Running: ./testmodel.py --libraries=/home/hudson/saved_omc/libraries/.openmodelica/libraries --ompython_omhome=/usr Buildings_10_Buildings.Fluid.Interfaces.Examples.ReverseFlowMassExchanger.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 10.1.0-maint.10.0.x/package.mo", uses=false)
Using package Buildings with version 10.1.0 (/home/hudson/saved_omc/libraries/.openmodelica/libraries/Buildings 10.1.0-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.Interfaces.Examples.ReverseFlowMassExchanger,tolerance=1e-06,outputFormat="mat",numberOfIntervals=5000,variableFilter="time|senEnt1.h_out|senEnt2.h_out|senTem1.T|senTem2.T|senMas1.X|senMas2.X|cheTem.y|cheEnt.y|cheMas.y|cheTem1.y|cheEnt1.y|cheMas1.y",fileNamePrefix="Buildings_10_Buildings.Fluid.Interfaces.Examples.ReverseFlowMassExchanger")
translateModel(Buildings.Fluid.Interfaces.Examples.ReverseFlowMassExchanger,tolerance=1e-06,outputFormat="mat",numberOfIntervals=5000,variableFilter="time|senEnt1.h_out|senEnt2.h_out|senTem1.T|senTem2.T|senMas1.X|senMas2.X|cheTem.y|cheEnt.y|cheMas.y|cheTem1.y|cheEnt1.y|cheMas1.y",fileNamePrefix="Buildings_10_Buildings.Fluid.Interfaces.Examples.ReverseFlowMassExchanger")
Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/ModelicaServices 4.0.0+maint.om/package.mo): time 0.0009877/0.0009878, allocations: 99.5 kB / 16.02 MB, free: 76 kB / 14.72 MB
Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Complex 4.0.0+maint.om/package.mo): time 0.001253/0.001253, allocations: 185.5 kB / 16.92 MB, free: 6.703 MB / 14.72 MB
Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Modelica 4.0.0+maint.om/package.mo): time 1.317/1.317, allocations: 223.3 MB / 241 MB, free: 5.352 MB / 190.1 MB
Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Buildings 10.1.0-maint.10.0.x/package.mo): time 2.516/2.516, allocations: 437.8 MB / 0.7128 GB, free: 7.004 MB / 0.5606 GB
Notification: Performance of FrontEnd - loaded program: time 0.0004035/0.0004038, allocations: 23.98 kB / 0.8735 GB, free: 3.312 MB / 0.7169 GB
Notification: Performance of FrontEnd - Absyn->SCode: time 0.6841/0.6845, allocations: 153.8 MB / 1.024 GB, free: 15.87 MB / 0.7794 GB
Notification: Performance of NFInst.instantiate(Buildings.Fluid.Interfaces.Examples.ReverseFlowMassExchanger): time 0.9511/1.636, allocations: 321.9 MB / 1.338 GB, free: 1.121 MB / 0.9825 GB
Notification: Performance of NFInst.instExpressions: time 0.03062/1.666, allocations: 29.92 MB / 1.367 GB, free: 15.7 MB / 0.9981 GB
Notification: Performance of NFInst.updateImplicitVariability: time 0.005542/1.672, allocations: 87.75 kB / 1.367 GB, free: 15.7 MB / 0.9981 GB
Notification: Performance of NFTyping.typeComponents: time 0.006558/1.679, allocations: 1.753 MB / 1.369 GB, free: 15.31 MB / 0.9981 GB
Notification: Performance of NFTyping.typeBindings: time 0.0138/1.692, allocations: 4.706 MB / 1.374 GB, free: 14.22 MB / 0.9981 GB
Notification: Performance of NFTyping.typeClassSections: time 0.009338/1.702, allocations: 3.335 MB / 1.377 GB, free: 13.08 MB / 0.9981 GB
Notification: Performance of NFFlatten.flatten: time 0.01243/1.714, allocations: 9.642 MB / 1.386 GB, free: 9.816 MB / 0.9981 GB
Notification: Performance of NFFlatten.resolveConnections: time 0.003932/1.718, allocations: 2.362 MB / 1.389 GB, free: 8.465 MB / 0.9981 GB
Notification: Performance of NFEvalConstants.evaluate: time 0.01402/1.732, allocations: 4.679 MB / 1.393 GB, free: 6.434 MB / 0.9981 GB
Notification: Performance of NFSimplifyModel.simplify: time 0.005975/1.738, allocations: 2.401 MB / 1.396 GB, free: 5.285 MB / 0.9981 GB
Notification: Performance of NFPackage.collectConstants: time 0.0008755/1.739, allocations: 129.9 kB / 1.396 GB, free: 5.285 MB / 0.9981 GB
Notification: Performance of NFFlatten.collectFunctions: time 0.01099/1.75, allocations: 5.587 MB / 1.401 GB, free: 2.68 MB / 0.9981 GB
Notification: Performance of NFScalarize.scalarize: time 0.001568/1.752, allocations: 0.8913 MB / 1.402 GB, free: 2.102 MB / 0.9981 GB
Notification: Performance of NFVerifyModel.verify: time 0.002808/1.755, allocations: 1.57 MB / 1.404 GB, free: 1.137 MB / 0.9981 GB
Notification: Performance of NFConvertDAE.convert: time 0.006951/1.761, allocations: 4.149 MB / 1.408 GB, free: 14.7 MB / 1.014 GB
Notification: Performance of FrontEnd - DAE generated: time 5.39e-06/1.762, allocations: 0 / 1.408 GB, free: 14.7 MB / 1.014 GB
Notification: Performance of FrontEnd: time 3.346e-06/1.762, allocations: 2.562 kB / 1.408 GB, free: 14.7 MB / 1.014 GB
Notification: Performance of Transformations before backend: time 8.854e-05/1.762, allocations: 3.938 kB / 1.408 GB, free: 14.7 MB / 1.014 GB
Notification: Model statistics after passing the front-end and creating the data structures used by the back-end:
 * Number of equations: 536
 * Number of variables: 536
Notification: Performance of Generate backend data structure: time 0.007107/1.769, allocations: 3.045 MB / 1.411 GB, free: 11.76 MB / 1.014 GB
Notification: Performance of prepare preOptimizeDAE: time 4.145e-05/1.769, allocations: 12.03 kB / 1.411 GB, free: 11.75 MB / 1.014 GB
Notification: Performance of preOpt normalInlineFunction (simulation): time 0.009808/1.779, allocations: 1.58 MB / 1.412 GB, free: 10.16 MB / 1.014 GB
Notification: Performance of preOpt evaluateParameters (simulation): time 0.004315/1.783, allocations: 1.998 MB / 1.414 GB, free: 8.133 MB / 1.014 GB
Notification: Performance of preOpt simplifyIfEquations (simulation): time 0.001316/1.784, allocations: 431.9 kB / 1.414 GB, free: 7.711 MB / 1.014 GB
Notification: Performance of preOpt expandDerOperator (simulation): time 0.0005092/1.785, allocations: 216 kB / 1.415 GB, free: 7.5 MB / 1.014 GB
Notification: Performance of preOpt clockPartitioning (simulation): time 0.006397/1.791, allocations: 3.108 MB / 1.418 GB, free: 4.258 MB / 1.014 GB
Notification: Performance of preOpt findStateOrder (simulation): time 4.173e-05/1.791, allocations: 4 kB / 1.418 GB, free: 4.254 MB / 1.014 GB
Notification: Performance of preOpt replaceEdgeChange (simulation): time 0.0002748/1.792, allocations: 91.75 kB / 1.418 GB, free: 4.168 MB / 1.014 GB
Notification: Performance of preOpt inlineArrayEqn (simulation): time 9.311e-05/1.792, allocations: 92 kB / 1.418 GB, free: 4.074 MB / 1.014 GB
Notification: Performance of preOpt removeEqualRHS (simulation): time 0.007846/1.8, allocations: 3.228 MB / 1.421 GB, free: 0.8281 MB / 1.014 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 0.02852/1.828, allocations: 14.28 MB / 1.435 GB, free: 1.562 MB / 1.029 GB
Notification: Performance of preOpt comSubExp (simulation): time 0.004306/1.832, allocations: 1.692 MB / 1.437 GB, free: 15.86 MB / 1.045 GB
Notification: Performance of preOpt resolveLoops (simulation): time 0.001865/1.834, allocations: 0.7937 MB / 1.437 GB, free: 15.06 MB / 1.045 GB
Notification: Performance of preOpt evalFunc (simulation): time 0.0006658/1.835, allocations: 343.4 kB / 1.438 GB, free: 14.68 MB / 1.045 GB
Notification: Performance of preOpt encapsulateWhenConditions (simulation): time 4.921e-05/1.835, allocations: 55.55 kB / 1.438 GB, free: 14.62 MB / 1.045 GB
Notification: Performance of preOpt simplifyInStream (simulation): time 0.001537/1.837, allocations: 193.3 kB / 1.438 GB, free: 14.43 MB / 1.045 GB
Notification: Performance of pre-optimization done (n=110): time 7.133e-06/1.837, allocations: 0 / 1.438 GB, free: 14.43 MB / 1.045 GB
Notification: Performance of matching and sorting (n=110): time 0.006422/1.843, allocations: 2.41 MB / 1.44 GB, free: 12.01 MB / 1.045 GB
Notification: Performance of inlineWhenForInitialization (initialization): time 5.887e-05/1.843, allocations: 64.41 kB / 1.44 GB, free: 11.94 MB / 1.045 GB
Notification: Performance of selectInitializationVariablesDAE (initialization): time 0.004982/1.848, allocations: 2.564 MB / 1.443 GB, free: 9.355 MB / 1.045 GB
Notification: Performance of collectPreVariables (initialization): time 0.0003211/1.849, allocations: 61.64 kB / 1.443 GB, free: 9.289 MB / 1.045 GB
Notification: Performance of collectInitialEqns (initialization): time 0.001168/1.85, allocations: 1.263 MB / 1.444 GB, free: 8.016 MB / 1.045 GB
Notification: Performance of collectInitialBindings (initialization): time 0.0004696/1.85, allocations: 389 kB / 1.445 GB, free: 7.641 MB / 1.045 GB
Notification: Performance of simplifyInitialFunctions (initialization): time 0.0003182/1.851, allocations: 137.6 kB / 1.445 GB, free: 7.5 MB / 1.045 GB
Notification: Performance of setup shared object (initialization): time 9.738e-05/1.851, allocations: 309 kB / 1.445 GB, free: 7.195 MB / 1.045 GB
Notification: Performance of preBalanceInitialSystem (initialization): time 0.002853/1.853, allocations: 0.9915 MB / 1.446 GB, free: 6.203 MB / 1.045 GB
Notification: Performance of partitionIndependentBlocks (initialization): time 0.003434/1.857, allocations: 1.636 MB / 1.448 GB, free: 4.301 MB / 1.045 GB
Notification: Performance of analyzeInitialSystem (initialization): time 0.00522/1.862, allocations: 2.298 MB / 1.45 GB, free: 1.809 MB / 1.045 GB
Notification: Performance of solveInitialSystemEqSystem (initialization): time 1.888e-05/1.862, allocations: 4 kB / 1.45 GB, free: 1.805 MB / 1.045 GB
Notification: Performance of matching and sorting (n=210) (initialization): time 0.007493/1.87, allocations: 2.864 MB / 1.453 GB, free: 14.92 MB / 1.061 GB
Notification: Performance of prepare postOptimizeDAE: time 0.0004636/1.87, allocations: 0.5447 MB / 1.453 GB, free: 14.17 MB / 1.061 GB
Notification: Performance of postOpt simplifyComplexFunction (initialization): time 2.672e-05/1.87, allocations: 16 kB / 1.453 GB, free: 14.16 MB / 1.061 GB
Notification: Performance of postOpt tearingSystem (initialization): time 3.743e-05/1.87, allocations: 20 kB / 1.453 GB, free: 14.14 MB / 1.061 GB
Notification: Performance of postOpt solveSimpleEquations (initialization): time 0.003103/1.873, allocations: 0.5734 MB / 1.454 GB, free: 13.56 MB / 1.061 GB
Notification: Performance of postOpt calculateStrongComponentJacobians (initialization): time 0.001626/1.875, allocations: 2.395 MB / 1.456 GB, free: 11.07 MB / 1.061 GB
Notification: Performance of postOpt simplifyAllExpressions (initialization): time 0.004293/1.879, allocations: 443.5 kB / 1.457 GB, free: 10.64 MB / 1.061 GB
Notification: Performance of postOpt collapseArrayExpressions (initialization): time 0.0004032/1.88, allocations: 87.95 kB / 1.457 GB, free: 10.55 MB / 1.061 GB
Notification: Performance of prepare postOptimizeDAE: time 1.609e-05/1.88, allocations: 6.969 kB / 1.457 GB, free: 10.55 MB / 1.061 GB
Notification: Performance of postOpt replaceHomotopyWithSimplified (initialization): time 0.007031/1.887, allocations: 2.624 MB / 1.459 GB, free: 7.914 MB / 1.061 GB
Notification: Performance of postOpt simplifyComplexFunction (initialization): time 3.509e-05/1.887, allocations: 12 kB / 1.459 GB, free: 7.902 MB / 1.061 GB
Notification: Performance of postOpt tearingSystem (initialization): time 3.051e-05/1.887, allocations: 20 kB / 1.459 GB, free: 7.883 MB / 1.061 GB
Notification: Performance of postOpt solveSimpleEquations (initialization): time 0.002663/1.89, allocations: 0.5348 MB / 1.46 GB, free: 7.348 MB / 1.061 GB
Notification: Performance of postOpt calculateStrongComponentJacobians (initialization): time 4.588e-05/1.89, allocations: 27.94 kB / 1.46 GB, free: 7.32 MB / 1.061 GB
Notification: Performance of postOpt simplifyAllExpressions (initialization): time 0.003656/1.893, allocations: 375.4 kB / 1.46 GB, free: 6.953 MB / 1.061 GB
Notification: Performance of postOpt collapseArrayExpressions (initialization): time 0.0003008/1.894, allocations: 86.23 kB / 1.46 GB, free: 6.871 MB / 1.061 GB
Notification: Model statistics after passing the back-end for initialization:
 * Number of independent subsystems: 59
 * Number of states: 0 ()
 * Number of discrete variables: 4 (masExcRev.i2_w,masExcRev.i1_w,masExcFor.i2_w,masExcFor.i1_w)
 * Number of discrete states: 0 ()
 * Number of clocked states: 0 ()
 * Top-level inputs: 0
Notification: Strong component statistics for initialization (208):
 * Single equations (assignments): 202
 * Array equations: 0
 * Algorithm blocks: 2
 * Record equations: 0
 * When equations: 0
 * If-equations: 0
 * Equation systems (not torn): 4
 * Torn equation systems: 0
 * 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): 4 systems
   {1, 1, 1, 1}
 * Without analytic Jacobian (size): 0 systems
Notification: Performance of prepare postOptimizeDAE: time 0.001558/1.895, allocations: 0.6216 MB / 1.461 GB, free: 6.238 MB / 1.061 GB
Notification: Performance of postOpt lateInlineFunction (simulation): time 0.000771/1.896, allocations: 264.7 kB / 1.461 GB, free: 5.977 MB / 1.061 GB
Notification: Performance of postOpt wrapFunctionCalls (simulation): time 0.005003/1.901, allocations: 1.898 MB / 1.463 GB, free: 4.07 MB / 1.061 GB
Notification: Performance of postOpt inlineArrayEqn (simulation): time 1.033e-05/1.901, allocations: 8 kB / 1.463 GB, free: 4.062 MB / 1.061 GB
Notification: Performance of postOpt constantLinearSystem (simulation): time 1.124e-05/1.901, allocations: 7.938 kB / 1.463 GB, free: 4.055 MB / 1.061 GB
Notification: Performance of postOpt simplifysemiLinear (simulation): time 1.349e-05/1.901, allocations: 3.984 kB / 1.463 GB, free: 4.051 MB / 1.061 GB
Notification: Performance of postOpt removeSimpleEquations (simulation): time 0.01115/1.912, allocations: 4.536 MB / 1.467 GB, free: 15.4 MB / 1.076 GB
Notification: Performance of postOpt simplifyComplexFunction (simulation): time 1.546e-05/1.912, allocations: 7.938 kB / 1.467 GB, free: 15.39 MB / 1.076 GB
Notification: Performance of postOpt solveSimpleEquations (simulation): time 0.001711/1.914, allocations: 316.3 kB / 1.468 GB, free: 15.09 MB / 1.076 GB
Notification: Performance of postOpt tearingSystem (simulation): time 2.876e-05/1.914, allocations: 12 kB / 1.468 GB, free: 15.07 MB / 1.076 GB
Notification: Performance of postOpt inputDerivativesUsed (simulation): time 9.658e-05/1.914, allocations: 27.98 kB / 1.468 GB, free: 15.05 MB / 1.076 GB
Notification: Performance of postOpt calculateStrongComponentJacobians (simulation): time 0.00125/1.915, allocations: 2.375 MB / 1.47 GB, free: 12.58 MB / 1.076 GB
Notification: Performance of postOpt calculateStateSetsJacobians (simulation): time 8.406e-06/1.915, allocations: 8 kB / 1.47 GB, free: 12.57 MB / 1.076 GB
Notification: Performance of postOpt symbolicJacobian (simulation): time 0.004819/1.92, allocations: 2.01 MB / 1.472 GB, free: 10.46 MB / 1.076 GB
Notification: Performance of postOpt removeConstants (simulation): time 0.001761/1.922, allocations: 0.5444 MB / 1.473 GB, free: 9.898 MB / 1.076 GB
Notification: Performance of postOpt simplifyTimeIndepFuncCalls (simulation): time 0.0007018/1.923, allocations: 27.98 kB / 1.473 GB, free: 9.871 MB / 1.076 GB
Notification: Performance of postOpt simplifyAllExpressions (simulation): time 0.003201/1.926, allocations: 285.7 kB / 1.473 GB, free: 9.594 MB / 1.076 GB
Notification: Performance of postOpt findZeroCrossings (simulation): time 0.00018/1.926, allocations: 88.7 kB / 1.473 GB, free: 9.504 MB / 1.076 GB
Notification: Performance of postOpt collapseArrayExpressions (simulation): time 0.000218/1.926, allocations: 63.95 kB / 1.473 GB, free: 9.441 MB / 1.076 GB
Notification: Performance of sorting global known variables: time 0.004246/1.931, allocations: 1.77 MB / 1.475 GB, free: 7.668 MB / 1.076 GB
Notification: Performance of sort global known variables: time 3e-07/1.931, allocations: 0 / 1.475 GB, free: 7.668 MB / 1.076 GB
Notification: Performance of remove unused functions: time 0.00518/1.936, allocations: 1.298 MB / 1.476 GB, free: 6.367 MB / 1.076 GB
Notification: Model statistics after passing the back-end for simulation:
 * Number of independent subsystems: 25
 * 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 (110):
 * Single equations (assignments): 106
 * Array equations: 0
 * Algorithm blocks: 0
 * Record equations: 0
 * When equations: 0
 * If-equations: 0
 * Equation systems (not torn): 4
 * Torn equation systems: 0
 * 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): 4 systems
   {1, 1, 1, 1}
 * Without analytic Jacobian (size): 0 systems
Notification: Performance of Backend phase and start with SimCode phase: time 0.001083/1.937, allocations: 393.4 kB / 1.476 GB, free: 6.008 MB / 1.076 GB
Notification: Performance of simCode: created initialization part: time 0.01001/1.947, allocations: 3.674 MB / 1.48 GB, free: 2.293 MB / 1.076 GB
Notification: Performance of simCode: created event and clocks part: time 1.323e-05/1.947, allocations: 4 kB / 1.48 GB, free: 2.289 MB / 1.076 GB
Notification: Performance of simCode: created simulation system equations: time 0.002509/1.95, allocations: 0.8321 MB / 1.481 GB, free: 1.461 MB / 1.076 GB
Notification: Performance of simCode: created of all other equations (e.g. parameter, nominal, assert, etc): time 0.01108/1.961, allocations: 1.327 MB / 1.482 GB, free: 152 kB / 1.076 GB
Notification: Performance of simCode: created linear, non-linear and system jacobian parts: time 0.01132/1.972, allocations: 5.349 MB / 1.487 GB, free: 10.69 MB / 1.092 GB
Notification: Performance of simCode: some other stuff during SimCode phase: time 0.002012/1.974, allocations: 1.685 MB / 1.489 GB, free: 8.965 MB / 1.092 GB
Notification: Performance of simCode: all other stuff during SimCode phase: time 0.001489/1.976, allocations: 251.3 kB / 1.489 GB, free: 8.719 MB / 1.092 GB
Notification: Performance of SimCode: time 1.363e-06/1.976, allocations: 0 / 1.489 GB, free: 8.719 MB / 1.092 GB
Notification: Performance of Templates: time 0.1095/2.085, allocations: 85.84 MB / 1.573 GB, free: 3.039 MB / 1.17 GB
make -j1 -f Buildings_10_Buildings.Fluid.Interfaces.Examples.ReverseFlowMassExchanger.makefile
(rm -f Buildings_10_Buildings.Fluid.Interfaces.Examples.ReverseFlowMassExchanger.pipe ; mkfifo Buildings_10_Buildings.Fluid.Interfaces.Examples.ReverseFlowMassExchanger.pipe ; head -c 1048576 < Buildings_10_Buildings.Fluid.Interfaces.Examples.ReverseFlowMassExchanger.pipe >> ../files/Buildings_10_Buildings.Fluid.Interfaces.Examples.ReverseFlowMassExchanger.sim & ./Buildings_10_Buildings.Fluid.Interfaces.Examples.ReverseFlowMassExchanger  -abortSlowSimulation -alarm=480  -emit_protected -lv LOG_STATS > Buildings_10_Buildings.Fluid.Interfaces.Examples.ReverseFlowMassExchanger.pipe 2>&1)
diffSimulationResults("Buildings_10_Buildings.Fluid.Interfaces.Examples.ReverseFlowMassExchanger_res.mat","/mnt/ReferenceFiles/Buildings/csv/maint_10.0.x/Buildings_Fluid_Interfaces_Examples_ReverseFlowMassExchanger.csv","/var/lib/jenkins1/ws/OpenModelicaLibraryTestingWork/OpenModelicaLibraryTesting/files/Buildings_10_Buildings.Fluid.Interfaces.Examples.ReverseFlowMassExchanger.diff",relTol=0.003,relTolDiffMinMax=0.003,rangeDelta=0.001)
Reference file matches