Running: ./testmodel.py --libraries=/home/hudson/saved_omc/libraries/.openmodelica/libraries --ompython_omhome=/usr ModelicaTest_3.2.3_ModelicaTest.Fluid.Dissipation.Verifications.HeatTransfer.Channel.kc_evenGapLaminar.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 3.2.3+maint.om/package.mo", uses=false)
loadFile("/home/hudson/saved_omc/libraries/.openmodelica/libraries/ModelicaTest 3.2.3+maint.om/package.mo", uses=false)
Using package ModelicaTest with version 3.2.3 (/home/hudson/saved_omc/libraries/.openmodelica/libraries/ModelicaTest 3.2.3+maint.om/package.mo)
Using package Modelica with version 3.2.3 (/home/hudson/saved_omc/libraries/.openmodelica/libraries/Modelica 3.2.3+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: "" <> buildModelFMU(ModelicaTest.Fluid.Dissipation.Verifications.HeatTransfer.Channel.kc_evenGapLaminar,fileNamePrefix="ModelicaTest_3_2_3_ModelicaTest_Fluid_Dissipation_Verifications_HeatTransfer_Channel_kc_evenGapLaminar",fmuType="me",version="2.0",platforms={"static"})
"" <> buildModelFMU(ModelicaTest.Fluid.Dissipation.Verifications.HeatTransfer.Channel.kc_evenGapLaminar,fileNamePrefix="ModelicaTest_3_2_3_ModelicaTest_Fluid_Dissipation_Verifications_HeatTransfer_Channel_kc_evenGapLaminar",fmuType="me",version="2.0",platforms={"static"})
Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/ModelicaServices 4.0.0+maint.om/package.mo): time 0.001625/0.001625, allocations: 106.2 kB / 16.41 MB, free: 6.508 MB / 14.72 MB
Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Complex 4.0.0+maint.om/package.mo): time 0.001765/0.001765, allocations: 194.2 kB / 17.34 MB, free: 5.738 MB / 14.72 MB
Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Modelica 3.2.3+maint.om/package.mo): time 1.381/1.381, allocations: 205.1 MB / 223.2 MB, free: 12.23 MB / 190.1 MB
Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/ModelicaTest 3.2.3+maint.om/package.mo): time 0.2257/0.2257, allocations: 43.52 MB / 314.1 MB, free: 452 kB / 254.1 MB
Notification: Modelica requested package Complex of version 3.2.3. Complex 4.0.0 is used instead which states that it is fully compatible without conversion script needed.
Notification: Modelica requested package ModelicaServices of version 3.2.3. ModelicaServices 4.0.0 is used instead which states that it is fully compatible without conversion script needed.
Notification: Performance of FrontEnd - loaded program: time 0.00215/0.00215, allocations: 71.89 kB / 441.3 MB, free: 6.113 MB / 318.1 MB
Notification: Performance of FrontEnd - Absyn->SCode: time 0.1187/0.1209, allocations: 57.79 MB / 499.1 MB, free: 12.25 MB / 382.1 MB
Notification: Performance of NFInst.instantiate(ModelicaTest.Fluid.Dissipation.Verifications.HeatTransfer.Channel.kc_evenGapLaminar): time 0.003725/0.1247, allocations: 1.941 MB / 0.4893 GB, free: 10.29 MB / 382.1 MB
Notification: Performance of NFInst.instExpressions: time 0.002065/0.1268, allocations: 1.177 MB / 0.4905 GB, free: 9.109 MB / 382.1 MB
Notification: Performance of NFInst.updateImplicitVariability: time 0.0001164/0.1269, allocations: 4 kB / 0.4905 GB, free: 9.105 MB / 382.1 MB
Notification: Performance of NFTyping.typeComponents: time 0.0003363/0.1273, allocations: 67.58 kB / 0.4905 GB, free: 9.039 MB / 382.1 MB
Notification: Performance of NFTyping.typeBindings: time 0.000285/0.1276, allocations: 103.5 kB / 0.4906 GB, free: 8.938 MB / 382.1 MB
Notification: Performance of NFTyping.typeClassSections: time 0.0005423/0.1282, allocations: 155.4 kB / 0.4908 GB, free: 8.785 MB / 382.1 MB
Notification: Performance of NFFlatten.flatten: time 0.0005756/0.1287, allocations: 477.5 kB / 0.4912 GB, free: 8.316 MB / 382.1 MB
Notification: Performance of NFFlatten.resolveConnections: time 0.0001031/0.1289, allocations: 64.94 kB / 0.4913 GB, free: 8.25 MB / 382.1 MB
Notification: Performance of NFEvalConstants.evaluate: time 0.0001644/0.129, allocations: 155.2 kB / 0.4915 GB, free: 8.098 MB / 382.1 MB
Notification: Performance of NFSimplifyModel.simplify: time 0.0002838/0.1293, allocations: 195 kB / 0.4916 GB, free: 7.906 MB / 382.1 MB
Notification: Performance of NFPackage.collectConstants: time 3.909e-05/0.1294, allocations: 15.94 kB / 0.4917 GB, free: 7.891 MB / 382.1 MB
Notification: Performance of NFFlatten.collectFunctions: time 0.0005077/0.1299, allocations: 271.6 kB / 0.4919 GB, free: 7.625 MB / 382.1 MB
Notification: Performance of NFScalarize.scalarize: time 0.000129/0.13, allocations: 99.52 kB / 0.492 GB, free: 7.527 MB / 382.1 MB
Notification: Performance of NFVerifyModel.verify: time 0.0001952/0.1302, allocations: 186.6 kB / 0.4922 GB, free: 7.344 MB / 382.1 MB
Notification: Performance of NFConvertDAE.convert: time 0.000751/0.131, allocations: 0.5639 MB / 0.4927 GB, free: 6.777 MB / 382.1 MB
Notification: Performance of FrontEnd - DAE generated: time 4.588e-06/0.131, allocations: 0 / 0.4927 GB, free: 6.777 MB / 382.1 MB
Notification: Performance of FrontEnd: time 1.863e-06/0.131, allocations: 4 kB / 0.4927 GB, free: 6.773 MB / 382.1 MB
Notification: Performance of Transformations before backend: time 7.604e-06/0.131, allocations: 0 / 0.4927 GB, free: 6.773 MB / 382.1 MB
Notification: Model statistics after passing the front-end and creating the data structures used by the back-end:
 * Number of equations: 137
 * Number of variables: 137
Notification: Performance of Generate backend data structure: time 0.001134/0.1322, allocations: 0.7366 MB / 0.4935 GB, free: 5.984 MB / 382.1 MB
Notification: Performance of prepare preOptimizeDAE: time 4.766e-05/0.1322, allocations: 12.03 kB / 0.4935 GB, free: 5.973 MB / 382.1 MB
Notification: Performance of preOpt introduceOutputAliases (simulation): time 0.000113/0.1323, allocations: 94.7 kB / 0.4936 GB, free: 5.871 MB / 382.1 MB
Notification: Performance of preOpt normalInlineFunction (simulation): time 9.307e-05/0.1324, allocations: 52.61 kB / 0.4936 GB, free: 5.82 MB / 382.1 MB
Notification: Performance of preOpt evaluateParameters (simulation): time 0.0003943/0.1328, allocations: 295.6 kB / 0.4939 GB, free: 5.492 MB / 382.1 MB
Notification: Performance of preOpt simplifyIfEquations (simulation): time 4.196e-05/0.1329, allocations: 45.61 kB / 0.4939 GB, free: 5.449 MB / 382.1 MB
Notification: Performance of preOpt expandDerOperator (simulation): time 8.35e-05/0.133, allocations: 51.94 kB / 0.494 GB, free: 5.398 MB / 382.1 MB
Notification: Performance of preOpt clockPartitioning (simulation): time 0.0009391/0.1339, allocations: 0.6311 MB / 0.4946 GB, free: 4.758 MB / 382.1 MB
Notification: Performance of preOpt findStateOrder (simulation): time 1.59e-05/0.134, allocations: 0 / 0.4946 GB, free: 4.758 MB / 382.1 MB
Notification: Performance of preOpt replaceEdgeChange (simulation): time 5.166e-05/0.134, allocations: 19.98 kB / 0.4946 GB, free: 4.738 MB / 382.1 MB
Notification: Performance of preOpt inlineArrayEqn (simulation): time 5.449e-05/0.1341, allocations: 41.3 kB / 0.4947 GB, free: 4.699 MB / 382.1 MB
Notification: Performance of preOpt removeEqualRHS (simulation): time 0.0009004/0.135, allocations: 0.5008 MB / 0.4952 GB, free: 4.199 MB / 382.1 MB
Notification: Performance of preOpt removeSimpleEquations (simulation): time 0.002555/0.1375, allocations: 1.415 MB / 0.4965 GB, free: 2.73 MB / 382.1 MB
Notification: Performance of preOpt comSubExp (simulation): time 0.0007764/0.1383, allocations: 453.9 kB / 0.497 GB, free: 2.277 MB / 382.1 MB
Notification: Performance of preOpt resolveLoops (simulation): time 0.0002446/0.1386, allocations: 136.8 kB / 0.4971 GB, free: 2.141 MB / 382.1 MB
Notification: Performance of preOpt evalFunc (simulation): time 6.955e-05/0.1387, allocations: 19.92 kB / 0.4971 GB, free: 2.121 MB / 382.1 MB
Notification: Performance of preOpt encapsulateWhenConditions (simulation): time 3.212e-05/0.1387, allocations: 34.55 kB / 0.4972 GB, free: 2.078 MB / 382.1 MB
Notification: Performance of pre-optimization done (n=25): time 3.166e-06/0.1387, allocations: 0 / 0.4972 GB, free: 2.078 MB / 382.1 MB
Notification: Performance of matching and sorting (n=25): time 0.001007/0.1397, allocations: 0.4971 MB / 0.4976 GB, free: 1.574 MB / 382.1 MB
Notification: Performance of inlineWhenForInitialization (initialization): time 4.911e-05/0.1398, allocations: 55.41 kB / 0.4977 GB, free: 1.508 MB / 382.1 MB
Notification: Performance of selectInitializationVariablesDAE (initialization): time 0.0006761/0.1405, allocations: 0.5485 MB / 0.4982 GB, free: 0.9492 MB / 382.1 MB
Notification: Performance of collectPreVariables (initialization): time 3.644e-05/0.1405, allocations: 33.7 kB / 0.4983 GB, free: 0.9102 MB / 382.1 MB
Notification: Performance of collectInitialEqns (initialization): time 0.0002271/0.1408, allocations: 224.3 kB / 0.4985 GB, free: 0.6836 MB / 382.1 MB
Notification: Performance of collectInitialBindings (initialization): time 9.605e-05/0.1409, allocations: 91.27 kB / 0.4986 GB, free: 0.5938 MB / 382.1 MB
Notification: Performance of simplifyInitialFunctions (initialization): time 0.000154/0.141, allocations: 93.95 kB / 0.4987 GB, free: 0.4922 MB / 382.1 MB
Notification: Performance of setup shared object (initialization): time 0.0001864/0.1412, allocations: 354.7 kB / 0.499 GB, free: 140 kB / 382.1 MB
Notification: Performance of preBalanceInitialSystem (initialization): time 0.0002919/0.1415, allocations: 164.2 kB / 0.4991 GB, free: 15.97 MB / 398.1 MB
Notification: Performance of partitionIndependentBlocks (initialization): time 0.0003725/0.1419, allocations: 256.7 kB / 0.4994 GB, free: 15.68 MB / 398.1 MB
Notification: Performance of analyzeInitialSystem (initialization): time 0.00391/0.1458, allocations: 1.053 MB / 0.5004 GB, free: 14.59 MB / 398.1 MB
Notification: Performance of solveInitialSystemEqSystem (initialization): time 6.302e-06/0.1459, allocations: 0 / 0.5004 GB, free: 14.59 MB / 398.1 MB
Notification: Performance of matching and sorting (n=41) (initialization): time 0.0009844/0.1469, allocations: 0.5047 MB / 0.5009 GB, free: 14.07 MB / 398.1 MB
Notification: Performance of prepare postOptimizeDAE: time 2.501e-05/0.1469, allocations: 10.66 kB / 0.5009 GB, free: 14.07 MB / 398.1 MB
Notification: Performance of postOpt simplifyComplexFunction (initialization): time 9.448e-05/0.147, allocations: 39.98 kB / 0.501 GB, free: 14.03 MB / 398.1 MB
Notification: Performance of postOpt tearingSystem (initialization): time 2.604e-05/0.147, allocations: 8 kB / 0.501 GB, free: 14.02 MB / 398.1 MB
Notification: Performance of postOpt solveSimpleEquations (initialization): time 0.0002038/0.1472, allocations: 43.91 kB / 0.501 GB, free: 13.98 MB / 398.1 MB
Notification: Performance of postOpt calculateStrongComponentJacobians (initialization): time 1.221e-05/0.1473, allocations: 4 kB / 0.501 GB, free: 13.97 MB / 398.1 MB
Notification: Performance of postOpt simplifyAllExpressions (initialization): time 0.0002917/0.1476, allocations: 59.45 kB / 0.5011 GB, free: 13.91 MB / 398.1 MB
Notification: Performance of postOpt collapseArrayExpressions (initialization): time 5.601e-05/0.1476, allocations: 23.98 kB / 0.5011 GB, free: 13.89 MB / 398.1 MB
Warning: Assuming fixed start value for the following 1 variables:
         dimlesslength:VARIABLE(start = 0.01 unit = "m" fixed = true )  type: Real
Notification: Model statistics after passing the back-end for initialization:
 * Number of independent subsystems: 14
 * Number of states: 0 ()
 * Number of discrete variables: 12 (m_flow_IN_con_4[3].target,m_flow_IN_con_4[2].target,m_flow_IN_con_4[1].target,m_flow_IN_con_3[3].target,m_flow_IN_con_3[2].target,m_flow_IN_con_3[1].target,m_flow_IN_con_2[3].target,m_flow_IN_con_2[2].target,m_flow_IN_con_2[1].target,m_flow_IN_con_1[3].target,m_flow_IN_con_1[2].target,m_flow_IN_con_1[1].target)
 * Number of discrete states: 0 ()
 * Number of clocked states: 0 ()
 * Top-level inputs: 0
Notification: Strong component statistics for initialization (41):
 * Single equations (assignments): 29
 * Array equations: 0
 * Algorithm blocks: 0
 * Record equations: 12
 * 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 0.0004159/0.148, allocations: 233.8 kB / 0.5013 GB, free: 13.65 MB / 398.1 MB
Notification: Performance of postOpt lateInlineFunction (simulation): time 8.417e-05/0.1481, allocations: 43.72 kB / 0.5014 GB, free: 13.61 MB / 398.1 MB
Notification: Performance of postOpt wrapFunctionCalls (simulation): time 0.001054/0.1492, allocations: 0.5323 MB / 0.5019 GB, free: 13.07 MB / 398.1 MB
Notification: Performance of postOpt inlineArrayEqn (simulation): time 1.352e-05/0.1492, allocations: 11.94 kB / 0.5019 GB, free: 13.06 MB / 398.1 MB
Notification: Performance of postOpt constantLinearSystem (simulation): time 5.721e-06/0.1492, allocations: 0 / 0.5019 GB, free: 13.06 MB / 398.1 MB
Notification: Performance of postOpt simplifysemiLinear (simulation): time 7.093e-06/0.1492, allocations: 3.984 kB / 0.5019 GB, free: 13.06 MB / 398.1 MB
Notification: Performance of postOpt removeSimpleEquations (simulation): time 0.0006688/0.1499, allocations: 433.1 kB / 0.5023 GB, free: 12.59 MB / 398.1 MB
Notification: Performance of postOpt simplifyComplexFunction (simulation): time 6.9e-05/0.15, allocations: 39.98 kB / 0.5023 GB, free: 12.55 MB / 398.1 MB
Notification: Performance of postOpt solveSimpleEquations (simulation): time 0.0001597/0.1502, allocations: 31.92 kB / 0.5024 GB, free: 12.52 MB / 398.1 MB
Notification: Performance of postOpt tearingSystem (simulation): time 4.158e-06/0.1502, allocations: 0 / 0.5024 GB, free: 12.52 MB / 398.1 MB
Notification: Performance of postOpt inputDerivativesUsed (simulation): time 3.836e-05/0.1502, allocations: 12 kB / 0.5024 GB, free: 12.51 MB / 398.1 MB
Notification: Performance of postOpt calculateStrongComponentJacobians (simulation): time 3.106e-06/0.1502, allocations: 0 / 0.5024 GB, free: 12.51 MB / 398.1 MB
Notification: Performance of postOpt calculateStateSetsJacobians (simulation): time 1.022e-06/0.1502, allocations: 0 / 0.5024 GB, free: 12.51 MB / 398.1 MB
Notification: Performance of postOpt symbolicJacobian (simulation): time 0.001095/0.1513, allocations: 0.7147 MB / 0.5031 GB, free: 11.78 MB / 398.1 MB
Notification: Performance of postOpt removeConstants (simulation): time 0.0001433/0.1515, allocations: 128.7 kB / 0.5032 GB, free: 11.63 MB / 398.1 MB
Notification: Performance of postOpt simplifyTimeIndepFuncCalls (simulation): time 6.674e-05/0.1516, allocations: 12.06 kB / 0.5032 GB, free: 11.62 MB / 398.1 MB
Notification: Performance of postOpt simplifyAllExpressions (simulation): time 0.0001797/0.1518, allocations: 11.98 kB / 0.5032 GB, free: 11.61 MB / 398.1 MB
Notification: Performance of postOpt findZeroCrossings (simulation): time 6.912e-05/0.1518, allocations: 15.98 kB / 0.5032 GB, free: 11.59 MB / 398.1 MB
Notification: Performance of postOpt collapseArrayExpressions (simulation): time 3.994e-05/0.1519, allocations: 19.98 kB / 0.5033 GB, free: 11.57 MB / 398.1 MB
Notification: Performance of sorting global known variables: time 0.0004769/0.1524, allocations: 407 kB / 0.5037 GB, free: 11.18 MB / 398.1 MB
Notification: Performance of sort global known variables: time 1.963e-06/0.1524, allocations: 0 / 0.5037 GB, free: 11.18 MB / 398.1 MB
Notification: Performance of remove unused functions: time 0.000535/0.1529, allocations: 143.8 kB / 0.5038 GB, free: 11.04 MB / 398.1 MB
Notification: Model statistics after passing the back-end for simulation:
 * Number of independent subsystems: 1
 * Number of states: 1 (dimlesslength)
 * 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 (28):
 * Single equations (assignments): 16
 * Array equations: 0
 * Algorithm blocks: 0
 * Record equations: 12
 * 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 0.001666/0.1546, allocations: 1.317 MB / 0.5051 GB, free: 9.695 MB / 398.1 MB
Notification: Performance of simCode: created initialization part: time 0.0009285/0.1555, allocations: 0.6796 MB / 0.5057 GB, free: 8.941 MB / 398.1 MB
Notification: Performance of simCode: created event and clocks part: time 2.665e-06/0.1555, allocations: 0 / 0.5057 GB, free: 8.941 MB / 398.1 MB
Notification: Performance of simCode: created simulation system equations: time 0.0004941/0.156, allocations: 484.2 kB / 0.5062 GB, free: 8.395 MB / 398.1 MB
Notification: Performance of simCode: created of all other equations (e.g. parameter, nominal, assert, etc): time 0.0006045/0.1567, allocations: 94.66 kB / 0.5063 GB, free: 8.301 MB / 398.1 MB
Notification: Performance of simCode: created linear, non-linear and system jacobian parts: time 0.007582/0.1642, allocations: 5.332 MB / 0.5115 GB, free: 2.805 MB / 398.1 MB
Notification: Performance of simCode: some other stuff during SimCode phase: time 0.0005886/0.1649, allocations: 0.8858 MB / 0.5124 GB, free: 1.895 MB / 398.1 MB
Notification: Performance of simCode: alias equations: time 0.0003317/0.1652, allocations: 112.2 kB / 0.5125 GB, free: 1.781 MB / 398.1 MB
Notification: Performance of simCode: all other stuff during SimCode phase: time 0.0002073/0.1654, allocations: 143.2 kB / 0.5126 GB, free: 1.645 MB / 398.1 MB
Notification: Performance of SimCode: time 1.192e-06/0.1655, allocations: 0 / 0.5126 GB, free: 1.645 MB / 398.1 MB
Notification: Performance of buildModelFMU: Generate the FMI files: time 0.04204/0.2075, allocations: 12.79 MB / 0.5251 GB, free: 4.848 MB / 414.1 MB
Notification: Performance of buildModelFMU: Generate platform static: time 8.588/8.796, allocations: 12.11 kB / 0.5251 GB, free: 4.836 MB / 414.1 MB
(rm -f ModelicaTest_3.2.3_ModelicaTest.Fluid.Dissipation.Verifications.HeatTransfer.Channel.kc_evenGapLaminar.pipe ; mkfifo ModelicaTest_3.2.3_ModelicaTest.Fluid.Dissipation.Verifications.HeatTransfer.Channel.kc_evenGapLaminar.pipe ; head -c 1048576 < ModelicaTest_3.2.3_ModelicaTest.Fluid.Dissipation.Verifications.HeatTransfer.Channel.kc_evenGapLaminar.pipe >> ../files/ModelicaTest_3.2.3_ModelicaTest.Fluid.Dissipation.Verifications.HeatTransfer.Channel.kc_evenGapLaminar.sim & /home/hudson/saved_omc/OMSimulator/install/bin/OMSimulator -r=ModelicaTest_3.2.3_ModelicaTest.Fluid.Dissipation.Verifications.HeatTransfer.Channel.kc_evenGapLaminar_res.mat --tempDir=temp_ModelicaTest_3_2_3_ModelicaTest_Fluid_Dissipation_Verifications_HeatTransfer_Channel_kc_evenGapLaminar_fmu --startTime=0 --stopTime=1.01 --timeout=50 --tolerance=1e-06 ModelicaTest_3_2_3_ModelicaTest_Fluid_Dissipation_Verifications_HeatTransfer_Channel_kc_evenGapLaminar.fmu > ModelicaTest_3.2.3_ModelicaTest.Fluid.Dissipation.Verifications.HeatTransfer.Channel.kc_evenGapLaminar.pipe 2>&1)
diffSimulationResults("ModelicaTest_3.2.3_ModelicaTest.Fluid.Dissipation.Verifications.HeatTransfer.Channel.kc_evenGapLaminar_res.mat","/var/lib/jenkins1/ws/OpenModelicaLibraryTestingWork/Reference-modelica.org/ReferenceResults/MAP-LIB_ReferenceResults/v3.2.3+build.4/ModelicaTest/Fluid/Dissipation/Verifications/HeatTransfer/Channel/kc_evenGapLaminar/kc_evenGapLaminar.csv","/var/lib/jenkins1/ws/OpenModelicaLibraryTestingWork/OpenModelicaLibraryTesting/files/ModelicaTest_3.2.3_ModelicaTest.Fluid.Dissipation.Verifications.HeatTransfer.Channel.kc_evenGapLaminar.diff",relTol=0.003,relTolDiffMinMax=0.003,rangeDelta=0.001)
Reference file matches