Running: ./testmodel.py --libraries=/home/hudson/saved_omc/libraries/.openmodelica/libraries --ompython_omhome=/usr Buildings_10_Buildings.Fluid.MixingVolumes.Validation.MixingVolumeInitialization.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 10.1.1-maint.10.0.x/package.mo", uses=false)
Using package Buildings with version 10.1.1 (/home/hudson/saved_omc/libraries/.openmodelica/libraries/Buildings 10.1.1-maint.10.0.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.MixingVolumes.Validation.MixingVolumeInitialization,tolerance=1e-06,outputFormat="mat",numberOfIntervals=5000,variableFilter="time|vol1.T_start|vol1.T|vol1.ports.1..h_outflow|vol1.ports.2..h_outflow|pipe1.port_b.h_outflow",fileNamePrefix="Buildings_10_Buildings.Fluid.MixingVolumes.Validation.MixingVolumeInitialization")
translateModel(Buildings.Fluid.MixingVolumes.Validation.MixingVolumeInitialization,tolerance=1e-06,outputFormat="mat",numberOfIntervals=5000,variableFilter="time|vol1.T_start|vol1.T|vol1.ports.1..h_outflow|vol1.ports.2..h_outflow|pipe1.port_b.h_outflow",fileNamePrefix="Buildings_10_Buildings.Fluid.MixingVolumes.Validation.MixingVolumeInitialization")
Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/ModelicaServices 4.0.0+maint.om/package.mo): time 0.006558/0.006558, allocations: 99.45 kB / 15.73 MB, free: 6.059 MB / 14.72 MB
Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Complex 4.0.0+maint.om/package.mo): time 0.001532/0.001532, allocations: 192.2 kB / 16.67 MB, free: 5.969 MB / 14.72 MB
Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Modelica 4.0.0+maint.om/package.mo): time 1.364/1.364, allocations: 222.9 MB / 240.4 MB, free: 15.15 MB / 206.1 MB
Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Buildings 10.1.1-maint.10.0.x/package.mo): time 2.49/2.49, allocations: 437 MB / 0.7105 GB, free: 4.41 MB / 0.5762 GB
Notification: Performance of FrontEnd - loaded program: time 0.001445/0.001445, allocations: 60.12 kB / 1.019 GB, free: 9.402 MB / 0.795 GB
Notification: Performance of FrontEnd - Absyn->SCode: time 0.8631/0.8645, allocations: 151.6 MB / 1.167 GB, free: 3.855 MB / 0.8887 GB
Notification: Performance of NFInst.instantiate(Buildings.Fluid.MixingVolumes.Validation.MixingVolumeInitialization): time 0.2056/1.07, allocations: 187.9 MB / 1.35 GB, free: 7.273 MB / 1.076 GB
Notification: Performance of NFInst.instExpressions: time 0.01559/1.086, allocations: 10.75 MB / 1.361 GB, free: 12.49 MB / 1.092 GB
Notification: Performance of NFInst.updateImplicitVariability: time 0.001313/1.087, allocations: 39.75 kB / 1.361 GB, free: 12.45 MB / 1.092 GB
Notification: Performance of NFTyping.typeComponents: time 0.001478/1.089, allocations: 0.4971 MB / 1.361 GB, free: 11.95 MB / 1.092 GB
Notification: Performance of NFTyping.typeBindings: time 0.007398/1.096, allocations: 2.667 MB / 1.364 GB, free: 9.273 MB / 1.092 GB
Notification: Performance of NFTyping.typeClassSections: time 0.006274/1.102, allocations: 2.474 MB / 1.366 GB, free: 6.805 MB / 1.092 GB
Notification: Performance of NFFlatten.flatten: time 0.004038/1.107, allocations: 2.779 MB / 1.369 GB, free: 4.016 MB / 1.092 GB
Notification: Performance of NFFlatten.resolveConnections: time 0.001338/1.108, allocations: 0.7838 MB / 1.37 GB, free: 3.215 MB / 1.092 GB
Notification: Performance of NFEvalConstants.evaluate: time 0.002059/1.11, allocations: 1.028 MB / 1.371 GB, free: 2.184 MB / 1.092 GB
Notification: Performance of NFSimplifyModel.simplify: time 0.002227/1.112, allocations: 1.061 MB / 1.372 GB, free: 1.125 MB / 1.092 GB
Notification: Performance of NFPackage.collectConstants: time 0.0002124/1.112, allocations: 96 kB / 1.372 GB, free: 1.031 MB / 1.092 GB
Notification: Performance of NFFlatten.collectFunctions: time 0.006044/1.118, allocations: 3.017 MB / 1.375 GB, free: 14.01 MB / 1.107 GB
Notification: Performance of NFScalarize.scalarize: time 0.0007062/1.119, allocations: 434.8 kB / 1.375 GB, free: 13.58 MB / 1.107 GB
Notification: Performance of NFVerifyModel.verify: time 0.0009805/1.12, allocations: 0.5794 MB / 1.376 GB, free: 13 MB / 1.107 GB
Notification: Performance of NFConvertDAE.convert: time 0.006506/1.127, allocations: 2.967 MB / 1.379 GB, free: 10.02 MB / 1.107 GB
Notification: Performance of FrontEnd - DAE generated: time 8.306e-06/1.127, allocations: 4 kB / 1.379 GB, free: 10.02 MB / 1.107 GB
Notification: Performance of FrontEnd: time 2.254e-06/1.127, allocations: 0 / 1.379 GB, free: 10.02 MB / 1.107 GB
Notification: Performance of Transformations before backend: time 2.123e-05/1.127, allocations: 0 / 1.379 GB, free: 10.02 MB / 1.107 GB
Notification: Model statistics after passing the front-end and creating the data structures used by the back-end:
 * Number of equations: 173
 * Number of variables: 173
Notification: Performance of Generate backend data structure: time 0.003779/1.131, allocations: 1.721 MB / 1.38 GB, free: 8.242 MB / 1.107 GB
Notification: Performance of prepare preOptimizeDAE: time 4.482e-05/1.131, allocations: 11.98 kB / 1.38 GB, free: 8.23 MB / 1.107 GB
Notification: Performance of preOpt normalInlineFunction (simulation): time 0.001799/1.132, allocations: 299 kB / 1.381 GB, free: 7.938 MB / 1.107 GB
Notification: Performance of preOpt evaluateParameters (simulation): time 0.001531/1.134, allocations: 0.8397 MB / 1.381 GB, free: 7.055 MB / 1.107 GB
Notification: Performance of preOpt simplifyIfEquations (simulation): time 5.268e-05/1.134, allocations: 57.3 kB / 1.381 GB, free: 6.996 MB / 1.107 GB
Notification: Performance of preOpt expandDerOperator (simulation): time 0.0001247/1.134, allocations: 63.97 kB / 1.381 GB, free: 6.934 MB / 1.107 GB
Notification: Performance of preOpt clockPartitioning (simulation): time 0.001583/1.136, allocations: 0.9883 MB / 1.382 GB, free: 5.93 MB / 1.107 GB
Notification: Performance of preOpt findStateOrder (simulation): time 2.363e-05/1.136, allocations: 3.984 kB / 1.382 GB, free: 5.926 MB / 1.107 GB
Notification: Performance of preOpt replaceEdgeChange (simulation): time 8.074e-05/1.136, allocations: 35.92 kB / 1.382 GB, free: 5.891 MB / 1.107 GB
Notification: Performance of preOpt inlineArrayEqn (simulation): time 0.0001012/1.136, allocations: 73.89 kB / 1.383 GB, free: 5.816 MB / 1.107 GB
Notification: Performance of preOpt removeEqualRHS (simulation): time 0.0016/1.138, allocations: 1.007 MB / 1.384 GB, free: 4.812 MB / 1.107 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 0.006041/1.144, allocations: 3.584 MB / 1.387 GB, free: 0.9961 MB / 1.107 GB
Notification: Performance of preOpt comSubExp (simulation): time 0.001105/1.145, allocations: 0.6611 MB / 1.388 GB, free: 332 kB / 1.107 GB
Notification: Performance of preOpt resolveLoops (simulation): time 0.0005534/1.145, allocations: 382.3 kB / 1.388 GB, free: 15.95 MB / 1.123 GB
Notification: Performance of preOpt evalFunc (simulation): time 0.0002798/1.146, allocations: 194.8 kB / 1.388 GB, free: 15.72 MB / 1.123 GB
Notification: Performance of preOpt encapsulateWhenConditions (simulation): time 3.645e-05/1.146, allocations: 47.11 kB / 1.388 GB, free: 15.67 MB / 1.123 GB
Notification: Performance of pre-optimization done (n=62): time 2.525e-06/1.146, allocations: 3.938 kB / 1.388 GB, free: 15.66 MB / 1.123 GB
Notification: Performance of matching and sorting (n=62): time 0.002009/1.148, allocations: 1.026 MB / 1.389 GB, free: 14.64 MB / 1.123 GB
Notification: Performance of inlineWhenForInitialization (initialization): time 7.219e-05/1.148, allocations: 115.4 kB / 1.389 GB, free: 14.5 MB / 1.123 GB
Notification: Performance of selectInitializationVariablesDAE (initialization): time 0.001011/1.149, allocations: 0.7981 MB / 1.39 GB, free: 13.69 MB / 1.123 GB
Notification: Performance of collectPreVariables (initialization): time 5.855e-05/1.149, allocations: 33.7 kB / 1.39 GB, free: 13.65 MB / 1.123 GB
Notification: Performance of collectInitialEqns (initialization): time 0.0003279/1.149, allocations: 436.7 kB / 1.391 GB, free: 13.22 MB / 1.123 GB
Notification: Performance of collectInitialBindings (initialization): time 0.0002109/1.149, allocations: 230 kB / 1.391 GB, free: 13 MB / 1.123 GB
Notification: Performance of simplifyInitialFunctions (initialization): time 0.0002437/1.15, allocations: 138.6 kB / 1.391 GB, free: 12.86 MB / 1.123 GB
Notification: Performance of setup shared object (initialization): time 0.0001489/1.15, allocations: 337.9 kB / 1.391 GB, free: 12.52 MB / 1.123 GB
Notification: Performance of preBalanceInitialSystem (initialization): time 0.0005388/1.15, allocations: 344.7 kB / 1.392 GB, free: 12.18 MB / 1.123 GB
Notification: Performance of partitionIndependentBlocks (initialization): time 0.0006449/1.151, allocations: 464.6 kB / 1.392 GB, free: 11.69 MB / 1.123 GB
Notification: Performance of analyzeInitialSystem (initialization): time 0.001108/1.152, allocations: 0.7665 MB / 1.393 GB, free: 10.89 MB / 1.123 GB
Notification: Performance of solveInitialSystemEqSystem (initialization): time 3.476e-06/1.152, allocations: 4 kB / 1.393 GB, free: 10.89 MB / 1.123 GB
Notification: Performance of matching and sorting (n=88) (initialization): time 0.001508/1.154, allocations: 0.9416 MB / 1.394 GB, free: 9.938 MB / 1.123 GB
Notification: Performance of prepare postOptimizeDAE: time 2.99e-05/1.154, allocations: 4 kB / 1.394 GB, free: 9.934 MB / 1.123 GB
Notification: Performance of postOpt simplifyComplexFunction (initialization): time 1.01e-05/1.154, allocations: 4 kB / 1.394 GB, free: 9.93 MB / 1.123 GB
Notification: Performance of postOpt tearingSystem (initialization): time 1.934e-05/1.154, allocations: 4 kB / 1.394 GB, free: 9.926 MB / 1.123 GB
Notification: Performance of postOpt solveSimpleEquations (initialization): time 0.0006893/1.154, allocations: 147.8 kB / 1.394 GB, free: 9.781 MB / 1.123 GB
Notification: Performance of postOpt calculateStrongComponentJacobians (initialization): time 1.453e-05/1.155, allocations: 12.2 kB / 1.394 GB, free: 9.77 MB / 1.123 GB
Notification: Performance of postOpt simplifyAllExpressions (initialization): time 0.0007457/1.155, allocations: 91.38 kB / 1.394 GB, free: 9.68 MB / 1.123 GB
Notification: Performance of postOpt collapseArrayExpressions (initialization): time 6.55e-05/1.155, allocations: 24 kB / 1.394 GB, free: 9.656 MB / 1.123 GB
Notification: Performance of preBalanceInitialSystem (initialization_lambda0): time 0.0008223/1.156, allocations: 0.537 MB / 1.395 GB, free: 9.113 MB / 1.123 GB
Notification: Performance of partitionIndependentBlocks (initialization_lambda0): time 0.0005955/1.157, allocations: 450.5 kB / 1.395 GB, free: 8.633 MB / 1.123 GB
Notification: Performance of analyzeInitialSystem (initialization_lambda0): time 0.001038/1.158, allocations: 0.733 MB / 1.396 GB, free: 7.859 MB / 1.123 GB
Notification: Performance of solveInitialSystemEqSystem (initialization_lambda0): time 2.235e-06/1.158, allocations: 0 / 1.396 GB, free: 7.859 MB / 1.123 GB
Notification: Performance of matching and sorting (n=88) (initialization_lambda0): time 0.001374/1.159, allocations: 0.895 MB / 1.397 GB, free: 6.957 MB / 1.123 GB
Notification: Performance of prepare postOptimizeDAE: time 1.236e-05/1.159, allocations: 12 kB / 1.397 GB, free: 6.945 MB / 1.123 GB
Notification: Performance of postOpt simplifyComplexFunction (initialization): time 3.507e-06/1.159, allocations: 0 / 1.397 GB, free: 6.945 MB / 1.123 GB
Notification: Performance of postOpt tearingSystem (initialization): time 9.077e-06/1.159, allocations: 8 kB / 1.397 GB, free: 6.938 MB / 1.123 GB
Notification: Performance of postOpt solveSimpleEquations (initialization): time 0.0006417/1.16, allocations: 143.8 kB / 1.397 GB, free: 6.797 MB / 1.123 GB
Notification: Performance of postOpt calculateStrongComponentJacobians (initialization): time 9.678e-06/1.16, allocations: 7.938 kB / 1.397 GB, free: 6.789 MB / 1.123 GB
Notification: Performance of postOpt simplifyAllExpressions (initialization): time 0.0006938/1.161, allocations: 71.72 kB / 1.397 GB, free: 6.719 MB / 1.123 GB
Notification: Performance of postOpt collapseArrayExpressions (initialization): time 6.093e-05/1.161, allocations: 24 kB / 1.397 GB, free: 6.695 MB / 1.123 GB
Notification: Model statistics after passing the back-end for initialization:
 * Number of independent subsystems: 10
 * 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 (88):
 * Single equations (assignments): 88
 * 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 0.000233/1.161, allocations: 228 kB / 1.397 GB, free: 6.465 MB / 1.123 GB
Notification: Performance of postOpt lateInlineFunction (simulation): time 0.0001542/1.161, allocations: 99.39 kB / 1.397 GB, free: 6.367 MB / 1.123 GB
Notification: Performance of postOpt wrapFunctionCalls (simulation): time 0.001414/1.162, allocations: 0.8047 MB / 1.398 GB, free: 5.555 MB / 1.123 GB
Notification: Performance of postOpt inlineArrayEqn (simulation): time 8.516e-06/1.163, allocations: 8 kB / 1.398 GB, free: 5.547 MB / 1.123 GB
Notification: Performance of postOpt constantLinearSystem (simulation): time 5.49e-06/1.163, allocations: 0 / 1.398 GB, free: 5.547 MB / 1.123 GB
Notification: Performance of postOpt simplifysemiLinear (simulation): time 0.001007/1.164, allocations: 0.7361 MB / 1.399 GB, free: 4.781 MB / 1.123 GB
Notification: Performance of postOpt removeSimpleEquations (simulation): time 0.003205/1.167, allocations: 2.105 MB / 1.401 GB, free: 2.578 MB / 1.123 GB
Notification: Performance of postOpt simplifyComplexFunction (simulation): time 7.574e-06/1.167, allocations: 7.938 kB / 1.401 GB, free: 2.57 MB / 1.123 GB
Notification: Performance of postOpt solveSimpleEquations (simulation): time 0.0006369/1.167, allocations: 131.9 kB / 1.401 GB, free: 2.441 MB / 1.123 GB
Notification: Performance of postOpt tearingSystem (simulation): time 1.233e-05/1.167, allocations: 11.98 kB / 1.401 GB, free: 2.43 MB / 1.123 GB
Notification: Performance of postOpt inputDerivativesUsed (simulation): time 4.808e-05/1.167, allocations: 16 kB / 1.401 GB, free: 2.414 MB / 1.123 GB
Notification: Performance of postOpt calculateStrongComponentJacobians (simulation): time 9.217e-06/1.168, allocations: 8 kB / 1.401 GB, free: 2.406 MB / 1.123 GB
Notification: Performance of postOpt calculateStateSetsJacobians (simulation): time 6.121e-06/1.168, allocations: 7.938 kB / 1.401 GB, free: 2.398 MB / 1.123 GB
Notification: Performance of postOpt symbolicJacobian (simulation): time 0.001823/1.169, allocations: 1.364 MB / 1.402 GB, free: 0.9766 MB / 1.123 GB
Notification: Performance of postOpt removeConstants (simulation): time 0.0004613/1.17, allocations: 264.3 kB / 1.402 GB, free: 0.6992 MB / 1.123 GB
Notification: Performance of postOpt simplifyTimeIndepFuncCalls (simulation): time 0.0001129/1.17, allocations: 16 kB / 1.402 GB, free: 0.6836 MB / 1.123 GB
Notification: Performance of postOpt simplifyAllExpressions (simulation): time 0.0005231/1.17, allocations: 23.98 kB / 1.402 GB, free: 0.6602 MB / 1.123 GB
Notification: Performance of postOpt findZeroCrossings (simulation): time 7.853e-05/1.171, allocations: 48.27 kB / 1.403 GB, free: 0.6094 MB / 1.123 GB
Notification: Performance of postOpt collapseArrayExpressions (simulation): time 4.964e-05/1.171, allocations: 27.98 kB / 1.403 GB, free: 0.582 MB / 1.123 GB
Notification: Performance of sorting global known variables: time 0.0006952/1.171, allocations: 0.5575 MB / 1.403 GB, free: 32 kB / 1.123 GB
Notification: Performance of sort global known variables: time 2.1e-07/1.171, allocations: 0 / 1.403 GB, free: 32 kB / 1.123 GB
Notification: Performance of remove unused functions: time 0.001682/1.173, allocations: 0.752 MB / 1.404 GB, free: 15.28 MB / 1.139 GB
Notification: Model statistics after passing the back-end for simulation:
 * Number of independent subsystems: 15
 * Number of states: 3 (vol1.dynBal.medium.Xi[1],vol1.dynBal.U,vol1.dynBal.m)
 * 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 (64):
 * Single equations (assignments): 64
 * 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 Backend phase and start with SimCode phase: time 0.001238/1.174, allocations: 0.5557 MB / 1.404 GB, free: 14.72 MB / 1.139 GB
Notification: Performance of simCode: created initialization part: time 0.001975/1.176, allocations: 1.182 MB / 1.406 GB, free: 13.55 MB / 1.139 GB
Notification: Performance of simCode: created event and clocks part: time 4.208e-06/1.176, allocations: 0 / 1.406 GB, free: 13.55 MB / 1.139 GB
Notification: Performance of simCode: created simulation system equations: time 0.0005418/1.177, allocations: 374.1 kB / 1.406 GB, free: 13.18 MB / 1.139 GB
Notification: Performance of simCode: created of all other equations (e.g. parameter, nominal, assert, etc): time 0.002365/1.179, allocations: 0.5408 MB / 1.406 GB, free: 12.65 MB / 1.139 GB
Notification: Performance of simCode: created linear, non-linear and system jacobian parts: time 0.00297/1.182, allocations: 1.924 MB / 1.408 GB, free: 10.65 MB / 1.139 GB
Notification: Performance of simCode: some other stuff during SimCode phase: time 0.0006656/1.183, allocations: 1.081 MB / 1.409 GB, free: 9.535 MB / 1.139 GB
Notification: Performance of simCode: alias equations: time 0.001184/1.184, allocations: 413.9 kB / 1.41 GB, free: 9.129 MB / 1.139 GB
Notification: Performance of simCode: all other stuff during SimCode phase: time 0.0002256/1.184, allocations: 71.44 kB / 1.41 GB, free: 9.059 MB / 1.139 GB
Notification: Performance of SimCode: time 5.81e-07/1.184, allocations: 0 / 1.41 GB, free: 9.059 MB / 1.139 GB
Notification: Performance of Templates: time 0.03818/1.222, allocations: 23 MB / 1.432 GB, free: 2.285 MB / 1.154 GB
make -j1 -f Buildings_10_Buildings.Fluid.MixingVolumes.Validation.MixingVolumeInitialization.makefile
(rm -f Buildings_10_Buildings.Fluid.MixingVolumes.Validation.MixingVolumeInitialization.pipe ; mkfifo Buildings_10_Buildings.Fluid.MixingVolumes.Validation.MixingVolumeInitialization.pipe ; head -c 1048576 < Buildings_10_Buildings.Fluid.MixingVolumes.Validation.MixingVolumeInitialization.pipe >> ../files/Buildings_10_Buildings.Fluid.MixingVolumes.Validation.MixingVolumeInitialization.sim & ./Buildings_10_Buildings.Fluid.MixingVolumes.Validation.MixingVolumeInitialization  -abortSlowSimulation -alarm=480  -emit_protected -lv LOG_STATS > Buildings_10_Buildings.Fluid.MixingVolumes.Validation.MixingVolumeInitialization.pipe 2>&1)
diffSimulationResults("Buildings_10_Buildings.Fluid.MixingVolumes.Validation.MixingVolumeInitialization_res.mat","/mnt/ReferenceFiles/Buildings/csv/maint_10.0.x/Buildings_Fluid_MixingVolumes_Validation_MixingVolumeInitialization.csv","/var/lib/jenkins/ws/OpenModelicaLibraryTestingWork/OpenModelicaLibraryTesting/files/Buildings_10_Buildings.Fluid.MixingVolumes.Validation.MixingVolumeInitialization.diff",relTol=0.003,relTolDiffMinMax=0.003,rangeDelta=0.001)
Reference file matches