Running: ./testmodel.py --libraries=/home/hudson/saved_omc/libraries/.openmodelica/libraries --ompython_omhome=/usr Buildings_9_Buildings.Fluid.HeatExchangers.Validation.WetCoilEffectivenessNTU.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 9.1.2-maint.9.1.x/package.mo", uses=false) Using package Buildings with version 9.1.2 (/home/hudson/saved_omc/libraries/.openmodelica/libraries/Buildings 9.1.2-maint.9.1.x/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.HeatExchangers.Validation.WetCoilEffectivenessNTU,tolerance=1e-06,outputFormat="mat",numberOfIntervals=5000,variableFilter="time|hexWetNTU.Q1_flow|hexWetNTU_TX.Q1_flow|hexWetNTU.sta_b2.T|hexWetNTU_TX.sta_b2.T|relHumOut_eps.phi|hexWetNTU.SHR|hexWetNTU.dryFra|hexWetNTU.UA_nominal|hexWetNTU_TX.UA_nominal",fileNamePrefix="Buildings_9_Buildings.Fluid.HeatExchangers.Validation.WetCoilEffectivenessNTU") translateModel(Buildings.Fluid.HeatExchangers.Validation.WetCoilEffectivenessNTU,tolerance=1e-06,outputFormat="mat",numberOfIntervals=5000,variableFilter="time|hexWetNTU.Q1_flow|hexWetNTU_TX.Q1_flow|hexWetNTU.sta_b2.T|hexWetNTU_TX.sta_b2.T|relHumOut_eps.phi|hexWetNTU.SHR|hexWetNTU.dryFra|hexWetNTU.UA_nominal|hexWetNTU_TX.UA_nominal",fileNamePrefix="Buildings_9_Buildings.Fluid.HeatExchangers.Validation.WetCoilEffectivenessNTU") Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/ModelicaServices 4.0.0+maint.om/package.mo): time 0.001571/0.001571, allocations: 109.1 kB / 16.37 MB, free: 6.477 MB / 14.72 MB Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Complex 4.0.0+maint.om/package.mo): time 0.001631/0.001632, allocations: 193.8 kB / 17.31 MB, free: 5.824 MB / 14.72 MB Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Modelica 4.0.0+maint.om/package.mo): time 1.431/1.431, allocations: 222.9 MB / 241 MB, free: 15.18 MB / 206.1 MB Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Buildings 9.1.2-maint.9.1.x/package.mo): time 2.243/2.243, allocations: 390.3 MB / 0.6655 GB, free: 0.6445 MB / 0.5294 GB Notification: Performance of FrontEnd - loaded program: time 0.001402/0.001403, allocations: 67.27 kB / 0.814 GB, free: 32.65 MB / 0.6231 GB Notification: Performance of FrontEnd - Absyn->SCode: time 0.2519/0.2533, allocations: 140.4 MB / 0.9511 GB, free: 8.105 MB / 0.7325 GB Notification: Performance of NFInst.instantiate(Buildings.Fluid.HeatExchangers.Validation.WetCoilEffectivenessNTU): time 1.005/1.258, allocations: 369.8 MB / 1.312 GB, free: 15 MB / 0.9825 GB Notification: Performance of NFInst.instExpressions: time 0.05214/1.311, allocations: 33.32 MB / 1.345 GB, free: 13.59 MB / 1.014 GB Notification: Performance of NFInst.updateImplicitVariability: time 0.008855/1.319, allocations: 147.2 kB / 1.345 GB, free: 13.45 MB / 1.014 GB Notification: Performance of NFTyping.typeComponents: time 0.007984/1.327, allocations: 2.356 MB / 1.347 GB, free: 11.07 MB / 1.014 GB Notification: Performance of NFTyping.typeBindings: time 0.02394/1.351, allocations: 7.505 MB / 1.355 GB, free: 3.539 MB / 1.014 GB Notification: Performance of NFTyping.typeClassSections: time 0.01452/1.366, allocations: 4.542 MB / 1.359 GB, free: 15.04 MB / 1.029 GB Notification: Performance of NFFlatten.flatten: time 0.01857/1.385, allocations: 11.06 MB / 1.37 GB, free: 3.949 MB / 1.029 GB Notification: Performance of NFFlatten.resolveConnections: time 0.007302/1.392, allocations: 3.969 MB / 1.374 GB, free: 15.91 MB / 1.045 GB Notification: Performance of NFEvalConstants.evaluate: time 0.01696/1.409, allocations: 5.442 MB / 1.379 GB, free: 10.52 MB / 1.045 GB Notification: Performance of NFSimplifyModel.simplify: time 0.008108/1.417, allocations: 3.448 MB / 1.382 GB, free: 7.066 MB / 1.045 GB Notification: Performance of NFPackage.collectConstants: time 0.001886/1.419, allocations: 0.5469 MB / 1.383 GB, free: 6.52 MB / 1.045 GB Notification: Performance of NFFlatten.collectFunctions: time 0.01576/1.435, allocations: 6.799 MB / 1.389 GB, free: 15.71 MB / 1.061 GB Notification: Performance of NFScalarize.scalarize: time 0.00288/1.438, allocations: 1.464 MB / 1.391 GB, free: 14.24 MB / 1.061 GB Notification: Performance of NFVerifyModel.verify: time 0.006215/1.444, allocations: 2.839 MB / 1.394 GB, free: 11.39 MB / 1.061 GB Notification: Performance of NFConvertDAE.convert: time 0.02257/1.467, allocations: 9.754 MB / 1.403 GB, free: 1.605 MB / 1.061 GB Notification: Performance of FrontEnd - DAE generated: time 6.412e-06/1.467, allocations: 0 / 1.403 GB, free: 1.605 MB / 1.061 GB Notification: Performance of FrontEnd: time 1.823e-06/1.467, allocations: 0 / 1.403 GB, free: 1.605 MB / 1.061 GB Notification: Performance of Transformations before backend: time 0.0003093/1.467, allocations: 0 / 1.403 GB, free: 1.605 MB / 1.061 GB Notification: Model statistics after passing the front-end and creating the data structures used by the back-end: * Number of equations: 851 * Number of variables: 851 Notification: Performance of Generate backend data structure: time 0.01815/1.485, allocations: 5.935 MB / 1.409 GB, free: 11.57 MB / 1.076 GB Notification: Performance of prepare preOptimizeDAE: time 4.393e-05/1.485, allocations: 8.031 kB / 1.409 GB, free: 11.56 MB / 1.076 GB Notification: Performance of preOpt normalInlineFunction (simulation): time 0.03152/1.517, allocations: 4.294 MB / 1.413 GB, free: 7.254 MB / 1.076 GB Notification: Performance of preOpt evaluateParameters (simulation): time 0.01088/1.528, allocations: 3.693 MB / 1.417 GB, free: 3.496 MB / 1.076 GB Notification: Performance of preOpt simplifyIfEquations (simulation): time 0.0004663/1.528, allocations: 309 kB / 1.417 GB, free: 3.188 MB / 1.076 GB Notification: Performance of preOpt expandDerOperator (simulation): time 0.001696/1.53, allocations: 355.9 kB / 1.417 GB, free: 2.84 MB / 1.076 GB Notification: Performance of preOpt clockPartitioning (simulation): time 0.01761/1.547, allocations: 5.701 MB / 1.423 GB, free: 13.05 MB / 1.092 GB Notification: Performance of preOpt findStateOrder (simulation): time 7.354e-05/1.548, allocations: 0 / 1.423 GB, free: 13.05 MB / 1.092 GB Notification: Performance of preOpt replaceEdgeChange (simulation): time 0.0004997/1.548, allocations: 132 kB / 1.423 GB, free: 12.93 MB / 1.092 GB Notification: Performance of preOpt inlineArrayEqn (simulation): time 0.0001305/1.548, allocations: 134.5 kB / 1.423 GB, free: 12.79 MB / 1.092 GB Notification: Performance of preOpt removeEqualRHS (simulation): time 0.02261/1.571, allocations: 6.814 MB / 1.43 GB, free: 5.969 MB / 1.092 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 0.0497/1.621, allocations: 22.13 MB / 1.452 GB, free: 14.7 MB / 1.123 GB Notification: Performance of preOpt comSubExp (simulation): time 0.01229/1.633, allocations: 4.066 MB / 1.456 GB, free: 10.64 MB / 1.123 GB Notification: Performance of preOpt resolveLoops (simulation): time 0.007297/1.64, allocations: 2.27 MB / 1.458 GB, free: 8.367 MB / 1.123 GB Notification: Performance of preOpt evalFunc (simulation): time 0.01781/1.658, allocations: 8.168 MB / 1.466 GB, free: 15.82 MB / 1.139 GB Notification: Performance of preOpt encapsulateWhenConditions (simulation): time 0.007851/1.666, allocations: 2.408 MB / 1.468 GB, free: 13.4 MB / 1.139 GB Notification: Performance of pre-optimization done (n=230): time 1.067e-05/1.666, allocations: 3.984 kB / 1.468 GB, free: 13.39 MB / 1.139 GB Notification: Performance of matching and sorting (n=230): time 0.0357/1.702, allocations: 8.43 MB / 1.476 GB, free: 4.824 MB / 1.139 GB Notification: Performance of inlineWhenForInitialization (initialization): time 5.92e-05/1.702, allocations: 77.39 kB / 1.476 GB, free: 4.738 MB / 1.139 GB Notification: Performance of selectInitializationVariablesDAE (initialization): time 0.009254/1.711, allocations: 4.281 MB / 1.481 GB, free: 448 kB / 1.139 GB Notification: Performance of collectPreVariables (initialization): time 0.001007/1.712, allocations: 77.69 kB / 1.481 GB, free: 364 kB / 1.139 GB Notification: Performance of collectInitialEqns (initialization): time 0.002032/1.714, allocations: 1.825 MB / 1.482 GB, free: 14.51 MB / 1.154 GB Notification: Performance of collectInitialBindings (initialization): time 0.001471/1.716, allocations: 0.7895 MB / 1.483 GB, free: 13.71 MB / 1.154 GB Notification: Performance of simplifyInitialFunctions (initialization): time 0.002058/1.718, allocations: 0.808 MB / 1.484 GB, free: 12.89 MB / 1.154 GB Notification: Performance of setup shared object (initialization): time 0.0001114/1.718, allocations: 305.1 kB / 1.484 GB, free: 12.59 MB / 1.154 GB Notification: Performance of preBalanceInitialSystem (initialization): time 0.009233/1.727, allocations: 2.716 MB / 1.487 GB, free: 9.875 MB / 1.154 GB Notification: Performance of partitionIndependentBlocks (initialization): time 0.01119/1.738, allocations: 3.404 MB / 1.49 GB, free: 6.238 MB / 1.154 GB Notification: It was not possible to check the given initialization system for consistency symbolically, because the relevant equations are part of an algebraic loop. This is not supported yet. Notification: Performance of analyzeInitialSystem (initialization): time 0.02071/1.759, allocations: 5.943 MB / 1.496 GB, free: 56 kB / 1.154 GB Notification: Performance of solveInitialSystemEqSystem (initialization): time 4.557e-05/1.759, allocations: 4 kB / 1.496 GB, free: 52 kB / 1.154 GB Notification: Performance of matching and sorting (n=448) (initialization): time 0.03031/1.79, allocations: 7.555 MB / 1.503 GB, free: 8.426 MB / 1.17 GB Notification: Performance of prepare postOptimizeDAE: time 4.022e-05/1.79, allocations: 8 kB / 1.503 GB, free: 8.418 MB / 1.17 GB Notification: Performance of postOpt simplifyComplexFunction (initialization): time 3.325e-05/1.79, allocations: 16 kB / 1.503 GB, free: 8.402 MB / 1.17 GB Notification: Performance of postOpt tearingSystem (initialization): time 0.004382/1.794, allocations: 0.9719 MB / 1.504 GB, free: 7.402 MB / 1.17 GB Notification: Performance of postOpt solveSimpleEquations (initialization): time 0.01023/1.804, allocations: 1.408 MB / 1.506 GB, free: 5.992 MB / 1.17 GB Notification: Performance of postOpt calculateStrongComponentJacobians (initialization): time 0.01775/1.822, allocations: 14.45 MB / 1.52 GB, free: 6.445 MB / 1.186 GB Notification: Performance of postOpt simplifyAllExpressions (initialization): time 0.01116/1.833, allocations: 1.168 MB / 1.521 GB, free: 5.273 MB / 1.186 GB Notification: Performance of postOpt collapseArrayExpressions (initialization): time 0.001377/1.835, allocations: 187.8 kB / 1.521 GB, free: 5.09 MB / 1.186 GB Warning: The initial conditions are over specified. The following 2 initial equations are redundant, so they are removed from the initialization system: hexWetNTU.UAFroRated.TAirIn = 293.15 hexWetNTU.UAFroRated.TWatIn = 293.15. Notification: Model statistics after passing the back-end for initialization: * Number of independent subsystems: 67 * Number of states: 0 () * Number of discrete variables: 13 (hexWetNTU.UAFroRated.isFulWet,hexWetNTU.UAFroRated.isFulDry,hexWetNTU.flowRegime_nominal,hexWetNTU_TX.flowRegime_nominal,$PRE.w_a2.nextTimeEvent,$whenCondition1,hexWetNTU_TX.UAFroRated.isFulWet,hexWetNTU_TX.UAFroRated.isFulDry,w_a2.nextTimeEventScaled,$PRE.w_a2.nextTimeEventScaled,w_a2.nextTimeEvent,hexWetNTU_TX.flowRegime,hexWetNTU.flowRegime) * Number of discrete states: 0 () * Number of clocked states: 0 () * Top-level inputs: 0 Notification: Strong component statistics for initialization (418): * Single equations (assignments): 403 * Array equations: 4 * Algorithm blocks: 0 * Record equations: 0 * When equations: 0 * If-equations: 0 * Equation systems (not torn): 2 * Torn equation systems: 9 * Mixed (continuous/discrete) equation systems: 0 Notification: Equation system details (not torn): * Constant Jacobian (size): 0 systems * Linear Jacobian (size,density): 0 systems * Non-linear Jacobian (size): 2 systems {1, 1} * Without analytic Jacobian (size): 0 systems Notification: Torn system details for strict tearing set: * Linear torn systems (#iteration vars, #inner vars, density): 0 systems * Non-linear torn systems (#iteration vars, #inner vars): 9 systems {(1,1), (1,3), (1,2), (1,2), (1,4), (1,2), (1,4), (1,2), (5,2)} Notification: Performance of prepare postOptimizeDAE: time 0.003655/1.838, allocations: 0.8485 MB / 1.522 GB, free: 4.23 MB / 1.186 GB Notification: Performance of postOpt lateInlineFunction (simulation): time 0.002083/1.84, allocations: 430.6 kB / 1.522 GB, free: 3.805 MB / 1.186 GB Notification: Performance of postOpt wrapFunctionCalls (simulation): time 0.02166/1.862, allocations: 5.799 MB / 1.528 GB, free: 13.97 MB / 1.201 GB Notification: Performance of postOpt inlineArrayEqn (simulation): time 4.533e-05/1.862, allocations: 27.94 kB / 1.528 GB, free: 13.95 MB / 1.201 GB Notification: Performance of postOpt constantLinearSystem (simulation): time 8.506e-06/1.862, allocations: 0 / 1.528 GB, free: 13.95 MB / 1.201 GB Notification: Performance of postOpt simplifysemiLinear (simulation): time 6.94e-05/1.862, allocations: 11.95 kB / 1.528 GB, free: 13.93 MB / 1.201 GB Notification: Performance of postOpt removeSimpleEquations (simulation): time 0.03577/1.898, allocations: 10.91 MB / 1.539 GB, free: 2.855 MB / 1.201 GB Notification: Performance of postOpt simplifyComplexFunction (simulation): time 2.815e-05/1.898, allocations: 7.984 kB / 1.539 GB, free: 2.848 MB / 1.201 GB Notification: Performance of postOpt solveSimpleEquations (simulation): time 0.005191/1.903, allocations: 0.6636 MB / 1.539 GB, free: 2.184 MB / 1.201 GB Notification: Performance of postOpt tearingSystem (simulation): time 0.003264/1.907, allocations: 0.7715 MB / 1.54 GB, free: 1.387 MB / 1.201 GB Notification: Performance of postOpt inputDerivativesUsed (simulation): time 0.0007649/1.907, allocations: 87.89 kB / 1.54 GB, free: 1.301 MB / 1.201 GB Notification: Performance of postOpt calculateStrongComponentJacobians (simulation): time 0.5817/2.489, allocations: 11.67 MB / 1.552 GB, free: 452.6 MB / 1.201 GB Notification: Performance of postOpt calculateStateSetsJacobians (simulation): time 7.644e-06/2.489, allocations: 8.625 kB / 1.552 GB, free: 452.6 MB / 1.201 GB Notification: Performance of postOpt symbolicJacobian (simulation): time 0.03299/2.522, allocations: 8.208 MB / 1.56 GB, free: 450 MB / 1.201 GB Notification: Performance of postOpt removeConstants (simulation): time 0.003537/2.526, allocations: 1.059 MB / 1.561 GB, free: 449.5 MB / 1.201 GB Notification: Performance of postOpt simplifyTimeIndepFuncCalls (simulation): time 0.001265/2.527, allocations: 46.92 kB / 1.561 GB, free: 449.5 MB / 1.201 GB Notification: Performance of postOpt simplifyAllExpressions (simulation): time 0.006736/2.534, allocations: 0.5229 MB / 1.561 GB, free: 449.5 MB / 1.201 GB Notification: Performance of postOpt findZeroCrossings (simulation): time 0.0006673/2.534, allocations: 168.1 kB / 1.561 GB, free: 449.4 MB / 1.201 GB Notification: Performance of postOpt collapseArrayExpressions (simulation): time 0.0004578/2.535, allocations: 113 kB / 1.562 GB, free: 449.4 MB / 1.201 GB Notification: Performance of sorting global known variables: time 0.00701/2.542, allocations: 2.944 MB / 1.564 GB, free: 448.4 MB / 1.201 GB Notification: Performance of sort global known variables: time 1.833e-06/2.542, allocations: 3.719 kB / 1.564 GB, free: 448.4 MB / 1.201 GB Notification: Performance of remove unused functions: time 0.007436/2.549, allocations: 1.541 MB / 1.566 GB, free: 448.3 MB / 1.201 GB Notification: Model statistics after passing the back-end for simulation: * Number of independent subsystems: 16 * Number of states: 8 (relHumIn.phi,TDryBulIn.T,senMasFraIn.X,senMasFraOut.X,TDryBulOut.T,hexWetNTU.dryWetCalcs.fullyWet.TWatOutEst,relHumOut_eps.phi,hexWetNTU_TX.dryWetCalcs.fullyWet.TWatOutEst) * Number of discrete variables: 5 ($whenCondition1,hexWetNTU.flowRegime,hexWetNTU_TX.flowRegime,w_a2.nextTimeEvent,w_a2.nextTimeEventScaled) * Number of discrete states: 2 (w_a2.nextTimeEvent,w_a2.nextTimeEventScaled) * Number of clocked states: 0 () * Top-level inputs: 0 Notification: Strong component statistics for simulation (227): * Single equations (assignments): 214 * Array equations: 0 * Algorithm blocks: 0 * Record equations: 3 * When equations: 2 * If-equations: 0 * Equation systems (not torn): 0 * Torn equation systems: 8 * Mixed (continuous/discrete) equation systems: 0 Notification: Torn system details for strict tearing set: * Linear torn systems (#iteration vars, #inner vars, density): 0 systems * Non-linear torn systems (#iteration vars, #inner vars): 8 systems {(1,4), (1,2), (1,4), (1,2), (1,1), (1,1), (1,3), (1,3)} Notification: Performance of Backend phase and start with SimCode phase: time 0.003133/2.553, allocations: 1.046 MB / 1.567 GB, free: 448.1 MB / 1.201 GB Notification: Performance of simCode: created initialization part: time 0.02431/2.577, allocations: 6.386 MB / 1.573 GB, free: 445.9 MB / 1.201 GB Notification: Performance of simCode: created event and clocks part: time 1.091e-05/2.577, allocations: 1.031 kB / 1.573 GB, free: 445.9 MB / 1.201 GB Notification: Performance of simCode: created simulation system equations: time 0.009637/2.587, allocations: 3.042 MB / 1.576 GB, free: 444.5 MB / 1.201 GB Notification: Performance of simCode: created of all other equations (e.g. parameter, nominal, assert, etc): time 0.01324/2.6, allocations: 2.094 MB / 1.578 GB, free: 443.9 MB / 1.201 GB Notification: Performance of simCode: created linear, non-linear and system jacobian parts: time 0.03124/2.631, allocations: 9.15 MB / 1.587 GB, free: 440.1 MB / 1.201 GB Notification: Performance of simCode: some other stuff during SimCode phase: time 0.002561/2.634, allocations: 2.298 MB / 1.589 GB, free: 439.2 MB / 1.201 GB Notification: Performance of simCode: alias equations: time 0.007221/2.641, allocations: 1.041 MB / 1.59 GB, free: 438.9 MB / 1.201 GB Notification: Performance of simCode: all other stuff during SimCode phase: time 0.002025/2.643, allocations: 370.3 kB / 1.591 GB, free: 438.9 MB / 1.201 GB Notification: Performance of SimCode: time 9.21e-07/2.643, allocations: 0 / 1.591 GB, free: 438.9 MB / 1.201 GB Notification: Performance of Templates: time 0.1312/2.774, allocations: 96.53 MB / 1.685 GB, free: 360.4 MB / 1.201 GB make -j1 -f Buildings_9_Buildings.Fluid.HeatExchangers.Validation.WetCoilEffectivenessNTU.makefile (rm -f Buildings_9_Buildings.Fluid.HeatExchangers.Validation.WetCoilEffectivenessNTU.pipe ; mkfifo Buildings_9_Buildings.Fluid.HeatExchangers.Validation.WetCoilEffectivenessNTU.pipe ; head -c 1048576 < Buildings_9_Buildings.Fluid.HeatExchangers.Validation.WetCoilEffectivenessNTU.pipe >> ../files/Buildings_9_Buildings.Fluid.HeatExchangers.Validation.WetCoilEffectivenessNTU.sim & ./Buildings_9_Buildings.Fluid.HeatExchangers.Validation.WetCoilEffectivenessNTU -abortSlowSimulation -alarm=480 -s cvode -emit_protected -lv LOG_STATS > Buildings_9_Buildings.Fluid.HeatExchangers.Validation.WetCoilEffectivenessNTU.pipe 2>&1) diffSimulationResults("Buildings_9_Buildings.Fluid.HeatExchangers.Validation.WetCoilEffectivenessNTU_res.mat","/mnt/ReferenceFiles/Buildings/csv/maint_9.1.x/Buildings_Fluid_HeatExchangers_Validation_WetCoilEffectivenessNTU.csv","/var/lib/jenkins1/ws/OpenModelicaLibraryTestingWork/OpenModelicaLibraryTesting/files/Buildings_9_Buildings.Fluid.HeatExchangers.Validation.WetCoilEffectivenessNTU.diff",relTol=0.003,relTolDiffMinMax=0.003,rangeDelta=0.001) Reference file matches