Running: ./testmodel.py --libraries=/home/hudson/saved_omc/libraries/.openmodelica/libraries --ompython_omhome=/usr Buildings_latest_Buildings.Fluid.Movers.Validation.Pump_y_stratos.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/Buildings 11.0.0-master/package.mo", uses=false) Using package Buildings with version 11.0.0 (/home/hudson/saved_omc/libraries/.openmodelica/libraries/Buildings 11.0.0-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: translateModel(Buildings.Fluid.Movers.Validation.Pump_y_stratos,tolerance=1e-08,outputFormat="mat",numberOfIntervals=5000,variableFilter="time|pump1.m_flow|pump2.m_flow|pump3.m_flow|pump4.m_flow|pump5.m_flow|forcedPump1.dp|forcedPump2.dp|forcedPump3.dp|forcedPump4.dp|forcedPump5.dp|pump1.P|pump2.P|pump3.P|pump4.P|pump5.P",fileNamePrefix="Buildings_latest_Buildings.Fluid.Movers.Validation.Pump_y_stratos") translateModel(Buildings.Fluid.Movers.Validation.Pump_y_stratos,tolerance=1e-08,outputFormat="mat",numberOfIntervals=5000,variableFilter="time|pump1.m_flow|pump2.m_flow|pump3.m_flow|pump4.m_flow|pump5.m_flow|forcedPump1.dp|forcedPump2.dp|forcedPump3.dp|forcedPump4.dp|forcedPump5.dp|pump1.P|pump2.P|pump3.P|pump4.P|pump5.P",fileNamePrefix="Buildings_latest_Buildings.Fluid.Movers.Validation.Pump_y_stratos") Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/ModelicaServices 4.0.0+maint.om/package.mo): time 0.001485/0.001485, allocations: 103 kB / 16.35 MB, free: 5.824 MB / 14.72 MB Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Complex 4.0.0+maint.om/package.mo): time 0.001768/0.001768, allocations: 193.9 kB / 17.29 MB, free: 5.48 MB / 14.72 MB Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Modelica 4.0.0+maint.om/package.mo): time 1.294/1.294, allocations: 222.9 MB / 241 MB, free: 15.14 MB / 206.1 MB Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Buildings 11.0.0-master/package.mo): time 2.397/2.397, allocations: 442.6 MB / 0.7165 GB, free: 14.62 MB / 0.5919 GB Notification: Performance of FrontEnd - loaded program: time 0.001288/0.001288, allocations: 70.36 kB / 0.8773 GB, free: 10.95 MB / 0.6544 GB Notification: Performance of FrontEnd - Absyn->SCode: time 0.31/0.3113, allocations: 153 MB / 1.027 GB, free: 2.039 MB / 0.795 GB Notification: Performance of NFInst.instantiate(Buildings.Fluid.Movers.Validation.Pump_y_stratos): time 0.6343/0.9456, allocations: 212.3 MB / 1.234 GB, free: 8.832 MB / 0.9356 GB Notification: Performance of NFInst.instExpressions: time 0.1068/1.052, allocations: 69.92 MB / 1.302 GB, free: 2.742 MB / 0.9981 GB Notification: Performance of NFInst.updateImplicitVariability: time 0.0144/1.067, allocations: 366.1 kB / 1.303 GB, free: 2.383 MB / 0.9981 GB Notification: Performance of NFTyping.typeComponents: time 0.05013/1.117, allocations: 30.34 MB / 1.332 GB, free: 3.988 MB / 1.029 GB Notification: Performance of NFTyping.typeBindings: time 0.03069/1.148, allocations: 10.85 MB / 1.343 GB, free: 9.086 MB / 1.045 GB Notification: Performance of NFTyping.typeClassSections: time 0.0212/1.169, allocations: 8.613 MB / 1.351 GB, free: 0.5156 MB / 1.045 GB Notification: Performance of NFFlatten.flatten: time 0.085/1.254, allocations: 58.13 MB / 1.408 GB, free: 6.305 MB / 1.107 GB Notification: Performance of NFFlatten.resolveConnections: time 0.01529/1.269, allocations: 8.47 MB / 1.416 GB, free: 13.71 MB / 1.123 GB Notification: Performance of NFEvalConstants.evaluate: time 0.02052/1.29, allocations: 9.22 MB / 1.425 GB, free: 4.484 MB / 1.123 GB Notification: Performance of NFSimplifyModel.simplify: time 0.01273/1.303, allocations: 7.621 MB / 1.433 GB, free: 12.83 MB / 1.139 GB Notification: Performance of NFPackage.collectConstants: time 0.004644/1.307, allocations: 1.082 MB / 1.434 GB, free: 11.75 MB / 1.139 GB Notification: Performance of NFFlatten.collectFunctions: time 0.01281/1.32, allocations: 3.991 MB / 1.438 GB, free: 7.754 MB / 1.139 GB Notification: Performance of NFScalarize.scalarize: time 0.006989/1.327, allocations: 5.383 MB / 1.443 GB, free: 2.355 MB / 1.139 GB Notification: Performance of NFVerifyModel.verify: time 0.01487/1.342, allocations: 7.921 MB / 1.451 GB, free: 10.39 MB / 1.154 GB Notification: Performance of NFConvertDAE.convert: time 0.03073/1.373, allocations: 21.99 MB / 1.472 GB, free: 4.336 MB / 1.17 GB Notification: Performance of FrontEnd - DAE generated: time 4.348e-06/1.373, allocations: 3.938 kB / 1.472 GB, free: 4.332 MB / 1.17 GB Notification: Performance of FrontEnd: time 1.042e-06/1.373, allocations: 0 / 1.472 GB, free: 4.332 MB / 1.17 GB Notification: Performance of Transformations before backend: time 0.0006344/1.374, allocations: 0 / 1.472 GB, free: 4.332 MB / 1.17 GB Notification: Model statistics after passing the front-end and creating the data structures used by the back-end: * Number of equations: 1254 * Number of variables: 1254 Notification: Performance of Generate backend data structure: time 0.04363/1.417, allocations: 16.47 MB / 1.488 GB, free: 3.645 MB / 1.186 GB Notification: Performance of prepare preOptimizeDAE: time 5.146e-05/1.417, allocations: 8.031 kB / 1.488 GB, free: 3.637 MB / 1.186 GB Notification: Performance of preOpt normalInlineFunction (simulation): time 0.02739/1.445, allocations: 4.781 MB / 1.493 GB, free: 14.83 MB / 1.201 GB Notification: Performance of preOpt evaluateParameters (simulation): time 0.04502/1.49, allocations: 21.94 MB / 1.514 GB, free: 8.773 MB / 1.217 GB Notification: Performance of preOpt simplifyIfEquations (simulation): time 0.0005455/1.49, allocations: 429.7 kB / 1.515 GB, free: 8.352 MB / 1.217 GB Notification: Performance of preOpt expandDerOperator (simulation): time 0.00238/1.493, allocations: 0.5624 MB / 1.515 GB, free: 7.789 MB / 1.217 GB Notification: Performance of preOpt clockPartitioning (simulation): time 0.02006/1.513, allocations: 7.759 MB / 1.523 GB, free: 15.78 MB / 1.232 GB Notification: Performance of preOpt findStateOrder (simulation): time 0.0001746/1.513, allocations: 7.844 kB / 1.523 GB, free: 15.77 MB / 1.232 GB Notification: Performance of preOpt replaceEdgeChange (simulation): time 0.001345/1.514, allocations: 204 kB / 1.523 GB, free: 15.57 MB / 1.232 GB Notification: Performance of preOpt inlineArrayEqn (simulation): time 0.0001758/1.515, allocations: 189.2 kB / 1.523 GB, free: 15.39 MB / 1.232 GB Notification: Performance of preOpt removeEqualRHS (simulation): time 0.01882/1.533, allocations: 6.25 MB / 1.529 GB, free: 9.121 MB / 1.232 GB Warning: The model contains alias variables with redundant start and/or conflicting nominal values. It is recommended to resolve the conflicts, because otherwise the system could be hard to solve. To print the conflicting alias sets and the chosen candidates please use -d=aliasConflicts. Notification: Performance of preOpt removeSimpleEquations (simulation): time 0.5633/2.097, allocations: 35.24 MB / 1.564 GB, free: 399 MB / 1.232 GB Notification: Performance of preOpt comSubExp (simulation): time 0.01672/2.114, allocations: 5.224 MB / 1.569 GB, free: 397.4 MB / 1.232 GB Notification: Performance of preOpt resolveLoops (simulation): time 0.006784/2.12, allocations: 2.436 MB / 1.571 GB, free: 396.7 MB / 1.232 GB Notification: Performance of preOpt evalFunc (simulation): time 0.02735/2.148, allocations: 11.48 MB / 1.582 GB, free: 389.7 MB / 1.232 GB Notification: Performance of preOpt encapsulateWhenConditions (simulation): time 7.698e-05/2.148, allocations: 68.16 kB / 1.583 GB, free: 389.6 MB / 1.232 GB Notification: Performance of pre-optimization done (n=257): time 5.781e-06/2.148, allocations: 0 / 1.583 GB, free: 389.6 MB / 1.232 GB Notification: Performance of matching and sorting (n=257): time 0.0252/2.173, allocations: 7.805 MB / 1.59 GB, free: 387.5 MB / 1.232 GB Notification: Performance of inlineWhenForInitialization (initialization): time 4.345e-05/2.173, allocations: 77.41 kB / 1.59 GB, free: 387.5 MB / 1.232 GB Notification: Performance of selectInitializationVariablesDAE (initialization): time 0.04281/2.216, allocations: 16.17 MB / 1.606 GB, free: 381.8 MB / 1.232 GB Notification: Performance of collectPreVariables (initialization): time 0.001874/2.218, allocations: 109.2 kB / 1.606 GB, free: 381.8 MB / 1.232 GB Notification: Performance of collectInitialEqns (initialization): time 0.008705/2.227, allocations: 6.256 MB / 1.612 GB, free: 376.8 MB / 1.232 GB Notification: Performance of collectInitialBindings (initialization): time 0.001914/2.229, allocations: 0.9557 MB / 1.613 GB, free: 376 MB / 1.232 GB Notification: Performance of simplifyInitialFunctions (initialization): time 0.005834/2.234, allocations: 2.193 MB / 1.615 GB, free: 374.8 MB / 1.232 GB Notification: Performance of setup shared object (initialization): time 4.727e-05/2.234, allocations: 301.1 kB / 1.616 GB, free: 374.5 MB / 1.232 GB Notification: Performance of preBalanceInitialSystem (initialization): time 0.009655/2.244, allocations: 6.041 MB / 1.622 GB, free: 371.6 MB / 1.232 GB Notification: Performance of partitionIndependentBlocks (initialization): time 0.01168/2.256, allocations: 8.6 MB / 1.63 GB, free: 365.6 MB / 1.232 GB Notification: Performance of analyzeInitialSystem (initialization): time 0.01932/2.275, allocations: 13.49 MB / 1.643 GB, free: 357.6 MB / 1.232 GB Notification: Performance of solveInitialSystemEqSystem (initialization): time 0.0001014/2.275, allocations: 15.84 kB / 1.643 GB, free: 357.6 MB / 1.232 GB Notification: Performance of matching and sorting (n=1277) (initialization): time 0.03045/2.306, allocations: 15.94 MB / 1.659 GB, free: 344.4 MB / 1.232 GB Notification: Performance of prepare postOptimizeDAE: time 9.044e-05/2.306, allocations: 32 kB / 1.659 GB, free: 344.4 MB / 1.232 GB Notification: Performance of postOpt simplifyComplexFunction (initialization): time 0.0001126/2.306, allocations: 60 kB / 1.659 GB, free: 344.3 MB / 1.232 GB Notification: Performance of postOpt tearingSystem (initialization): time 0.00012/2.306, allocations: 100 kB / 1.659 GB, free: 344.2 MB / 1.232 GB Notification: Performance of postOpt solveSimpleEquations (initialization): time 0.008719/2.315, allocations: 1.975 MB / 1.661 GB, free: 342.2 MB / 1.232 GB Notification: Performance of postOpt calculateStrongComponentJacobians (initialization): time 0.0001765/2.315, allocations: 143.4 kB / 1.661 GB, free: 342.1 MB / 1.232 GB Notification: Performance of postOpt simplifyAllExpressions (initialization): time 0.01388/2.329, allocations: 1.187 MB / 1.662 GB, free: 340.9 MB / 1.232 GB Notification: Performance of postOpt collapseArrayExpressions (initialization): time 0.002188/2.331, allocations: 451.3 kB / 1.663 GB, free: 340.5 MB / 1.232 GB Notification: Performance of preBalanceInitialSystem (initialization_lambda0): time 0.01633/2.348, allocations: 8.447 MB / 1.671 GB, free: 332.1 MB / 1.232 GB Notification: Performance of partitionIndependentBlocks (initialization_lambda0): time 0.01107/2.359, allocations: 8.009 MB / 1.679 GB, free: 323.2 MB / 1.232 GB Notification: Performance of analyzeInitialSystem (initialization_lambda0): time 0.01697/2.376, allocations: 12.35 MB / 1.691 GB, free: 310 MB / 1.232 GB Notification: Performance of solveInitialSystemEqSystem (initialization_lambda0): time 6.035e-05/2.376, allocations: 20 kB / 1.691 GB, free: 310 MB / 1.232 GB Notification: Performance of matching and sorting (n=1277) (initialization_lambda0): time 0.02802/2.404, allocations: 14.75 MB / 1.705 GB, free: 295.2 MB / 1.232 GB Notification: Performance of prepare postOptimizeDAE: time 7.794e-05/2.404, allocations: 35.94 kB / 1.705 GB, free: 295.2 MB / 1.232 GB Notification: Performance of postOpt simplifyComplexFunction (initialization): time 0.0001055/2.404, allocations: 60 kB / 1.705 GB, free: 295.1 MB / 1.232 GB Notification: Performance of postOpt tearingSystem (initialization): time 9.846e-05/2.404, allocations: 100 kB / 1.705 GB, free: 295 MB / 1.232 GB Notification: Performance of postOpt solveSimpleEquations (initialization): time 0.008004/2.412, allocations: 1.908 MB / 1.707 GB, free: 293.1 MB / 1.232 GB Notification: Performance of postOpt calculateStrongComponentJacobians (initialization): time 0.0001721/2.412, allocations: 143.5 kB / 1.707 GB, free: 293 MB / 1.232 GB Notification: Performance of postOpt simplifyAllExpressions (initialization): time 0.01175/2.424, allocations: 0.9438 MB / 1.708 GB, free: 292 MB / 1.232 GB Notification: Performance of postOpt collapseArrayExpressions (initialization): time 0.00155/2.426, allocations: 417.6 kB / 1.709 GB, free: 291.6 MB / 1.232 GB Notification: Model statistics after passing the back-end for initialization: * Number of independent subsystems: 281 * Number of states: 0 () * Number of discrete variables: 0 () * Number of discrete states: 0 () * Number of clocked states: 0 () * Top-level inputs: 0 Notification: Strong component statistics for initialization (902): * Single equations (assignments): 882 * Array equations: 10 * Algorithm blocks: 0 * Record equations: 10 * When equations: 0 * If-equations: 0 * Equation systems (not torn): 0 * Torn equation systems: 0 * Mixed (continuous/discrete) equation systems: 0 Notification: Performance of prepare postOptimizeDAE: time 0.002614/2.428, allocations: 0.5761 MB / 1.709 GB, free: 291 MB / 1.232 GB Notification: Performance of postOpt lateInlineFunction (simulation): time 0.004128/2.433, allocations: 1.272 MB / 1.71 GB, free: 289.7 MB / 1.232 GB Notification: Performance of postOpt wrapFunctionCalls (simulation): time 0.01963/2.452, allocations: 6.96 MB / 1.717 GB, free: 282.8 MB / 1.232 GB Notification: Performance of postOpt inlineArrayEqn (simulation): time 6.15e-05/2.452, allocations: 39.98 kB / 1.717 GB, free: 282.7 MB / 1.232 GB Notification: Performance of postOpt constantLinearSystem (simulation): time 1.49e-05/2.452, allocations: 0 / 1.717 GB, free: 282.7 MB / 1.232 GB Notification: Performance of postOpt simplifysemiLinear (simulation): time 6.054e-05/2.452, allocations: 19.94 kB / 1.717 GB, free: 282.7 MB / 1.232 GB Notification: Performance of postOpt removeSimpleEquations (simulation): time 0.03936/2.492, allocations: 14.83 MB / 1.732 GB, free: 267.8 MB / 1.232 GB Notification: Performance of postOpt simplifyComplexFunction (simulation): time 1.431e-05/2.492, allocations: 0 / 1.732 GB, free: 267.8 MB / 1.232 GB Notification: Performance of postOpt solveSimpleEquations (simulation): time 0.005076/2.497, allocations: 0.8544 MB / 1.733 GB, free: 267 MB / 1.232 GB Notification: Performance of postOpt tearingSystem (simulation): time 4.034e-05/2.497, allocations: 12 kB / 1.733 GB, free: 267 MB / 1.232 GB Notification: Performance of postOpt inputDerivativesUsed (simulation): time 0.0006708/2.498, allocations: 119.9 kB / 1.733 GB, free: 266.8 MB / 1.232 GB Notification: Performance of postOpt calculateStrongComponentJacobians (simulation): time 2.424e-05/2.498, allocations: 12 kB / 1.733 GB, free: 266.8 MB / 1.232 GB Notification: Performance of postOpt calculateStateSetsJacobians (simulation): time 2.755e-06/2.498, allocations: 0 / 1.733 GB, free: 266.8 MB / 1.232 GB Notification: Performance of postOpt symbolicJacobian (simulation): time 0.02339/2.521, allocations: 9.543 MB / 1.742 GB, free: 257.2 MB / 1.232 GB Notification: Performance of postOpt removeConstants (simulation): time 0.007971/2.529, allocations: 2.13 MB / 1.744 GB, free: 255 MB / 1.232 GB Notification: Performance of postOpt simplifyTimeIndepFuncCalls (simulation): time 0.00466/2.534, allocations: 67.98 kB / 1.744 GB, free: 255 MB / 1.232 GB Notification: Performance of postOpt simplifyAllExpressions (simulation): time 0.00883/2.543, allocations: 427.6 kB / 1.745 GB, free: 254.5 MB / 1.232 GB Notification: Performance of postOpt findZeroCrossings (simulation): time 0.0005945/2.543, allocations: 194.1 kB / 1.745 GB, free: 254.3 MB / 1.232 GB Notification: Performance of postOpt collapseArrayExpressions (simulation): time 0.000826/2.544, allocations: 163.8 kB / 1.745 GB, free: 254.2 MB / 1.232 GB Notification: Performance of sorting global known variables: time 0.02175/2.566, allocations: 10.9 MB / 1.756 GB, free: 243.4 MB / 1.232 GB Notification: Performance of sort global known variables: time 4.61e-07/2.566, allocations: 0 / 1.756 GB, free: 243.4 MB / 1.232 GB Notification: Performance of remove unused functions: time 0.0187/2.585, allocations: 5.268 MB / 1.761 GB, free: 238.2 MB / 1.232 GB Notification: Model statistics after passing the back-end for simulation: * Number of independent subsystems: 5 * Number of states: 20 (pump1.filter.s[1],pump1.filter.s[2],pump2.filter.s[1],pump2.filter.s[2],pump3.filter.s[1],pump3.filter.s[2],pump4.filter.s[1],pump4.filter.s[2],pump5.filter.s[1],pump5.filter.s[2],forcedPump1.filter.s[1],forcedPump1.filter.s[2],forcedPump2.filter.s[1],forcedPump2.filter.s[2],forcedPump3.filter.s[1],forcedPump3.filter.s[2],forcedPump4.filter.s[1],forcedPump4.filter.s[2],forcedPump5.filter.s[1],forcedPump5.filter.s[2]) * Number of discrete variables: 0 () * Number of discrete states: 0 () * Number of clocked states: 0 () * Top-level inputs: 0 Notification: Strong component statistics for simulation (314): * Single equations (assignments): 292 * Array equations: 0 * Algorithm blocks: 0 * Record equations: 22 * When equations: 0 * If-equations: 0 * Equation systems (not torn): 0 * Torn equation systems: 0 * Mixed (continuous/discrete) equation systems: 0 Notification: Performance of Backend phase and start with SimCode phase: time 0.003126/2.588, allocations: 1.309 MB / 1.762 GB, free: 237 MB / 1.232 GB Notification: Performance of simCode: created initialization part: time 0.02923/2.617, allocations: 16.98 MB / 1.779 GB, free: 220 MB / 1.232 GB Notification: Performance of simCode: created event and clocks part: time 8.326e-06/2.617, allocations: 4 kB / 1.779 GB, free: 220 MB / 1.232 GB Notification: Performance of simCode: created simulation system equations: time 0.006939/2.624, allocations: 2.63 MB / 1.781 GB, free: 217.4 MB / 1.232 GB Notification: Performance of simCode: created of all other equations (e.g. parameter, nominal, assert, etc): time 0.03085/2.655, allocations: 6.956 MB / 1.788 GB, free: 210.7 MB / 1.232 GB Notification: Performance of simCode: created linear, non-linear and system jacobian parts: time 0.04731/2.702, allocations: 24.58 MB / 1.812 GB, free: 186 MB / 1.232 GB Notification: Performance of simCode: some other stuff during SimCode phase: time 0.008654/2.711, allocations: 6.752 MB / 1.819 GB, free: 179.2 MB / 1.232 GB Notification: Performance of simCode: alias equations: time 0.01503/2.726, allocations: 3.813 MB / 1.822 GB, free: 175.4 MB / 1.232 GB Notification: Performance of simCode: all other stuff during SimCode phase: time 0.003834/2.73, allocations: 1.03 MB / 1.823 GB, free: 174.4 MB / 1.232 GB Notification: Performance of SimCode: time 9.72e-07/2.73, allocations: 0 / 1.823 GB, free: 174.4 MB / 1.232 GB Notification: Performance of Templates: time 1.147/3.877, allocations: 252.2 MB / 2.07 GB, free: 390.2 MB / 1.248 GB make -j1 -f Buildings_latest_Buildings.Fluid.Movers.Validation.Pump_y_stratos.makefile (rm -f Buildings_latest_Buildings.Fluid.Movers.Validation.Pump_y_stratos.pipe ; mkfifo Buildings_latest_Buildings.Fluid.Movers.Validation.Pump_y_stratos.pipe ; head -c 1048576 < Buildings_latest_Buildings.Fluid.Movers.Validation.Pump_y_stratos.pipe >> ../files/Buildings_latest_Buildings.Fluid.Movers.Validation.Pump_y_stratos.sim & ./Buildings_latest_Buildings.Fluid.Movers.Validation.Pump_y_stratos -abortSlowSimulation -alarm=480 -s gbode -emit_protected -lv LOG_STATS > Buildings_latest_Buildings.Fluid.Movers.Validation.Pump_y_stratos.pipe 2>&1) diffSimulationResults("Buildings_latest_Buildings.Fluid.Movers.Validation.Pump_y_stratos_res.mat","/mnt/ReferenceFiles/Buildings/csv/master/Buildings_Fluid_Movers_Validation_Pump_y_stratos.csv","/var/lib/jenkins1/ws/OpenModelicaLibraryTestingWork/OpenModelicaLibraryTesting/files/Buildings_latest_Buildings.Fluid.Movers.Validation.Pump_y_stratos.diff",relTol=0.003,relTolDiffMinMax=0.003,rangeDelta=0.001) Reference file matches