Running: ./testmodel.py --libraries=/home/hudson/saved_omc/libraries/.openmodelica/libraries --ompython_omhome=/usr Buildings_9_Buildings.Fluid.Geothermal.BuriedPipes.Examples.TwoPipesConduit.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 9.1.3-maint.9.1.x/package.mo", uses=false) Using package Buildings with version 9.1.3 (/home/hudson/saved_omc/libraries/.openmodelica/libraries/Buildings 9.1.3-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.Geothermal.BuriedPipes.Examples.TwoPipesConduit,tolerance=1e-06,outputFormat="mat",numberOfIntervals=5000,variableFilter="time|senTemInlSup.T|senTemOutSup.T|senTemOutRet.T|senTemInlRet.T|conAir.T|gro.ports.1|1..T",fileNamePrefix="Buildings_9_Buildings.Fluid.Geothermal.BuriedPipes.Examples.TwoPipesConduit") translateModel(Buildings.Fluid.Geothermal.BuriedPipes.Examples.TwoPipesConduit,tolerance=1e-06,outputFormat="mat",numberOfIntervals=5000,variableFilter="time|senTemInlSup.T|senTemOutSup.T|senTemOutRet.T|senTemInlRet.T|conAir.T|gro.ports.1|1..T",fileNamePrefix="Buildings_9_Buildings.Fluid.Geothermal.BuriedPipes.Examples.TwoPipesConduit") Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/ModelicaServices 4.0.0+maint.om/package.mo): time 0.001054/0.001054, allocations: 98.11 kB / 15.36 MB, free: 0.7344 MB / 14.72 MB Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Complex 4.0.0+maint.om/package.mo): time 0.009358/0.009358, allocations: 170.4 kB / 16.27 MB, free: 6.652 MB / 14.72 MB Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Modelica 4.0.0+maint.om/package.mo): time 1.411/1.411, allocations: 223.3 MB / 240.3 MB, free: 5.344 MB / 190.1 MB Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Buildings 9.1.3-maint.9.1.x/package.mo): time 2.363/2.363, allocations: 390.9 MB / 0.6663 GB, free: 2.379 MB / 0.5137 GB Notification: Performance of FrontEnd - loaded program: time 0.0003578/0.0003579, allocations: 8 kB / 0.816 GB, free: 13.23 MB / 0.67 GB Notification: Performance of FrontEnd - Absyn->SCode: time 0.683/0.6834, allocations: 142.4 MB / 0.955 GB, free: 7.715 MB / 0.7169 GB Notification: Performance of NFInst.instantiate(Buildings.Fluid.Geothermal.BuriedPipes.Examples.TwoPipesConduit): time 0.1101/0.7935, allocations: 116 MB / 1.068 GB, free: 11.01 MB / 0.8262 GB Notification: Performance of NFInst.instExpressions: time 0.03832/0.8319, allocations: 27.84 MB / 1.095 GB, free: 15.1 MB / 0.8575 GB Notification: Performance of NFInst.updateImplicitVariability: time 0.005436/0.8374, allocations: 115.2 kB / 1.096 GB, free: 14.99 MB / 0.8575 GB Notification: Performance of NFTyping.typeComponents: time 0.00473/0.8421, allocations: 1.243 MB / 1.097 GB, free: 13.74 MB / 0.8575 GB Notification: Performance of NFTyping.typeBindings: time 0.01352/0.8557, allocations: 4.272 MB / 1.101 GB, free: 9.449 MB / 0.8575 GB Notification: Performance of NFTyping.typeClassSections: time 0.008427/0.8641, allocations: 2.849 MB / 1.104 GB, free: 6.617 MB / 0.8575 GB Notification: Performance of NFFlatten.flatten: time 0.01485/0.879, allocations: 11.17 MB / 1.115 GB, free: 11.41 MB / 0.8731 GB Notification: Performance of NFFlatten.resolveConnections: time 0.004139/0.8832, allocations: 2.2 MB / 1.117 GB, free: 9.156 MB / 0.8731 GB Notification: Performance of NFEvalConstants.evaluate: time 0.007088/0.8903, allocations: 2.835 MB / 1.12 GB, free: 6.309 MB / 0.8731 GB Notification: Performance of NFSimplifyModel.simplify: time 0.004616/0.8949, allocations: 2.29 MB / 1.122 GB, free: 4.008 MB / 0.8731 GB Notification: Performance of NFPackage.collectConstants: time 0.000715/0.8957, allocations: 120 kB / 1.122 GB, free: 3.891 MB / 0.8731 GB Notification: Performance of NFFlatten.collectFunctions: time 0.01031/0.906, allocations: 3.221 MB / 1.125 GB, free: 0.6484 MB / 0.8731 GB Notification: Performance of NFScalarize.scalarize: time 0.001171/0.9072, allocations: 0.5715 MB / 1.126 GB, free: 76 kB / 0.8731 GB Notification: Performance of NFVerifyModel.verify: time 0.003723/0.9109, allocations: 1.541 MB / 1.127 GB, free: 14.52 MB / 0.8887 GB Notification: Performance of NFConvertDAE.convert: time 0.02263/0.9336, allocations: 18.23 MB / 1.145 GB, free: 12.23 MB / 0.9044 GB Notification: Performance of FrontEnd - DAE generated: time 4.809e-06/0.9336, allocations: 0 / 1.145 GB, free: 12.23 MB / 0.9044 GB Notification: Performance of FrontEnd: time 2.685e-06/0.9336, allocations: 0 / 1.145 GB, free: 12.23 MB / 0.9044 GB Notification: Performance of Transformations before backend: time 9.59e-05/0.9337, allocations: 0 / 1.145 GB, free: 12.23 MB / 0.9044 GB Notification: Model statistics after passing the front-end and creating the data structures used by the back-end: * Number of equations: 445 * Number of variables: 445 Notification: Performance of Generate backend data structure: time 0.006991/0.9407, allocations: 3.06 MB / 1.148 GB, free: 9.102 MB / 0.9044 GB Notification: Performance of prepare preOptimizeDAE: time 4.022e-05/0.9408, allocations: 8.031 kB / 1.148 GB, free: 9.094 MB / 0.9044 GB Notification: Performance of preOpt normalInlineFunction (simulation): time 0.0009152/0.9417, allocations: 352 kB / 1.148 GB, free: 8.746 MB / 0.9044 GB Notification: Performance of preOpt evaluateParameters (simulation): time 0.004519/0.9462, allocations: 2.6 MB / 1.151 GB, free: 6.074 MB / 0.9044 GB Notification: Performance of preOpt simplifyIfEquations (simulation): time 0.0001029/0.9463, allocations: 139.5 kB / 1.151 GB, free: 5.938 MB / 0.9044 GB Notification: Performance of preOpt expandDerOperator (simulation): time 0.0003036/0.9466, allocations: 191.8 kB / 1.151 GB, free: 5.75 MB / 0.9044 GB Notification: Performance of preOpt clockPartitioning (simulation): time 0.003346/0.95, allocations: 1.924 MB / 1.153 GB, free: 3.758 MB / 0.9044 GB Notification: Performance of preOpt findStateOrder (simulation): time 4.86e-05/0.9501, allocations: 11.84 kB / 1.153 GB, free: 3.746 MB / 0.9044 GB Notification: Performance of preOpt replaceEdgeChange (simulation): time 0.0001692/0.9502, allocations: 72 kB / 1.153 GB, free: 3.676 MB / 0.9044 GB Notification: Performance of preOpt inlineArrayEqn (simulation): time 5.577e-05/0.9503, allocations: 51.98 kB / 1.153 GB, free: 3.625 MB / 0.9044 GB Notification: Performance of preOpt removeEqualRHS (simulation): time 0.002632/0.9529, allocations: 1.434 MB / 1.155 GB, free: 2.188 MB / 0.9044 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 0.01249/0.9654, allocations: 9.877 MB / 1.164 GB, free: 7.625 MB / 0.92 GB Notification: Performance of preOpt comSubExp (simulation): time 0.001858/0.9673, allocations: 1.025 MB / 1.165 GB, free: 6.59 MB / 0.92 GB Notification: Performance of preOpt resolveLoops (simulation): time 0.0009074/0.9682, allocations: 0.573 MB / 1.166 GB, free: 6.02 MB / 0.92 GB Notification: Performance of preOpt evalFunc (simulation): time 0.002394/0.9707, allocations: 3.088 MB / 1.169 GB, free: 2.25 MB / 0.92 GB Notification: Performance of preOpt encapsulateWhenConditions (simulation): time 3.961e-05/0.9707, allocations: 47.56 kB / 1.169 GB, free: 2.195 MB / 0.92 GB Notification: Performance of pre-optimization done (n=127): time 3.306e-06/0.9707, allocations: 0 / 1.169 GB, free: 2.195 MB / 0.92 GB Notification: Performance of matching and sorting (n=127): time 0.003532/0.9743, allocations: 1.799 MB / 1.171 GB, free: 372 kB / 0.92 GB Notification: Performance of inlineWhenForInitialization (initialization): time 4.635e-05/0.9743, allocations: 68.41 kB / 1.171 GB, free: 292 kB / 0.92 GB Notification: Performance of selectInitializationVariablesDAE (initialization): time 0.003134/0.9775, allocations: 2.181 MB / 1.173 GB, free: 14.09 MB / 0.9356 GB Notification: Performance of collectPreVariables (initialization): time 0.0001342/0.9776, allocations: 53.7 kB / 1.173 GB, free: 14.04 MB / 0.9356 GB Notification: Performance of collectInitialEqns (initialization): time 0.001007/0.9786, allocations: 1.185 MB / 1.174 GB, free: 12.84 MB / 0.9356 GB Notification: Performance of collectInitialBindings (initialization): time 0.0004322/0.9791, allocations: 457.4 kB / 1.174 GB, free: 12.38 MB / 0.9356 GB Notification: Performance of simplifyInitialFunctions (initialization): time 0.0001787/0.9792, allocations: 133.6 kB / 1.175 GB, free: 12.25 MB / 0.9356 GB Notification: Performance of setup shared object (initialization): time 0.000102/0.9794, allocations: 305.1 kB / 1.175 GB, free: 11.95 MB / 0.9356 GB Notification: Performance of preBalanceInitialSystem (initialization): time 0.0009196/0.9803, allocations: 0.4997 MB / 1.175 GB, free: 11.45 MB / 0.9356 GB Notification: Performance of partitionIndependentBlocks (initialization): time 0.001169/0.9815, allocations: 0.8687 MB / 1.176 GB, free: 10.44 MB / 0.9356 GB Notification: Performance of analyzeInitialSystem (initialization): time 0.002128/0.9836, allocations: 1.407 MB / 1.178 GB, free: 8.906 MB / 0.9356 GB Notification: Performance of solveInitialSystemEqSystem (initialization): time 5.941e-06/0.9836, allocations: 0 / 1.178 GB, free: 8.906 MB / 0.9356 GB Notification: Performance of matching and sorting (n=199) (initialization): time 0.003307/0.9869, allocations: 1.771 MB / 1.179 GB, free: 7.121 MB / 0.9356 GB Notification: Performance of prepare postOptimizeDAE: time 0.0002422/0.9872, allocations: 368.2 kB / 1.18 GB, free: 6.637 MB / 0.9356 GB Notification: Performance of postOpt simplifyComplexFunction (initialization): time 3.492e-05/0.9872, allocations: 16 kB / 1.18 GB, free: 6.621 MB / 0.9356 GB Notification: Performance of postOpt tearingSystem (initialization): time 0.0003129/0.9875, allocations: 60.81 kB / 1.18 GB, free: 6.559 MB / 0.9356 GB Notification: Performance of postOpt solveSimpleEquations (initialization): time 0.001223/0.9888, allocations: 347.4 kB / 1.18 GB, free: 6.219 MB / 0.9356 GB Notification: Performance of postOpt calculateStrongComponentJacobians (initialization): time 0.001387/0.9902, allocations: 1.44 MB / 1.181 GB, free: 4.641 MB / 0.9356 GB Notification: Performance of postOpt simplifyAllExpressions (initialization): time 0.00204/0.9922, allocations: 249.4 kB / 1.182 GB, free: 4.398 MB / 0.9356 GB Notification: Performance of postOpt collapseArrayExpressions (initialization): time 0.0001611/0.9924, allocations: 79.95 kB / 1.182 GB, free: 4.32 MB / 0.9356 GB Notification: Performance of prepare postOptimizeDAE: time 8.937e-06/0.9924, allocations: 5.562 kB / 1.182 GB, free: 4.316 MB / 0.9356 GB Notification: Performance of postOpt replaceHomotopyWithSimplified (initialization): time 0.002713/0.9951, allocations: 1.504 MB / 1.183 GB, free: 2.809 MB / 0.9356 GB Notification: Performance of postOpt simplifyComplexFunction (initialization): time 3.482e-05/0.9952, allocations: 15.98 kB / 1.183 GB, free: 2.793 MB / 0.9356 GB Notification: Performance of postOpt tearingSystem (initialization): time 0.0002374/0.9954, allocations: 72.69 kB / 1.183 GB, free: 2.719 MB / 0.9356 GB Notification: Performance of postOpt solveSimpleEquations (initialization): time 0.001187/0.9966, allocations: 343.5 kB / 1.184 GB, free: 2.383 MB / 0.9356 GB Notification: Performance of postOpt calculateStrongComponentJacobians (initialization): time 0.001228/0.9979, allocations: 1.448 MB / 1.185 GB, free: 0.8047 MB / 0.9356 GB Notification: Performance of postOpt simplifyAllExpressions (initialization): time 0.001966/0.9999, allocations: 230.6 kB / 1.185 GB, free: 0.5781 MB / 0.9356 GB Notification: Performance of postOpt collapseArrayExpressions (initialization): time 0.0001387/1, allocations: 79.97 kB / 1.185 GB, free: 0.5 MB / 0.9356 GB Notification: Model statistics after passing the back-end for initialization: * Number of independent subsystems: 41 * 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 (192): * Single equations (assignments): 186 * Array equations: 0 * Algorithm blocks: 0 * Record equations: 5 * When equations: 0 * If-equations: 0 * Equation systems (not torn): 0 * Torn equation systems: 1 * Mixed (continuous/discrete) equation systems: 0 Notification: Torn system details for strict tearing set: * Linear torn systems (#iteration vars, #inner vars, density): 1 system {(1,1,100.0%)} * Non-linear torn systems (#iteration vars, #inner vars): 0 systems Notification: Performance of prepare postOptimizeDAE: time 0.001089/1.001, allocations: 0.5749 MB / 1.186 GB, free: 15.91 MB / 0.9512 GB Notification: Performance of postOpt lateInlineFunction (simulation): time 0.000411/1.002, allocations: 256.8 kB / 1.186 GB, free: 15.66 MB / 0.9512 GB Notification: Performance of postOpt wrapFunctionCalls (simulation): time 0.003953/1.005, allocations: 2.213 MB / 1.188 GB, free: 13.45 MB / 0.9512 GB Notification: Performance of postOpt inlineArrayEqn (simulation): time 3.465e-05/1.006, allocations: 23.98 kB / 1.188 GB, free: 13.43 MB / 0.9512 GB Notification: Performance of postOpt constantLinearSystem (simulation): time 5.22e-06/1.006, allocations: 0 / 1.188 GB, free: 13.43 MB / 0.9512 GB Notification: Performance of postOpt simplifysemiLinear (simulation): time 0.002442/1.008, allocations: 1.611 MB / 1.19 GB, free: 11.77 MB / 0.9512 GB Notification: Performance of postOpt removeSimpleEquations (simulation): time 0.008974/1.017, allocations: 5.032 MB / 1.195 GB, free: 6.52 MB / 0.9512 GB Notification: Performance of postOpt simplifyComplexFunction (simulation): time 3.334e-05/1.017, allocations: 12.12 kB / 1.195 GB, free: 6.508 MB / 0.9512 GB Notification: Performance of postOpt solveSimpleEquations (simulation): time 0.001101/1.018, allocations: 275.6 kB / 1.195 GB, free: 6.238 MB / 0.9512 GB Notification: Performance of postOpt tearingSystem (simulation): time 0.0002865/1.018, allocations: 52.81 kB / 1.195 GB, free: 6.184 MB / 0.9512 GB Notification: Performance of postOpt inputDerivativesUsed (simulation): time 0.0001151/1.019, allocations: 55.97 kB / 1.195 GB, free: 6.129 MB / 0.9512 GB Notification: Performance of postOpt calculateStrongComponentJacobians (simulation): time 0.001312/1.02, allocations: 1.436 MB / 1.197 GB, free: 4.562 MB / 0.9512 GB Notification: Performance of postOpt calculateStateSetsJacobians (simulation): time 7.985e-06/1.02, allocations: 11.94 kB / 1.197 GB, free: 4.551 MB / 0.9512 GB Notification: Performance of postOpt symbolicJacobian (simulation): time 0.004686/1.025, allocations: 2.844 MB / 1.199 GB, free: 1.602 MB / 0.9512 GB Notification: Performance of postOpt removeConstants (simulation): time 0.001408/1.026, allocations: 0.6295 MB / 1.2 GB, free: 0.9492 MB / 0.9512 GB Notification: Performance of postOpt simplifyTimeIndepFuncCalls (simulation): time 0.000348/1.026, allocations: 47.94 kB / 1.2 GB, free: 0.9023 MB / 0.9512 GB Notification: Performance of postOpt simplifyAllExpressions (simulation): time 0.00162/1.028, allocations: 139.6 kB / 1.2 GB, free: 0.7656 MB / 0.9512 GB Notification: Performance of postOpt findZeroCrossings (simulation): time 0.0002377/1.028, allocations: 141 kB / 1.2 GB, free: 0.6289 MB / 0.9512 GB Notification: Performance of postOpt collapseArrayExpressions (simulation): time 0.0001446/1.028, allocations: 75.95 kB / 1.2 GB, free: 0.5547 MB / 0.9512 GB Notification: Performance of sorting global known variables: time 0.002612/1.031, allocations: 1.592 MB / 1.202 GB, free: 14.96 MB / 0.9669 GB Notification: Performance of sort global known variables: time 2.9e-07/1.031, allocations: 0 / 1.202 GB, free: 14.96 MB / 0.9669 GB Notification: Performance of remove unused functions: time 0.004497/1.036, allocations: 1.58 MB / 1.203 GB, free: 13.38 MB / 0.9669 GB Notification: Model statistics after passing the back-end for simulation: * Number of independent subsystems: 27 * Number of states: 14 (pipSup.del.x,pipSup.timDel.x,pipSup.vol_b.dynBal.U,pipSup.vol_a.dynBal.U,senTemInlSup.T,senTemOutSup.T,pipRet.del.x,pipRet.timDel.x,pipRet.vol_b.dynBal.U,pipRet.vol_a.dynBal.U,senTemOutRet.T,senTemInlRet.T,conAir.T,con.T[1]) * 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 (161): * Single equations (assignments): 132 * Array equations: 0 * Algorithm blocks: 0 * Record equations: 28 * When equations: 0 * If-equations: 0 * Equation systems (not torn): 0 * Torn equation systems: 1 * Mixed (continuous/discrete) equation systems: 0 Notification: Torn system details for strict tearing set: * Linear torn systems (#iteration vars, #inner vars, density): 1 system {(1,1,100.0%)} * Non-linear torn systems (#iteration vars, #inner vars): 0 systems Notification: Performance of Backend phase and start with SimCode phase: time 0.007116/1.043, allocations: 3.667 MB / 1.207 GB, free: 9.711 MB / 0.9669 GB Notification: Performance of simCode: created initialization part: time 0.00467/1.047, allocations: 2.67 MB / 1.21 GB, free: 6.977 MB / 0.9669 GB Notification: Performance of simCode: created event and clocks part: time 7.043e-06/1.047, allocations: 0 / 1.21 GB, free: 6.977 MB / 0.9669 GB Notification: Performance of simCode: created simulation system equations: time 0.001736/1.049, allocations: 1.116 MB / 1.211 GB, free: 5.824 MB / 0.9669 GB Notification: Performance of simCode: created of all other equations (e.g. parameter, nominal, assert, etc): time 0.009734/1.059, allocations: 1.415 MB / 1.212 GB, free: 4.438 MB / 0.9669 GB Notification: Performance of simCode: created linear, non-linear and system jacobian parts: time 0.009079/1.068, allocations: 6.384 MB / 1.218 GB, free: 13.94 MB / 0.9825 GB Notification: Performance of simCode: some other stuff during SimCode phase: time 0.001659/1.07, allocations: 1.718 MB / 1.22 GB, free: 12.19 MB / 0.9825 GB Notification: Performance of simCode: alias equations: time 0.003798/1.074, allocations: 0.7063 MB / 1.221 GB, free: 11.51 MB / 0.9825 GB Notification: Performance of simCode: all other stuff during SimCode phase: time 0.0008062/1.074, allocations: 247.3 kB / 1.221 GB, free: 11.27 MB / 0.9825 GB Notification: Performance of SimCode: time 1.803e-06/1.074, allocations: 0 / 1.221 GB, free: 11.27 MB / 0.9825 GB Notification: Performance of Templates: time 0.5649/1.639, allocations: 63.73 MB / 1.283 GB, free: 256.8 MB / 0.9981 GB make -j1 -f Buildings_9_Buildings.Fluid.Geothermal.BuriedPipes.Examples.TwoPipesConduit.makefile (rm -f Buildings_9_Buildings.Fluid.Geothermal.BuriedPipes.Examples.TwoPipesConduit.pipe ; mkfifo Buildings_9_Buildings.Fluid.Geothermal.BuriedPipes.Examples.TwoPipesConduit.pipe ; head -c 1048576 < Buildings_9_Buildings.Fluid.Geothermal.BuriedPipes.Examples.TwoPipesConduit.pipe >> ../files/Buildings_9_Buildings.Fluid.Geothermal.BuriedPipes.Examples.TwoPipesConduit.sim & ./Buildings_9_Buildings.Fluid.Geothermal.BuriedPipes.Examples.TwoPipesConduit -abortSlowSimulation -alarm=480 -emit_protected -lv LOG_STATS > Buildings_9_Buildings.Fluid.Geothermal.BuriedPipes.Examples.TwoPipesConduit.pipe 2>&1) diffSimulationResults("Buildings_9_Buildings.Fluid.Geothermal.BuriedPipes.Examples.TwoPipesConduit_res.mat","/mnt/ReferenceFiles/Buildings/csv/maint_9.1.x/Buildings_Fluid_Geothermal_BuriedPipes_Examples_TwoPipesConduit.csv","/var/lib/jenkins/ws/OpenModelicaLibraryTestingWork/OpenModelicaLibraryTesting/files/Buildings_9_Buildings.Fluid.Geothermal.BuriedPipes.Examples.TwoPipesConduit.diff",relTol=0.003,relTolDiffMinMax=0.003,rangeDelta=0.001) Reference file matches