="",fileNamePrefix="Modelica_3.2.1_Modelica.Electrical.PowerConverters.Examples.DCDC.ChopperStepUp.ChopperStepUp_R")
Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/ModelicaServices 4.0.0+maint.om/package.mo): time 0.001127/0.001127, allocations: 100.2 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 0.001378/0.001378, 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 3.2.3+maint.om/package.mo): time 1.659/1.659, allocations: 205.4 MB / 222.1 MB, free: 5.656 MB / 174.1 MB
Notification: Modelica requested package Complex of version 3.2.3. Complex 4.0.0 is used instead which states that it is fully compatible without conversion script needed.
Notification: Modelica requested package ModelicaServices of version 3.2.3. ModelicaServices 4.0.0 is used instead which states that it is fully compatible without conversion script needed.
Notification: Performance of FrontEnd - loaded program: time 0.0004735/0.0004737, allocations: 8 kB / 278.9 MB, free: 12.83 MB / 238.1 MB
Notification: Performance of FrontEnd - Absyn->SCode: time 0.2756/0.2761, allocations: 47.59 MB / 326.5 MB, free: 1.625 MB / 254.1 MB
Notification: Performance of NFInst.instantiate(Modelica.Electrical.PowerConverters.Examples.DCDC.ChopperStepUp.ChopperStepUp_R): time 0.003431/0.2796, allocations: 3.064 MB / 329.5 MB, free: 15.26 MB / 270.1 MB
Notification: Performance of NFInst.instExpressions: time 0.001786/0.2814, allocations: 0.9639 MB / 330.5 MB, free: 14.47 MB / 270.1 MB
Notification: Performance of NFInst.updateImplicitVariability: time 0.0002363/0.2817, allocations: 11.16 kB / 330.5 MB, free: 14.47 MB / 270.1 MB
Notification: Performance of NFTyping.typeComponents: time 0.0001678/0.2819, allocations: 48.73 kB / 330.6 MB, free: 14.43 MB / 270.1 MB
Notification: Performance of NFTyping.typeBindings: time 0.0002831/0.2821, allocations: 154.4 kB / 330.7 MB, free: 14.29 MB / 270.1 MB
Notification: Performance of NFTyping.typeClassSections: time 0.0005099/0.2827, allocations: 145 kB / 330.8 MB, free: 14.18 MB / 270.1 MB
Notification: Performance of NFFlatten.flatten: time 0.000482/0.2832, allocations: 402.9 kB / 331.2 MB, free: 13.92 MB / 270.1 MB
Notification: Performance of NFFlatten.resolveConnections: time 0.0003426/0.2835, allocations: 180.8 kB / 331.4 MB, free: 13.81 MB / 270.1 MB
Notification: Performance of NFEvalConstants.evaluate: time 0.000281/0.2838, allocations: 173.7 kB / 331.6 MB, free: 13.72 MB / 270.1 MB
Notification: Performance of NFSimplifyModel.simplify: time 0.0002609/0.2841, allocations: 204.6 kB / 331.8 MB, free: 13.58 MB / 270.1 MB
Notification: Performance of NFPackage.collectConstants: time 6.103e-05/0.2841, allocations: 23.38 kB / 331.8 MB, free: 13.58 MB / 270.1 MB
Notification: Performance of NFFlatten.collectFunctions: time 6.782e-05/0.2842, allocations: 23.56 kB / 331.8 MB, free: 13.58 MB / 270.1 MB
Notification: Performance of NFScalarize.scalarize: time 0.0001053/0.2843, allocations: 88.02 kB / 331.9 MB, free: 13.51 MB / 270.1 MB
Notification: Performance of NFVerifyModel.verify: time 0.0001296/0.2845, allocations: 119.7 kB / 332 MB, free: 13.43 MB / 270.1 MB
Notification: Performance of NFConvertDAE.convert: time 0.0005614/0.285, allocations: 484.7 kB / 332.5 MB, free: 13.06 MB / 270.1 MB
Notification: Performance of FrontEnd - DAE generated: time 2.615e-06/0.285, allocations: 4 kB / 332.5 MB, free: 13.05 MB / 270.1 MB
Notification: Performance of FrontEnd: time 1.944e-06/0.285, allocations: 1.188 kB / 332.5 MB, free: 13.05 MB / 270.1 MB
Notification: Performance of Transformations before backend: time 7.625e-06/0.2851, allocations: 0 / 332.5 MB, free: 13.05 MB / 270.1 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 0.00147/0.2865, allocations: 0.76 MB / 333.3 MB, free: 12.41 MB / 270.1 MB
Notification: Performance of prepare preOptimizeDAE: time 3.846e-05/0.2866, allocations: 9.781 kB / 333.3 MB, free: 12.41 MB / 270.1 MB
Notification: Performance of preOpt normalInlineFunction (simulation): time 0.0001108/0.2867, allocations: 56.69 kB / 333.3 MB, free: 12.38 MB / 270.1 MB
Notification: Performance of preOpt evaluateParameters (simulation): time 0.000547/0.2873, allocations: 387.2 kB / 333.7 MB, free: 12.03 MB / 270.1 MB
Notification: Performance of preOpt simplifyIfEquations (simulation): time 7.199e-05/0.2873, allocations: 39.78 kB / 333.8 MB, free: 12.01 MB / 270.1 MB
Notification: Performance of preOpt expandDerOperator (simulation): time 8.356e-05/0.2874, allocations: 50.98 kB / 333.8 MB, free: 11.99 MB / 270.1 MB
Notification: Performance of preOpt clockPartitioning (simulation): time 0.000869/0.2883, allocations: 471.8 kB / 334.3 MB, free: 11.7 MB / 270.1 MB
Notification: Performance of preOpt findStateOrder (simulation): time 2.187e-05/0.2883, allocations: 7.922 kB / 334.3 MB, free: 11.69 MB / 270.1 MB
Notification: Performance of preOpt replaceEdgeChange (simulation): time 5.364e-05/0.2884, allocations: 21.22 kB / 334.3 MB, free: 11.67 MB / 270.1 MB
Notification: Performance of preOpt inlineArrayEqn (simulation): time 1.708e-05/0.2884, allocations: 11.12 kB / 334.3 MB, free: 11.67 MB / 270.1 MB
Notification: Performance of preOpt removeEqualRHS (simulation): time 0.0006592/0.2891, allocations: 329.8 kB / 334.6 MB, free: 11.36 MB / 270.1 MB
Notification: Performance of preOpt removeSimpleEquations (simulation): time 0.002359/0.2915, allocations: 1.706 MB / 336.3 MB, free: 9.562 MB / 270.1 MB
Notification: Performance of preOpt comSubExp (simulation): time 0.0008089/0.2923, allocations: 350.8 kB / 336.7 MB, free: 9.211 MB / 270.1 MB
Notification: Performance of preOpt evalFunc (simulation): time 3.3e-05/0.2923, allocations: 4 kB / 336.7 MB, free: 9.207 MB / 270.1 MB
Notification: Performance of preOpt encapsulateWhenConditions (simulation): time 0.0005281/0.2929, allocations: 269 kB / 336.9 MB, free: 8.926 MB / 270.1 MB
Notification: Performance of pre-optimization done (n=40): time 1.783e-06/0.2929, allocations: 0 / 336.9 MB, free: 8.926 MB / 270.1 MB
Notification: Performance of matching and sorting (n=40): time 0.001557/0.2944, allocations: 0.652 MB / 337.6 MB, free: 8.246 MB / 270.1 MB
Notification: Performance of inlineWhenForInitialization (initialization): time 7.531e-05/0.2945, allocations: 114.8 kB / 337.7 MB, free: 8.109 MB / 270.1 MB
Notification: Performance of selectInitializationVariablesDAE (initialization): time 0.0003713/0.2949, allocations: 357.5 kB / 338.1 MB, free: 7.746 MB / 270.1 MB
Notification: Performance of collectPreVariables (initialization): time 4.397e-05/0.295, allocations: 41.69 kB / 338.1 MB, free: 7.699 MB / 270.1 MB
Notification: Performance of collectInitialEqns (initialization): time 0.0001615/0.2951, allocations: 232.3 kB / 338.3 MB, free: 7.465 MB / 270.1 MB
Notification: Performance of collectInitialBindings (initialization): time 9.277e-05/0.2952, allocations: 118.3 kB / 338.4 MB, free: 7.348 MB / 270.1 MB
Notification: Performance of simplifyInitialFunctions (initialization): time 2.631e-05/0.2953, allocations: 12 kB / 338.5 MB, free: 7.336 MB / 270.1 MB
Notification: Performance of setup shared object (initialization): time 0.0001588/0.2954, allocations: 350.8 kB / 338.8 MB, free: 6.984 MB / 270.1 MB
Notification: Performance of preBalanceInitialSystem (initialization): time 0.0002502/0.2957, allocations: 125.1 kB / 338.9 MB, free: 6.859 MB / 270.1 MB
Notification: Performance of partitionIndependentBlocks (initialization): time 0.000414/0.2961, allocations: 257 kB / 339.2 MB, free: 6.559 MB / 270.1 MB
Notification: Performance of analyzeInitialSystem (initialization): time 0.000297/0.2964, allocations: 178 kB / 339.3 MB, free: 6.379 MB / 270.1 MB
Notification: Performance of solveInitialSystemEqSystem (initialization): time 3.176e-06/0.2964, allocations: 0 / 339.3 MB, free: 6.379 MB / 270.1 MB
Notification: Performance of matching and sorting (n=57) (initialization): time 0.001008/0.2974, allocations: 0.5111 MB / 339.9 MB, free: 5.852 MB / 270.1 MB
Notification: Performance of prepare postOptimizeDAE: time 0.0007014/0.2982, allocations: 1.428 MB / 341.3 MB, free: 4.309 MB / 270.1 MB
Notification: Performance of postOpt simplifyComplexFunction (initialization): time 9.468e-06/0.2982, allocations: 4 kB / 341.3 MB, free: 4.305 MB / 270.1 MB
Notification: Performance of postOpt tearingSystem (initialization): time 0.0002853/0.2985, allocations: 68.81 kB / 341.4 MB, free: 4.234 MB / 270.1 MB
Notification: Performance of postOpt solveSimpleEquations (initialization): time 0.0002976/0.2988, allocations: 83.83 kB / 341.4 MB, free: 4.152 MB / 270.1 MB
Notification: Performance of postOpt calculateStrongComponentJacobians (initialization): time 0.001905/0.3007, allocations: 1.726 MB / 343.2 MB, free: 2.297 MB / 270.1 MB
Notification: Performance of postOpt simplifyAllExpressions (initialization): time 0.0003354/0.301, allocations: 55.73 kB / 343.2 MB, free: 2.242 MB / 270.1 MB
Notification: Performance of postOpt collapseArrayExpressions (initialization): time 3.564e-05/0.3011, allocations: 20 kB / 343.2 MB, free: 2.223 MB / 270.1 MB
Notification: Performance of prepare postOptimizeDAE: time 7.625e-06/0.3011, allocations: 4 kB / 343.2 MB, free: 2.219 MB / 270.1 MB
Notification: Performance of postOpt replaceHomotopyWithSimplified (initialization): time 0.0008154/0.3019, allocations: 441.6 kB / 343.7 MB, free: 1.777 MB / 270.1 MB
Notification: Performance of postOpt simplifyComplexFunction (initialization): time 5.49e-06/0.3019, allocations: 4 kB / 343.7 MB, free: 1.773 MB / 270.1 MB
Notification: Performance of postOpt tearingSystem (initialization): time 0.0001858/0.3021, allocations: 72.77 kB / 343.7 MB, free: 1.699 MB / 270.1 MB
Notification: Performance of postOpt solveSimpleEquations (initialization): time 0.0002556/0.3024, allocations: 79.83 kB / 343.8 MB, free: 1.621 MB / 270.1 MB
Notification: Performance of postOpt calculateStrongComponentJacobians (initialization): time 0.001543/0.3039, allocations: 1.702 MB / 345.5 MB, free: 15.78 MB / 286.1 MB
Notification: Performance of postOpt simplifyAllExpressions (initialization): time 0.0002928/0.3043, allocations: 59.59 kB / 345.6 MB, free: 15.72 MB / 286.1 MB
Notification: Performance of postOpt collapseArrayExpressions (initialization): time 2.799e-05/0.3043, allocations: 16.5 kB / 345.6 MB, free: 15.71 MB / 286.1 MB
Notification: Model statistics after passing the back-end for initialization:
 * Number of independent subsystems: 16
 * Number of states: 0 ()
 * Number of discrete variables: 21 ($PRE.signalPWM.zeroOrderHold.firstTrigger,signalPWM.zeroOrderHold.firstTrigger,$PRE.meanCurrent.y,meanCurrent.y,$PRE.meanVoltage.y,meanVoltage.y,$whenCondition2,$whenCondition1,$whenCondition4,signalPWM.zeroOrderHold.sampleTrigger,signalPWM.zeroOrderHold.ySample,$whenCondition3,chopperStepUp.andCondition_p.y,chopperStepUp.transistor.off,chopperStepUp.diode.off,signalPWM.notFire,$PRE.signalPWM.zeroOrderHold.ySample,$PRE.signalPWM.sawtooth.T_start,signalPWM.sawtooth.T_start,$PRE.signalPWM.sawtooth.count,signalPWM.sawtooth.count)
 * Number of discrete states: 0 ()
 * Number of clocked states: 0 ()
 * Top-level inputs: 0
Notification: Strong component statistics for initialization (49):
 * Single equations (assignments): 47
 * Array equations: 0
 * Algorithm blocks: 1
 * Record equations: 0
 * When equations: 0
 * If-equations: 0
 * Equation systems (linear and non-linear blocks): 0
 * Torn equation systems: 1
 * Mixed (continuous/discrete) equation systems: 0
Notification: Torn system details for strict tearing set:
 * Linear torn systems: 0
 * Non-linear torn systems: 1 {2 6}
Notification: Performance of prepare postOptimizeDAE: time 0.0004341/0.3047, allocations: 255.2 kB / 345.8 MB, free: 15.45 MB / 286.1 MB
Notification: Performance of postOpt lateInlineFunction (simulation): time 6.456e-05/0.3048, allocations: 39.53 kB / 345.9 MB, free: 15.41 MB / 286.1 MB
Notification: Performance of postOpt wrapFunctionCalls (simulation): time 9.171e-05/0.3049, allocations: 52.12 kB / 345.9 MB, free: 15.36 MB / 286.1 MB
Notification: Performance of postOpt inlineArrayEqn (simulation): time 4.408e-06/0.3049, allocations: 11.94 kB / 345.9 MB, free: 15.34 MB / 286.1 MB
Notification: Performance of postOpt constantLinearSystem (simulation): time 5.931e-06/0.3049, allocations: 3.984 kB / 346 MB, free: 15.34 MB / 286.1 MB
Notification: Performance of postOpt simplifysemiLinear (simulation): time 7.905e-06/0.3049, allocations: 3.953 kB / 346 MB, free: 15.34 MB / 286.1 MB
Notification: Performance of postOpt removeSimpleEquations (simulation): time 0.001609/0.3066, allocations: 0.9811 MB / 346.9 MB, free: 14.29 MB / 286.1 MB
Notification: Performance of postOpt simplifyComplexFunction (simulation): time 2.525e-06/0.3066, allocations: 0 / 346.9 MB, free: 14.29 MB / 286.1 MB
Notification: Performance of postOpt solveSimpleEquations (simulation): time 0.0002589/0.3068, allocations: 63.89 kB / 347 MB, free: 14.23 MB / 286.1 MB
Notification: Performance of postOpt tearingSystem (simulation): time 0.000194/0.307, allocations: 56.83 kB / 347.1 MB, free: 14.17 MB / 286.1 MB
Notification: Performance of postOpt inputDerivativesUsed (simulation): time 3.392e-05/0.3071, allocations: 11.98 kB / 347.1 MB, free: 14.16 MB / 286.1 MB
Notification: Performance of postOpt calculateStrongComponentJacobians (simulation): time 0.001622/0.3087, allocations: 1.71 MB / 348.8 MB, free: 12.31 MB / 286.1 MB
Notification: Performance of postOpt calculateStateSetsJacobians (simulation): time 1.754e-06/0.3087, allocations: 0 / 348.8 MB, free: 12.31 MB / 286.1 MB
Notification: Performance of postOpt symbolicJacobian (simulation): time 0.001063/0.3098, allocations: 0.6623 MB / 349.4 MB, free: 11.62 MB / 286.1 MB
Notification: Performance of postOpt removeConstants (simulation): time 0.0001678/0.31, allocations: 148.6 kB / 349.6 MB, free: 11.46 MB / 286.1 MB
Notification: Performance of postOpt simplifyTimeIndepFuncCalls (simulation): time 6.019e-05/0.31, allocations: 8 kB / 349.6 MB, free: 11.45 MB / 286.1 MB
Notification: Performance of postOpt simplifyAllExpressions (simulation): time 0.0002777/0.3103, allocations: 35.97 kB / 349.6 MB, free: 11.41 MB / 286.1 MB
Notification: Performance of postOpt findZeroCrossings (simulation): time 0.0001044/0.3104, allocations: 35.95 kB / 349.7 MB, free: 11.38 MB / 286.1 MB
Notification: Performance of postOpt collapseArrayExpressions (simulation): time 3.456e-05/0.3105, allocations: 15.98 kB / 349.7 MB, free: 11.36 MB / 286.1 MB
Notification: Performance of sorting global known variables: time 0.0002617/0.3108, allocations: 239.2 kB / 349.9 MB, free: 11.13 MB / 286.1 MB
Notification: Performance of sort global known variables: time 4.11e-07/0.3108, allocations: 0 / 349.9 MB, free: 11.13 MB / 286.1 MB
Notification: Performance of remove unused functions: time 0.0009113/0.3117, allocations: 227.3 kB / 350.1 MB, free: 10.91 MB / 286.1 MB
Notification: Model statistics after passing the back-end for simulation:
 * Number of independent subsystems: 2
 * Number of states: 4 (meanCurrent.x,meanVoltage.x,inductorSource.i,capacitor.v)
 * Number of discrete variables: 15 (signalPWM.zeroOrderHold.sampleTrigger,$whenCondition4,$whenCondition3,$whenCondition2,$whenCondition1,chopperStepUp.andCondition_p.y,chopperStepUp.transistor.off,chopperStepUp.diode.off,signalPWM.notFire,signalPWM.zeroOrderHold.firstTrigger,signalPWM.zeroOrderHold.ySample,signalPWM.sawtooth.T_start,signalPWM.sawtooth.count,meanCurrent.y,meanVoltage.y)
 * Number of discrete states: 4 (signalPWM.sawtooth.count,meanCurrent.x,meanVoltage.x,signalPWM.zeroOrderHold.ySample)
 * Number of clocked states: 0 ()
 * Top-level inputs: 0
Notification: Strong component statistics for simulation (33):
 * Single equations (assignments): 26
 * Array equations: 0
 * Algorithm blocks: 0
 * Record equations: 0
 * When equations: 6
 * If-equations: 0
 * Equation systems (linear and non-linear blocks): 0
 * Torn equation systems: 1
 * Mixed (continuous/discrete) equation systems: 0
Notification: Torn system details for strict tearing set:
 * Linear torn systems: 0
 * Non-linear torn systems: 1 {2 6}
Notification: Performance of Backend phase and start with SimCode phase: time 0.0002284/0.3119, allocations: 119.5 kB / 350.2 MB, free: 10.79 MB / 286.1 MB
Notification: Performance of simCode: created initialization part: time 0.00154/0.3135, allocations: 0.8994 MB / 351.1 MB, free: 9.836 MB / 286.1 MB
Notification: Performance of simCode: created event and clocks part: time 2.575e-06/0.3135, allocations: 0 / 351.1 MB, free: 9.836 MB / 286.1 MB
Notification: Performance of simCode: created simulation system equations: time 0.000494/0.314, allocations: 331.3 kB / 351.5 MB, free: 9.5 MB / 286.1 MB
Notification: Performance of simCode: created of all other equations (e.g. parameter, nominal, assert, etc): time 0.0004262/0.3144, allocations: 77.67 kB / 351.5 MB, free: 9.426 MB / 286.1 MB
Notification: Performance of simCode: created linear, non-linear and system jacobian parts: time 0.001872/0.3163, allocations: 1.141 MB / 352.7 MB, free: 8.254 MB / 286.1 MB
Notification: Performance of simCode: some other stuff during SimCode phase: time 0.0004532/0.3168, allocations: 0.847 MB / 353.5 MB, free: 7.379 MB / 286.1 MB
Notification: Performance of simCode: alias equations: time 0.0001854/0.317, allocations: 43.34 kB / 353.6 MB, free: 7.336 MB / 286.1 MB
Notification: Performance of simCode: all other stuff during SimCode phase: time 8.081e-05/0.317, allocations: 39.42 kB / 353.6 MB, free: 7.297 MB / 286.1 MB
Notification: Performance of SimCode: time 3.61e-07/0.3171, allocations: 0 / 353.6 MB, free: 7.297 MB / 286.1 MB
Notification: Performance of Templates: time 0.01119/0.3282, allocations: 6.06 MB / 359.7 MB, free: 1.234 MB / 286.1 MB
make -j1 -f Modelica_3.2.1_Modelica.Electrical.PowerConverters.Examples.DCDC.ChopperStepUp.ChopperStepUp_R.makefile
Environment - environmentSimulation:
(rm -f Modelica_3.2.1_Modelica.Electrical.PowerConverters.Examples.DCDC.ChopperStepUp.ChopperStepUp_R.pipe ; mkfifo Modelica_3.2.1_Modelica.Electrical.PowerConverters.Examples.DCDC.ChopperStepUp.ChopperStepUp_R.pipe ; head -c 1048576 < Modelica_3.2.1_Modelica.Electrical.PowerConverters.Examples.DCDC.ChopperStepUp.ChopperStepUp_R.pipe >> ../files/Modelica_3.2.1_Modelica.Electrical.PowerConverters.Examples.DCDC.ChopperStepUp.ChopperStepUp_R.sim & ./Modelica_3.2.1_Modelica.Electrical.PowerConverters.Examples.DCDC.ChopperStepUp.ChopperStepUp_R  -abortSlowSimulation -alarm=480 -lv LOG_STATS > Modelica_3.2.1_Modelica.Electrical.PowerConverters.Examples.DCDC.ChopperStepUp.ChopperStepUp_R.pipe 2>&1)
Environment - environmentSimulation: