Running: ./testmodel.py --libraries=/home/hudson/saved_omc/libraries/.openmodelica/libraries --ompython_omhome=/usr Buildings_10_Buildings.Examples.Tutorial.CDL.Controls.Validation.BoilerReturn.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.Examples.Tutorial.CDL.Controls.Validation.BoilerReturn,tolerance=1e-06,outputFormat="mat",numberOfIntervals=5000,variableFilter="time|conBoiRet.TSet|conBoiRet.TRet|conBoiRet.yVal",fileNamePrefix="Buildings_10_Buildings.Examples.Tutorial.CDL.Controls.Validation.BoilerReturn")
translateModel(Buildings.Examples.Tutorial.CDL.Controls.Validation.BoilerReturn,tolerance=1e-06,outputFormat="mat",numberOfIntervals=5000,variableFilter="time|conBoiRet.TSet|conBoiRet.TRet|conBoiRet.yVal",fileNamePrefix="Buildings_10_Buildings.Examples.Tutorial.CDL.Controls.Validation.BoilerReturn")
Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/ModelicaServices 4.0.0+maint.om/package.mo): time 0.00109/0.00109, allocations: 115.5 kB / 16.37 MB, free: 6.004 MB / 14.72 MB
Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Complex 4.0.0+maint.om/package.mo): time 0.001019/0.001019, allocations: 195.6 kB / 17.31 MB, free: 5.613 MB / 14.72 MB
Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Modelica 4.0.0+maint.om/package.mo): time 1.213/1.213, allocations: 222.9 MB / 241 MB, free: 15.16 MB / 206.1 MB
Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Buildings 10.1.0-maint.10.0.x/package.mo): time 2.215/2.215, allocations: 437.1 MB / 0.7112 GB, free: 4.367 MB / 0.5762 GB
Notification: Performance of FrontEnd - loaded program: time 0.001284/0.001284, allocations: 61.03 kB / 0.8707 GB, free: 1.41 MB / 0.6387 GB
Notification: Performance of FrontEnd - Absyn->SCode: time 0.2494/0.2507, allocations: 151.6 MB / 1.019 GB, free: 9.824 MB / 0.795 GB
Notification: Performance of NFInst.instantiate(Buildings.Examples.Tutorial.CDL.Controls.Validation.BoilerReturn): time 0.003064/0.2538, allocations: 2.045 MB / 1.021 GB, free: 7.758 MB / 0.795 GB
Notification: Performance of NFInst.instExpressions: time 0.0007131/0.2545, allocations: 442.7 kB / 1.021 GB, free: 7.324 MB / 0.795 GB
Notification: Performance of NFInst.updateImplicitVariability: time 0.0001131/0.2547, allocations: 4 kB / 1.021 GB, free: 7.32 MB / 0.795 GB
Notification: Performance of NFTyping.typeComponents: time 0.0001504/0.2548, allocations: 43.59 kB / 1.021 GB, free: 7.277 MB / 0.795 GB
Notification: Performance of NFTyping.typeBindings: time 8.432e-05/0.2549, allocations: 31.66 kB / 1.021 GB, free: 7.246 MB / 0.795 GB
Notification: Performance of NFTyping.typeClassSections: time 0.0002149/0.2552, allocations: 107.8 kB / 1.021 GB, free: 7.141 MB / 0.795 GB
Notification: Performance of NFFlatten.flatten: time 0.0002639/0.2554, allocations: 296.4 kB / 1.022 GB, free: 6.852 MB / 0.795 GB
Notification: Performance of NFFlatten.resolveConnections: time 0.00024/0.2557, allocations: 157.4 kB / 1.022 GB, free: 6.691 MB / 0.795 GB
Notification: Performance of NFEvalConstants.evaluate: time 0.0001064/0.2558, allocations: 103.6 kB / 1.022 GB, free: 6.59 MB / 0.795 GB
Notification: Performance of NFSimplifyModel.simplify: time 0.000101/0.2559, allocations: 99.48 kB / 1.022 GB, free: 6.492 MB / 0.795 GB
Notification: Performance of NFPackage.collectConstants: time 3.828e-05/0.2559, allocations: 32 kB / 1.022 GB, free: 6.461 MB / 0.795 GB
Notification: Performance of NFFlatten.collectFunctions: time 3.297e-05/0.256, allocations: 36 kB / 1.022 GB, free: 6.426 MB / 0.795 GB
Notification: Performance of NFScalarize.scalarize: time 5.5e-05/0.256, allocations: 59.84 kB / 1.022 GB, free: 6.367 MB / 0.795 GB
Notification: Performance of NFVerifyModel.verify: time 9.44e-05/0.2561, allocations: 127.3 kB / 1.022 GB, free: 6.242 MB / 0.795 GB
Notification: Performance of NFConvertDAE.convert: time 0.0003104/0.2565, allocations: 398.6 kB / 1.023 GB, free: 5.852 MB / 0.795 GB
Notification: Performance of FrontEnd - DAE generated: time 3.356e-06/0.2565, allocations: 0 / 1.023 GB, free: 5.852 MB / 0.795 GB
Notification: Performance of FrontEnd: time 1.352e-06/0.2565, allocations: 0 / 1.023 GB, free: 5.852 MB / 0.795 GB
Notification: Performance of Transformations before backend: time 8.156e-06/0.2565, allocations: 4 kB / 1.023 GB, free: 5.848 MB / 0.795 GB
Notification: Model statistics after passing the front-end and creating the data structures used by the back-end:
 * Number of equations: 47
 * Number of variables: 47
Notification: Performance of Generate backend data structure: time 0.0007326/0.2572, allocations: 0.534 MB / 1.023 GB, free: 5.266 MB / 0.795 GB
Notification: Performance of prepare preOptimizeDAE: time 3.587e-05/0.2573, allocations: 8.031 kB / 1.023 GB, free: 5.258 MB / 0.795 GB
Notification: Performance of preOpt normalInlineFunction (simulation): time 5.971e-05/0.2573, allocations: 24.66 kB / 1.023 GB, free: 5.234 MB / 0.795 GB
Notification: Performance of preOpt evaluateParameters (simulation): time 0.000298/0.2576, allocations: 277.5 kB / 1.023 GB, free: 4.926 MB / 0.795 GB
Notification: Performance of preOpt simplifyIfEquations (simulation): time 1.801e-05/0.2577, allocations: 12.81 kB / 1.023 GB, free: 4.914 MB / 0.795 GB
Notification: Performance of preOpt expandDerOperator (simulation): time 3.267e-05/0.2577, allocations: 24.31 kB / 1.023 GB, free: 4.891 MB / 0.795 GB
Notification: Performance of preOpt clockPartitioning (simulation): time 0.0004138/0.2581, allocations: 234.3 kB / 1.024 GB, free: 4.648 MB / 0.795 GB
Notification: Performance of preOpt findStateOrder (simulation): time 1.059e-05/0.2581, allocations: 7.938 kB / 1.024 GB, free: 4.641 MB / 0.795 GB
Notification: Performance of preOpt replaceEdgeChange (simulation): time 2.019e-05/0.2582, allocations: 8 kB / 1.024 GB, free: 4.633 MB / 0.795 GB
Notification: Performance of preOpt inlineArrayEqn (simulation): time 6.793e-06/0.2582, allocations: 4 kB / 1.024 GB, free: 4.629 MB / 0.795 GB
Notification: Performance of preOpt removeEqualRHS (simulation): time 0.0003885/0.2586, allocations: 169 kB / 1.024 GB, free: 4.465 MB / 0.795 GB
Notification: Performance of preOpt removeSimpleEquations (simulation): time 0.001004/0.2596, allocations: 0.8403 MB / 1.025 GB, free: 3.566 MB / 0.795 GB
Notification: Performance of preOpt comSubExp (simulation): time 0.0004287/0.26, allocations: 178.8 kB / 1.025 GB, free: 3.383 MB / 0.795 GB
Notification: Performance of preOpt resolveLoops (simulation): time 0.0001881/0.2602, allocations: 100.7 kB / 1.025 GB, free: 3.281 MB / 0.795 GB
Notification: Performance of preOpt evalFunc (simulation): time 2.036e-05/0.2602, allocations: 4 kB / 1.025 GB, free: 3.277 MB / 0.795 GB
Notification: Performance of preOpt encapsulateWhenConditions (simulation): time 2.566e-05/0.2603, allocations: 34.56 kB / 1.025 GB, free: 3.234 MB / 0.795 GB
Notification: Performance of pre-optimization done (n=12): time 1.242e-06/0.2603, allocations: 0 / 1.025 GB, free: 3.234 MB / 0.795 GB
Notification: Performance of matching and sorting (n=12): time 0.0005526/0.2608, allocations: 225.5 kB / 1.025 GB, free: 3.008 MB / 0.795 GB
Notification: Performance of inlineWhenForInitialization (initialization): time 4.795e-05/0.2609, allocations: 85.11 kB / 1.025 GB, free: 2.906 MB / 0.795 GB
Notification: Performance of selectInitializationVariablesDAE (initialization): time 0.0002108/0.2611, allocations: 231.2 kB / 1.026 GB, free: 2.672 MB / 0.795 GB
Notification: Performance of collectPreVariables (initialization): time 1.869e-05/0.2611, allocations: 29.7 kB / 1.026 GB, free: 2.637 MB / 0.795 GB
Notification: Performance of collectInitialEqns (initialization): time 9.804e-05/0.2612, allocations: 160 kB / 1.026 GB, free: 2.473 MB / 0.795 GB
Notification: Performance of collectInitialBindings (initialization): time 3.054e-05/0.2613, allocations: 43.44 kB / 1.026 GB, free: 2.43 MB / 0.795 GB
Notification: Performance of simplifyInitialFunctions (initialization): time 5.665e-05/0.2613, allocations: 33.62 kB / 1.026 GB, free: 2.391 MB / 0.795 GB
Notification: Performance of setup shared object (initialization): time 9.79e-05/0.2614, allocations: 334.8 kB / 1.026 GB, free: 2.055 MB / 0.795 GB
Notification: Performance of preBalanceInitialSystem (initialization): time 0.0001729/0.2616, allocations: 72.75 kB / 1.026 GB, free: 1.98 MB / 0.795 GB
Notification: Performance of partitionIndependentBlocks (initialization): time 0.0001789/0.2618, allocations: 109.1 kB / 1.026 GB, free: 1.855 MB / 0.795 GB
Notification: Performance of analyzeInitialSystem (initialization): time 0.0003188/0.2621, allocations: 164.5 kB / 1.026 GB, free: 1.684 MB / 0.795 GB
Notification: Performance of solveInitialSystemEqSystem (initialization): time 4.839e-06/0.2621, allocations: 0 / 1.026 GB, free: 1.684 MB / 0.795 GB
Notification: Performance of matching and sorting (n=17) (initialization): time 0.0004006/0.2626, allocations: 205.3 kB / 1.027 GB, free: 1.477 MB / 0.795 GB
Notification: Performance of prepare postOptimizeDAE: time 1.382e-05/0.2626, allocations: 8 kB / 1.027 GB, free: 1.469 MB / 0.795 GB
Notification: Performance of postOpt simplifyComplexFunction (initialization): time 4.087e-06/0.2626, allocations: 0 / 1.027 GB, free: 1.469 MB / 0.795 GB
Notification: Performance of postOpt tearingSystem (initialization): time 1.471e-05/0.2626, allocations: 3.938 kB / 1.027 GB, free: 1.465 MB / 0.795 GB
Notification: Performance of postOpt solveSimpleEquations (initialization): time 0.000153/0.2628, allocations: 43.91 kB / 1.027 GB, free: 1.422 MB / 0.795 GB
Notification: Performance of postOpt calculateStrongComponentJacobians (initialization): time 7.263e-06/0.2628, allocations: 4 kB / 1.027 GB, free: 1.418 MB / 0.795 GB
Notification: Performance of postOpt simplifyAllExpressions (initialization): time 0.0001221/0.2629, allocations: 27.92 kB / 1.027 GB, free: 1.391 MB / 0.795 GB
Notification: Performance of postOpt collapseArrayExpressions (initialization): time 1.368e-05/0.2629, allocations: 11.98 kB / 1.027 GB, free: 1.379 MB / 0.795 GB
Notification: Performance of preBalanceInitialSystem (initialization_lambda0): time 0.0001775/0.2631, allocations: 152.7 kB / 1.027 GB, free: 1.227 MB / 0.795 GB
Notification: Performance of partitionIndependentBlocks (initialization_lambda0): time 0.000139/0.2633, allocations: 95.69 kB / 1.027 GB, free: 1.117 MB / 0.795 GB
Notification: Performance of analyzeInitialSystem (initialization_lambda0): time 0.0002358/0.2635, allocations: 144.4 kB / 1.027 GB, free: 0.9648 MB / 0.795 GB
Notification: Performance of solveInitialSystemEqSystem (initialization_lambda0): time 9.52e-07/0.2635, allocations: 0 / 1.027 GB, free: 0.9648 MB / 0.795 GB
Notification: Performance of matching and sorting (n=17) (initialization_lambda0): time 0.0003078/0.2638, allocations: 178.5 kB / 1.027 GB, free: 0.7852 MB / 0.795 GB
Notification: Performance of prepare postOptimizeDAE: time 6.342e-06/0.2638, allocations: 8.094 kB / 1.027 GB, free: 0.7773 MB / 0.795 GB
Notification: Performance of postOpt simplifyComplexFunction (initialization): time 4.118e-06/0.2638, allocations: 7.984 kB / 1.027 GB, free: 0.7695 MB / 0.795 GB
Notification: Performance of postOpt tearingSystem (initialization): time 3.256e-06/0.2639, allocations: 3.984 kB / 1.027 GB, free: 0.7656 MB / 0.795 GB
Notification: Performance of postOpt solveSimpleEquations (initialization): time 0.0001205/0.264, allocations: 35.86 kB / 1.027 GB, free: 0.7305 MB / 0.795 GB
Notification: Performance of postOpt calculateStrongComponentJacobians (initialization): time 2.034e-06/0.264, allocations: 0 / 1.027 GB, free: 0.7305 MB / 0.795 GB
Notification: Performance of postOpt simplifyAllExpressions (initialization): time 0.000107/0.2641, allocations: 23.89 kB / 1.027 GB, free: 0.707 MB / 0.795 GB
Notification: Performance of postOpt collapseArrayExpressions (initialization): time 9.408e-06/0.2641, allocations: 7.984 kB / 1.027 GB, free: 0.6992 MB / 0.795 GB
Notification: Model statistics after passing the back-end for initialization:
 * Number of independent subsystems: 4
 * Number of states: 0 ()
 * Number of discrete variables: 1 (conBoiRet.conPID.con1.y)
 * Number of discrete states: 0 ()
 * Number of clocked states: 0 ()
 * Top-level inputs: 0
Notification: Strong component statistics for initialization (17):
 * Single equations (assignments): 17
 * 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 9.067e-05/0.2642, allocations: 192.1 kB / 1.028 GB, free: 0.5039 MB / 0.795 GB
Notification: Performance of postOpt lateInlineFunction (simulation): time 3.76e-05/0.2642, allocations: 19.81 kB / 1.028 GB, free: 496 kB / 0.795 GB
Notification: Performance of postOpt wrapFunctionCalls (simulation): time 4.322e-05/0.2643, allocations: 21.34 kB / 1.028 GB, free: 480 kB / 0.795 GB
Notification: Performance of postOpt inlineArrayEqn (simulation): time 6.452e-06/0.2643, allocations: 7.984 kB / 1.028 GB, free: 472 kB / 0.795 GB
Notification: Performance of postOpt constantLinearSystem (simulation): time 3.526e-06/0.2643, allocations: 0 / 1.028 GB, free: 472 kB / 0.795 GB
Notification: Performance of postOpt simplifysemiLinear (simulation): time 2.735e-06/0.2643, allocations: 0 / 1.028 GB, free: 472 kB / 0.795 GB
Notification: Performance of postOpt removeSimpleEquations (simulation): time 0.0002707/0.2646, allocations: 297.5 kB / 1.028 GB, free: 124 kB / 0.795 GB
Notification: Performance of postOpt simplifyComplexFunction (simulation): time 1.052e-06/0.2646, allocations: 0 / 1.028 GB, free: 124 kB / 0.795 GB
Notification: Performance of postOpt solveSimpleEquations (simulation): time 0.0001413/0.2648, allocations: 27.97 kB / 1.028 GB, free: 96 kB / 0.795 GB
Notification: Performance of postOpt tearingSystem (simulation): time 1.733e-06/0.2648, allocations: 0 / 1.028 GB, free: 96 kB / 0.795 GB
Notification: Performance of postOpt inputDerivativesUsed (simulation): time 1.394e-05/0.2648, allocations: 3.938 kB / 1.028 GB, free: 92 kB / 0.795 GB
Notification: Performance of postOpt calculateStrongComponentJacobians (simulation): time 1.523e-06/0.2648, allocations: 11.94 kB / 1.028 GB, free: 80 kB / 0.795 GB
Notification: Performance of postOpt calculateStateSetsJacobians (simulation): time 9.12e-07/0.2648, allocations: 0 / 1.028 GB, free: 80 kB / 0.795 GB
Notification: Performance of postOpt symbolicJacobian (simulation): time 0.0005668/0.2654, allocations: 343.1 kB / 1.028 GB, free: 15.73 MB / 0.8106 GB
Notification: Performance of postOpt removeConstants (simulation): time 5.631e-05/0.2654, allocations: 101 kB / 1.028 GB, free: 15.61 MB / 0.8106 GB
Notification: Performance of postOpt simplifyTimeIndepFuncCalls (simulation): time 2.796e-05/0.2655, allocations: 11.94 kB / 1.028 GB, free: 15.6 MB / 0.8106 GB
Notification: Performance of postOpt simplifyAllExpressions (simulation): time 0.0001285/0.2656, allocations: 11.98 kB / 1.028 GB, free: 15.59 MB / 0.8106 GB
Notification: Performance of postOpt findZeroCrossings (simulation): time 3.609e-05/0.2656, allocations: 11.98 kB / 1.028 GB, free: 15.57 MB / 0.8106 GB
Notification: Performance of postOpt collapseArrayExpressions (simulation): time 1.021e-05/0.2657, allocations: 4 kB / 1.028 GB, free: 15.57 MB / 0.8106 GB
Notification: Performance of sorting global known variables: time 0.0001404/0.2658, allocations: 164.7 kB / 1.029 GB, free: 15.41 MB / 0.8106 GB
Notification: Performance of sort global known variables: time 1.5e-07/0.2658, allocations: 4 kB / 1.029 GB, free: 15.41 MB / 0.8106 GB
Notification: Performance of remove unused functions: time 0.0003301/0.2661, allocations: 67.69 kB / 1.029 GB, free: 15.34 MB / 0.8106 GB
Notification: Model statistics after passing the back-end for simulation:
 * Number of independent subsystems: 1
 * Number of states: 1 (conBoiRet.conPID.I.y)
 * 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 (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 Backend phase and start with SimCode phase: time 9.727e-05/0.2662, allocations: 99.25 kB / 1.029 GB, free: 15.23 MB / 0.8106 GB
Notification: Performance of simCode: created initialization part: time 0.0004967/0.2668, allocations: 224.4 kB / 1.029 GB, free: 15.02 MB / 0.8106 GB
Notification: Performance of simCode: created event and clocks part: time 1.883e-06/0.2668, allocations: 0 / 1.029 GB, free: 15.02 MB / 0.8106 GB
Notification: Performance of simCode: created simulation system equations: time 0.0001605/0.2669, allocations: 76.27 kB / 1.029 GB, free: 14.94 MB / 0.8106 GB
Notification: Performance of simCode: created of all other equations (e.g. parameter, nominal, assert, etc): time 0.0003433/0.2673, allocations: 36.59 kB / 1.029 GB, free: 14.9 MB / 0.8106 GB
Notification: Performance of simCode: created linear, non-linear and system jacobian parts: time 0.0006202/0.2679, allocations: 385.4 kB / 1.029 GB, free: 14.5 MB / 0.8106 GB
Notification: Performance of simCode: some other stuff during SimCode phase: time 0.0002508/0.2682, allocations: 0.7363 MB / 1.03 GB, free: 13.74 MB / 0.8106 GB
Notification: Performance of simCode: alias equations: time 8.042e-05/0.2683, allocations: 25.53 kB / 1.03 GB, free: 13.71 MB / 0.8106 GB
Notification: Performance of simCode: all other stuff during SimCode phase: time 4.968e-05/0.2683, allocations: 15.44 kB / 1.03 GB, free: 13.7 MB / 0.8106 GB
Notification: Performance of SimCode: time 2.1e-07/0.2683, allocations: 3.938 kB / 1.03 GB, free: 13.7 MB / 0.8106 GB
Notification: Performance of Templates: time 0.004455/0.2728, allocations: 2.006 MB / 1.032 GB, free: 11.72 MB / 0.8106 GB
make -j1 -f Buildings_10_Buildings.Examples.Tutorial.CDL.Controls.Validation.BoilerReturn.makefile
(rm -f Buildings_10_Buildings.Examples.Tutorial.CDL.Controls.Validation.BoilerReturn.pipe ; mkfifo Buildings_10_Buildings.Examples.Tutorial.CDL.Controls.Validation.BoilerReturn.pipe ; head -c 1048576 < Buildings_10_Buildings.Examples.Tutorial.CDL.Controls.Validation.BoilerReturn.pipe >> ../files/Buildings_10_Buildings.Examples.Tutorial.CDL.Controls.Validation.BoilerReturn.sim & ./Buildings_10_Buildings.Examples.Tutorial.CDL.Controls.Validation.BoilerReturn  -abortSlowSimulation -alarm=480 -s cvode -emit_protected -lv LOG_STATS > Buildings_10_Buildings.Examples.Tutorial.CDL.Controls.Validation.BoilerReturn.pipe 2>&1)
diffSimulationResults("Buildings_10_Buildings.Examples.Tutorial.CDL.Controls.Validation.BoilerReturn_res.mat","/mnt/ReferenceFiles/Buildings/csv/maint_10.0.x/Buildings_Examples_Tutorial_CDL_Controls_Validation_BoilerReturn.csv","/var/lib/jenkins1/ws/OpenModelicaLibraryTestingWork/OpenModelicaLibraryTesting/files/Buildings_10_Buildings.Examples.Tutorial.CDL.Controls.Validation.BoilerReturn.diff",relTol=0.003,relTolDiffMinMax=0.003,rangeDelta=0.001)
Reference file matches