Running: ./testmodel.py --libraries=/home/hudson/saved_omc/libraries/.openmodelica/libraries --ompython_omhome=/usr Buildings_latest_Buildings.Fluid.FixedResistances.Examples.HydraulicDiameter.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.FixedResistances.Examples.HydraulicDiameter,tolerance=1e-06,outputFormat="mat",numberOfIntervals=5000,variableFilter="time|res.m_flow_nominal|res.m_flow|res.m_flow_turbulent|resLarPip.m_flow_nominal|resLarPip.m_flow|resLarPip.m_flow_turbulent|res.v|resLarPip.v|res.dh|resLarPip.dh",fileNamePrefix="Buildings_latest_Buildings.Fluid.FixedResistances.Examples.HydraulicDiameter") translateModel(Buildings.Fluid.FixedResistances.Examples.HydraulicDiameter,tolerance=1e-06,outputFormat="mat",numberOfIntervals=5000,variableFilter="time|res.m_flow_nominal|res.m_flow|res.m_flow_turbulent|resLarPip.m_flow_nominal|resLarPip.m_flow|resLarPip.m_flow_turbulent|res.v|resLarPip.v|res.dh|resLarPip.dh",fileNamePrefix="Buildings_latest_Buildings.Fluid.FixedResistances.Examples.HydraulicDiameter") Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/ModelicaServices 4.0.0+maint.om/package.mo): time 0.001457/0.001457, allocations: 104.2 kB / 16.35 MB, free: 5.875 MB / 14.72 MB Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Complex 4.0.0+maint.om/package.mo): time 0.001595/0.001596, allocations: 191 kB / 17.29 MB, free: 5.516 MB / 14.72 MB Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Modelica 4.0.0+maint.om/package.mo): time 1.457/1.457, allocations: 222.9 MB / 241 MB, free: 15 MB / 206.1 MB Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Buildings 11.0.0-master/package.mo): time 2.601/2.601, allocations: 442.6 MB / 0.7165 GB, free: 14.63 MB / 0.5919 GB Notification: Performance of FrontEnd - loaded program: time 0.001493/0.001493, allocations: 68.84 kB / 0.8773 GB, free: 10.97 MB / 0.6544 GB Notification: Performance of FrontEnd - Absyn->SCode: time 0.3424/0.3439, allocations: 153 MB / 1.027 GB, free: 2.051 MB / 0.795 GB Notification: Performance of NFInst.instantiate(Buildings.Fluid.FixedResistances.Examples.HydraulicDiameter): time 0.02064/0.3646, allocations: 15.06 MB / 1.041 GB, free: 2.938 MB / 0.8106 GB Notification: Performance of NFInst.instExpressions: time 0.006919/0.3716, allocations: 3.898 MB / 1.045 GB, free: 15.03 MB / 0.8262 GB Notification: Performance of NFInst.updateImplicitVariability: time 0.0009724/0.3726, allocations: 23.94 kB / 1.045 GB, free: 15.01 MB / 0.8262 GB Notification: Performance of NFTyping.typeComponents: time 0.000925/0.3736, allocations: 182.7 kB / 1.045 GB, free: 14.83 MB / 0.8262 GB Notification: Performance of NFTyping.typeBindings: time 0.002438/0.3761, allocations: 0.6763 MB / 1.046 GB, free: 14.15 MB / 0.8262 GB Notification: Performance of NFTyping.typeClassSections: time 0.001539/0.3777, allocations: 485.6 kB / 1.047 GB, free: 13.68 MB / 0.8262 GB Notification: Performance of NFFlatten.flatten: time 0.001899/0.3796, allocations: 1.076 MB / 1.048 GB, free: 12.6 MB / 0.8262 GB Notification: Performance of NFFlatten.resolveConnections: time 0.0006629/0.3802, allocations: 285.5 kB / 1.048 GB, free: 12.32 MB / 0.8262 GB Notification: Performance of NFEvalConstants.evaluate: time 0.0009184/0.3812, allocations: 410.4 kB / 1.048 GB, free: 11.91 MB / 0.8262 GB Notification: Performance of NFSimplifyModel.simplify: time 0.0005224/0.3817, allocations: 262.8 kB / 1.049 GB, free: 11.66 MB / 0.8262 GB Notification: Performance of NFPackage.collectConstants: time 8.506e-05/0.3818, allocations: 24 kB / 1.049 GB, free: 11.63 MB / 0.8262 GB Notification: Performance of NFFlatten.collectFunctions: time 0.001584/0.3834, allocations: 0.7173 MB / 1.049 GB, free: 10.91 MB / 0.8262 GB Notification: Performance of NFScalarize.scalarize: time 0.000158/0.3836, allocations: 75.67 kB / 1.049 GB, free: 10.84 MB / 0.8262 GB Notification: Performance of NFVerifyModel.verify: time 0.0003804/0.384, allocations: 179 kB / 1.049 GB, free: 10.66 MB / 0.8262 GB Notification: Performance of NFConvertDAE.convert: time 0.001554/0.3855, allocations: 0.7284 MB / 1.05 GB, free: 9.934 MB / 0.8262 GB Notification: Performance of FrontEnd - DAE generated: time 5.53e-06/0.3856, allocations: 3.938 kB / 1.05 GB, free: 9.93 MB / 0.8262 GB Notification: Performance of FrontEnd: time 1.693e-06/0.3856, allocations: 0 / 1.05 GB, free: 9.93 MB / 0.8262 GB Notification: Performance of Transformations before backend: time 2.157e-05/0.3856, allocations: 0 / 1.05 GB, free: 9.93 MB / 0.8262 GB Notification: Model statistics after passing the front-end and creating the data structures used by the back-end: * Number of equations: 40 * Number of variables: 40 Notification: Performance of Generate backend data structure: time 0.001504/0.3871, allocations: 0.7357 MB / 1.051 GB, free: 9.141 MB / 0.8262 GB Notification: Performance of prepare preOptimizeDAE: time 4.309e-05/0.3872, allocations: 8.031 kB / 1.051 GB, free: 9.133 MB / 0.8262 GB Notification: Performance of preOpt normalInlineFunction (simulation): time 0.0001365/0.3873, allocations: 44.47 kB / 1.051 GB, free: 9.09 MB / 0.8262 GB Notification: Performance of preOpt evaluateParameters (simulation): time 0.001245/0.3886, allocations: 0.5173 MB / 1.051 GB, free: 8.531 MB / 0.8262 GB Notification: Performance of preOpt simplifyIfEquations (simulation): time 2.173e-05/0.3886, allocations: 12.33 kB / 1.051 GB, free: 8.52 MB / 0.8262 GB Notification: Performance of preOpt expandDerOperator (simulation): time 3.314e-05/0.3886, allocations: 20 kB / 1.051 GB, free: 8.5 MB / 0.8262 GB Notification: Performance of preOpt clockPartitioning (simulation): time 0.0003883/0.389, allocations: 180.1 kB / 1.052 GB, free: 8.32 MB / 0.8262 GB Notification: Performance of preOpt findStateOrder (simulation): time 1.012e-05/0.389, allocations: 4 kB / 1.052 GB, free: 8.316 MB / 0.8262 GB Notification: Performance of preOpt replaceEdgeChange (simulation): time 2.124e-05/0.3891, allocations: 4 kB / 1.052 GB, free: 8.312 MB / 0.8262 GB Notification: Performance of preOpt inlineArrayEqn (simulation): time 7.484e-06/0.3891, allocations: 7.938 kB / 1.052 GB, free: 8.305 MB / 0.8262 GB Notification: Performance of preOpt removeEqualRHS (simulation): time 0.0003125/0.3894, allocations: 140.2 kB / 1.052 GB, free: 8.168 MB / 0.8262 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 0.001184/0.3906, allocations: 0.8605 MB / 1.053 GB, free: 7.207 MB / 0.8262 GB Notification: Performance of preOpt comSubExp (simulation): time 0.0002569/0.3909, allocations: 118.6 kB / 1.053 GB, free: 7.082 MB / 0.8262 GB Notification: Performance of preOpt resolveLoops (simulation): time 0.0001654/0.391, allocations: 80.75 kB / 1.053 GB, free: 7 MB / 0.8262 GB Notification: Performance of preOpt evalFunc (simulation): time 0.0003247/0.3914, allocations: 336.4 kB / 1.053 GB, free: 6.598 MB / 0.8262 GB Notification: Performance of preOpt encapsulateWhenConditions (simulation): time 3.994e-05/0.3914, allocations: 34.56 kB / 1.053 GB, free: 6.555 MB / 0.8262 GB Notification: Performance of pre-optimization done (n=12): time 1.462e-06/0.3914, allocations: 0 / 1.053 GB, free: 6.555 MB / 0.8262 GB Notification: Performance of matching and sorting (n=12): time 0.0005738/0.392, allocations: 217.1 kB / 1.053 GB, free: 6.336 MB / 0.8262 GB Notification: Performance of inlineWhenForInitialization (initialization): time 3.877e-05/0.3921, allocations: 59.39 kB / 1.053 GB, free: 6.266 MB / 0.8262 GB Notification: Performance of selectInitializationVariablesDAE (initialization): time 0.0003379/0.3924, allocations: 341.7 kB / 1.054 GB, free: 5.926 MB / 0.8262 GB Notification: Performance of collectPreVariables (initialization): time 3.401e-05/0.3924, allocations: 33.7 kB / 1.054 GB, free: 5.887 MB / 0.8262 GB Notification: Performance of collectInitialEqns (initialization): time 0.0001309/0.3926, allocations: 196.2 kB / 1.054 GB, free: 5.691 MB / 0.8262 GB Notification: Performance of collectInitialBindings (initialization): time 4.635e-05/0.3926, allocations: 39.45 kB / 1.054 GB, free: 5.652 MB / 0.8262 GB Notification: Performance of simplifyInitialFunctions (initialization): time 6.064e-05/0.3927, allocations: 33.7 kB / 1.054 GB, free: 5.613 MB / 0.8262 GB Notification: Performance of setup shared object (initialization): time 0.000135/0.3928, allocations: 338.8 kB / 1.054 GB, free: 5.273 MB / 0.8262 GB Notification: Performance of preBalanceInitialSystem (initialization): time 0.0001334/0.393, allocations: 60.69 kB / 1.054 GB, free: 5.211 MB / 0.8262 GB Notification: Performance of partitionIndependentBlocks (initialization): time 0.0001714/0.3932, allocations: 88.25 kB / 1.055 GB, free: 5.109 MB / 0.8262 GB Notification: Performance of analyzeInitialSystem (initialization): time 0.0002527/0.3934, allocations: 113.7 kB / 1.055 GB, free: 4.992 MB / 0.8262 GB Notification: Performance of solveInitialSystemEqSystem (initialization): time 2.124e-06/0.3934, allocations: 0 / 1.055 GB, free: 4.992 MB / 0.8262 GB Notification: Performance of matching and sorting (n=12) (initialization): time 0.0003688/0.3938, allocations: 185 kB / 1.055 GB, free: 4.805 MB / 0.8262 GB Notification: Performance of prepare postOptimizeDAE: time 1.771e-05/0.3938, allocations: 7.938 kB / 1.055 GB, free: 4.797 MB / 0.8262 GB Notification: Performance of postOpt simplifyComplexFunction (initialization): time 5.751e-06/0.3938, allocations: 4 kB / 1.055 GB, free: 4.793 MB / 0.8262 GB Notification: Performance of postOpt tearingSystem (initialization): time 1.621e-05/0.3939, allocations: 4.031 kB / 1.055 GB, free: 4.789 MB / 0.8262 GB Notification: Performance of postOpt solveSimpleEquations (initialization): time 0.0001452/0.394, allocations: 23.98 kB / 1.055 GB, free: 4.766 MB / 0.8262 GB Notification: Performance of postOpt calculateStrongComponentJacobians (initialization): time 8.376e-06/0.394, allocations: 4 kB / 1.055 GB, free: 4.762 MB / 0.8262 GB Notification: Performance of postOpt simplifyAllExpressions (initialization): time 0.0001854/0.3942, allocations: 23.91 kB / 1.055 GB, free: 4.738 MB / 0.8262 GB Notification: Performance of postOpt collapseArrayExpressions (initialization): time 2.415e-05/0.3943, allocations: 4 kB / 1.055 GB, free: 4.734 MB / 0.8262 GB Notification: Performance of preBalanceInitialSystem (initialization_lambda0): time 0.0002095/0.3945, allocations: 152.1 kB / 1.055 GB, free: 4.582 MB / 0.8262 GB Notification: Performance of partitionIndependentBlocks (initialization_lambda0): time 0.0001502/0.3946, allocations: 92.19 kB / 1.055 GB, free: 4.477 MB / 0.8262 GB Notification: Performance of analyzeInitialSystem (initialization_lambda0): time 0.0002197/0.3949, allocations: 109.6 kB / 1.055 GB, free: 4.363 MB / 0.8262 GB Notification: Performance of solveInitialSystemEqSystem (initialization_lambda0): time 9.21e-07/0.3949, allocations: 4 kB / 1.055 GB, free: 4.359 MB / 0.8262 GB Notification: Performance of matching and sorting (n=12) (initialization_lambda0): time 0.0003284/0.3952, allocations: 177.2 kB / 1.055 GB, free: 4.18 MB / 0.8262 GB Notification: Performance of prepare postOptimizeDAE: time 6.402e-06/0.3952, allocations: 8 kB / 1.055 GB, free: 4.172 MB / 0.8262 GB Notification: Performance of postOpt simplifyComplexFunction (initialization): time 2.996e-06/0.3952, allocations: 4 kB / 1.055 GB, free: 4.168 MB / 0.8262 GB Notification: Performance of postOpt tearingSystem (initialization): time 2.785e-06/0.3952, allocations: 3.938 kB / 1.055 GB, free: 4.164 MB / 0.8262 GB Notification: Performance of postOpt solveSimpleEquations (initialization): time 0.000104/0.3953, allocations: 27.92 kB / 1.055 GB, free: 4.137 MB / 0.8262 GB Notification: Performance of postOpt calculateStrongComponentJacobians (initialization): time 1.833e-06/0.3954, allocations: 0 / 1.055 GB, free: 4.137 MB / 0.8262 GB Notification: Performance of postOpt simplifyAllExpressions (initialization): time 0.0001639/0.3955, allocations: 15.89 kB / 1.055 GB, free: 4.121 MB / 0.8262 GB Notification: Performance of postOpt collapseArrayExpressions (initialization): time 1.513e-05/0.3955, allocations: 8 kB / 1.055 GB, free: 4.113 MB / 0.8262 GB Notification: Model statistics after passing the back-end for initialization: * Number of independent subsystems: 2 * 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 (12): * Single equations (assignments): 12 * Array equations: 0 * Algorithm blocks: 0 * Record equations: 0 * 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 0.0001172/0.3957, allocations: 192.2 kB / 1.056 GB, free: 3.918 MB / 0.8262 GB Notification: Performance of postOpt lateInlineFunction (simulation): time 6.014e-05/0.3957, allocations: 35.56 kB / 1.056 GB, free: 3.883 MB / 0.8262 GB Notification: Performance of postOpt wrapFunctionCalls (simulation): time 0.0005035/0.3962, allocations: 233.3 kB / 1.056 GB, free: 3.645 MB / 0.8262 GB Notification: Performance of postOpt inlineArrayEqn (simulation): time 7.565e-06/0.3963, allocations: 0 / 1.056 GB, free: 3.645 MB / 0.8262 GB Notification: Performance of postOpt constantLinearSystem (simulation): time 6.132e-06/0.3963, allocations: 0 / 1.056 GB, free: 3.645 MB / 0.8262 GB Notification: Performance of postOpt simplifysemiLinear (simulation): time 4.087e-06/0.3963, allocations: 0 / 1.056 GB, free: 3.645 MB / 0.8262 GB Notification: Performance of postOpt removeSimpleEquations (simulation): time 0.0008736/0.3972, allocations: 0.6256 MB / 1.057 GB, free: 2.953 MB / 0.8262 GB Notification: Performance of postOpt simplifyComplexFunction (simulation): time 4.338e-06/0.3972, allocations: 4 kB / 1.057 GB, free: 2.949 MB / 0.8262 GB Notification: Performance of postOpt solveSimpleEquations (simulation): time 0.0001046/0.3973, allocations: 27.92 kB / 1.057 GB, free: 2.922 MB / 0.8262 GB Notification: Performance of postOpt tearingSystem (simulation): time 2.364e-06/0.3973, allocations: 128 / 1.057 GB, free: 2.922 MB / 0.8262 GB Notification: Performance of postOpt inputDerivativesUsed (simulation): time 1.819e-05/0.3973, allocations: 11.98 kB / 1.057 GB, free: 2.91 MB / 0.8262 GB Notification: Performance of postOpt calculateStrongComponentJacobians (simulation): time 1.833e-06/0.3973, allocations: 0 / 1.057 GB, free: 2.91 MB / 0.8262 GB Notification: Performance of postOpt calculateStateSetsJacobians (simulation): time 1.072e-06/0.3973, allocations: 0 / 1.057 GB, free: 2.91 MB / 0.8262 GB Notification: Performance of postOpt symbolicJacobian (simulation): time 0.0004411/0.3978, allocations: 328.8 kB / 1.057 GB, free: 2.566 MB / 0.8262 GB Notification: Performance of postOpt removeConstants (simulation): time 0.0001173/0.3979, allocations: 124.6 kB / 1.057 GB, free: 2.426 MB / 0.8262 GB Notification: Performance of postOpt simplifyTimeIndepFuncCalls (simulation): time 4.208e-05/0.398, allocations: 8 kB / 1.057 GB, free: 2.418 MB / 0.8262 GB Notification: Performance of postOpt simplifyAllExpressions (simulation): time 0.0001975/0.3982, allocations: 15.98 kB / 1.057 GB, free: 2.402 MB / 0.8262 GB Notification: Performance of postOpt findZeroCrossings (simulation): time 4.529e-05/0.3982, allocations: 11.98 kB / 1.057 GB, free: 2.391 MB / 0.8262 GB Notification: Performance of postOpt collapseArrayExpressions (simulation): time 1.492e-05/0.3982, allocations: 7.984 kB / 1.057 GB, free: 2.383 MB / 0.8262 GB Notification: Performance of sorting global known variables: time 0.0002277/0.3985, allocations: 243.2 kB / 1.057 GB, free: 2.145 MB / 0.8262 GB Notification: Performance of sort global known variables: time 1.2e-07/0.3985, allocations: 4 kB / 1.057 GB, free: 2.141 MB / 0.8262 GB Notification: Performance of remove unused functions: time 0.0005821/0.3991, allocations: 195.5 kB / 1.057 GB, free: 1.949 MB / 0.8262 GB Notification: Model statistics after passing the back-end for simulation: * Number of independent subsystems: 4 * 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 simulation (14): * Single equations (assignments): 12 * Array equations: 0 * Algorithm blocks: 0 * Record equations: 2 * 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 0.0005263/0.3996, allocations: 250.4 kB / 1.058 GB, free: 1.703 MB / 0.8262 GB Notification: Performance of simCode: created initialization part: time 0.0004866/0.4001, allocations: 183.8 kB / 1.058 GB, free: 1.523 MB / 0.8262 GB Notification: Performance of simCode: created event and clocks part: time 2.715e-06/0.4001, allocations: 0 / 1.058 GB, free: 1.523 MB / 0.8262 GB Notification: Performance of simCode: created simulation system equations: time 0.0001695/0.4003, allocations: 80.02 kB / 1.058 GB, free: 1.445 MB / 0.8262 GB Notification: Performance of simCode: created of all other equations (e.g. parameter, nominal, assert, etc): time 0.0007777/0.4011, allocations: 150.5 kB / 1.058 GB, free: 1.301 MB / 0.8262 GB Notification: Performance of simCode: created linear, non-linear and system jacobian parts: time 0.0009088/0.402, allocations: 0.5594 MB / 1.059 GB, free: 0.707 MB / 0.8262 GB Notification: Performance of simCode: some other stuff during SimCode phase: time 0.0004012/0.4024, allocations: 0.7957 MB / 1.059 GB, free: 15.88 MB / 0.8419 GB Notification: Performance of simCode: alias equations: time 0.000213/0.4026, allocations: 83 kB / 1.059 GB, free: 15.8 MB / 0.8419 GB Notification: Performance of simCode: all other stuff during SimCode phase: time 5.636e-05/0.4027, allocations: 35.36 kB / 1.06 GB, free: 15.77 MB / 0.8419 GB Notification: Performance of SimCode: time 2.21e-07/0.4027, allocations: 0 / 1.06 GB, free: 15.77 MB / 0.8419 GB Notification: Performance of Templates: time 0.0118/0.4145, allocations: 6.562 MB / 1.066 GB, free: 9.305 MB / 0.8419 GB make -j1 -f Buildings_latest_Buildings.Fluid.FixedResistances.Examples.HydraulicDiameter.makefile (rm -f Buildings_latest_Buildings.Fluid.FixedResistances.Examples.HydraulicDiameter.pipe ; mkfifo Buildings_latest_Buildings.Fluid.FixedResistances.Examples.HydraulicDiameter.pipe ; head -c 1048576 < Buildings_latest_Buildings.Fluid.FixedResistances.Examples.HydraulicDiameter.pipe >> ../files/Buildings_latest_Buildings.Fluid.FixedResistances.Examples.HydraulicDiameter.sim & ./Buildings_latest_Buildings.Fluid.FixedResistances.Examples.HydraulicDiameter -abortSlowSimulation -alarm=480 -s gbode -emit_protected -lv LOG_STATS > Buildings_latest_Buildings.Fluid.FixedResistances.Examples.HydraulicDiameter.pipe 2>&1) diffSimulationResults("Buildings_latest_Buildings.Fluid.FixedResistances.Examples.HydraulicDiameter_res.mat","/mnt/ReferenceFiles/Buildings/csv/master/Buildings_Fluid_FixedResistances_Examples_HydraulicDiameter.csv","/var/lib/jenkins1/ws/OpenModelicaLibraryTestingWork/OpenModelicaLibraryTesting/files/Buildings_latest_Buildings.Fluid.FixedResistances.Examples.HydraulicDiameter.diff",relTol=0.003,relTolDiffMinMax=0.003,rangeDelta=0.001) Reference file matches