Running: ./testmodel.py --libraries=/home/hudson/saved_omc/libraries/.openmodelica/libraries --ompython_omhome=/usr Modelica_4.0.0_Modelica.Mechanics.MultiBody.Examples.Loops.Engine1a.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)
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: "" <> buildModelFMU(Modelica.Mechanics.MultiBody.Examples.Loops.Engine1a,fileNamePrefix="Modelica_4_0_0_Modelica_Mechanics_MultiBody_Examples_Loops_Engine1a",fmuType="me",version="2.0",platforms={"static"})
"" <> buildModelFMU(Modelica.Mechanics.MultiBody.Examples.Loops.Engine1a,fileNamePrefix="Modelica_4_0_0_Modelica_Mechanics_MultiBody_Examples_Loops_Engine1a",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 0.001519/0.001519, allocations: 105.9 kB / 17.06 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 0.001579/0.001579, allocations: 189.4 kB / 18 MB, free: 5.09 MB / 14.72 MB
Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Modelica 4.0.0+maint.om/package.mo): time 1.355/1.355, allocations: 222.9 MB / 241.7 MB, free: 15.17 MB / 206.1 MB
Notification: Performance of FrontEnd - loaded program: time 0.001429/0.001429, allocations: 43.92 kB / 350.8 MB, free: 3.746 MB / 286.1 MB
Notification: Performance of FrontEnd - Absyn->SCode: time 0.2527/0.2542, allocations: 49.44 MB / 400.3 MB, free: 8.414 MB / 318.1 MB
Notification: Performance of NFInst.instantiate(Modelica.Mechanics.MultiBody.Examples.Loops.Engine1a): time 0.02242/0.2766, allocations: 19.44 MB / 419.7 MB, free: 5.316 MB / 334.1 MB
Notification: Performance of NFInst.instExpressions: time 0.01302/0.2897, allocations: 5.966 MB / 425.7 MB, free: 15.33 MB / 350.1 MB
Notification: Performance of NFInst.updateImplicitVariability: time 0.00364/0.2934, allocations: 159.4 kB / 425.8 MB, free: 15.18 MB / 350.1 MB
Notification: Performance of NFTyping.typeComponents: time 0.01129/0.3047, allocations: 5.849 MB / 431.7 MB, free: 9.309 MB / 350.1 MB
Notification: Performance of NFTyping.typeBindings: time 0.009289/0.3141, allocations: 3.336 MB / 435 MB, free: 5.961 MB / 350.1 MB
Notification: Performance of NFTyping.typeClassSections: time 0.003802/0.3179, allocations: 1.564 MB / 436.6 MB, free: 4.395 MB / 350.1 MB
Notification: Performance of NFFlatten.flatten: time 0.0184/0.3363, allocations: 12.37 MB / 448.9 MB, free: 8.008 MB / 366.1 MB
Notification: Performance of NFFlatten.resolveConnections: time 0.01024/0.3466, allocations: 7.654 MB / 456.6 MB, free: 272 kB / 366.1 MB
Notification: Performance of NFEvalConstants.evaluate: time 0.007006/0.3537, allocations: 3.548 MB / 460.1 MB, free: 12.71 MB / 382.1 MB
Notification: Performance of NFSimplifyModel.simplify: time 0.00815/0.3619, allocations: 4.74 MB / 464.9 MB, free: 7.953 MB / 382.1 MB
Notification: Performance of NFPackage.collectConstants: time 0.002485/0.3644, allocations: 0.7188 MB / 465.6 MB, free: 7.234 MB / 382.1 MB
Notification: Performance of NFFlatten.collectFunctions: time 0.004507/0.3689, allocations: 1.67 MB / 467.3 MB, free: 5.562 MB / 382.1 MB
Notification: Performance of NFScalarize.scalarize: time 0.005983/0.3749, allocations: 4.185 MB / 471.5 MB, free: 1.367 MB / 382.1 MB
Notification: Performance of NFVerifyModel.verify: time 0.009078/0.384, allocations: 4.76 MB / 476.2 MB, free: 12.58 MB / 398.1 MB
Notification: Performance of NFConvertDAE.convert: time 0.01997/0.404, allocations: 14.41 MB / 490.6 MB, free: 14.12 MB / 414.1 MB
Notification: Performance of FrontEnd - DAE generated: time 8.516e-06/0.4041, allocations: 0 / 490.6 MB, free: 14.12 MB / 414.1 MB
Notification: Performance of FrontEnd: time 2.134e-06/0.4041, allocations: 0 / 490.6 MB, free: 14.12 MB / 414.1 MB
Notification: Performance of Transformations before backend: time 0.0005134/0.4046, allocations: 0 / 490.6 MB, free: 14.12 MB / 414.1 MB
Notification: Model statistics after passing the front-end and creating the data structures used by the back-end:
 * Number of equations: 2386
 * Number of variables: 2386
Notification: Performance of Generate backend data structure: time 0.03204/0.4366, allocations: 10.58 MB / 0.4895 GB, free: 3.43 MB / 414.1 MB
Notification: Performance of prepare preOptimizeDAE: time 5.286e-05/0.4367, allocations: 12.03 kB / 0.4895 GB, free: 3.418 MB / 414.1 MB
Notification: Performance of preOpt introduceOutputAliases (simulation): time 0.003173/0.4399, allocations: 1.144 MB / 0.4906 GB, free: 2.262 MB / 414.1 MB
Notification: Performance of preOpt normalInlineFunction (simulation): time 0.3098/0.7497, allocations: 24.3 MB / 0.5143 GB, free: 9.926 MB / 446.1 MB
Notification: Performance of preOpt evaluateParameters (simulation): time 0.02212/0.7719, allocations: 9.804 MB / 0.5239 GB, free: 32 kB / 446.1 MB
Notification: Performance of preOpt simplifyIfEquations (simulation): time 0.0004795/0.7724, allocations: 431.2 kB / 0.5243 GB, free: 15.61 MB / 462.1 MB
Notification: Performance of preOpt expandDerOperator (simulation): time 0.002219/0.7746, allocations: 0.5816 MB / 0.5249 GB, free: 15.03 MB / 462.1 MB
Notification: Performance of preOpt clockPartitioning (simulation): time 0.41/1.185, allocations: 16.17 MB / 0.5407 GB, free: 119.9 MB / 462.1 MB
Notification: Performance of preOpt findStateOrder (simulation): time 0.0003897/1.185, allocations: 100.4 kB / 0.5408 GB, free: 119.9 MB / 462.1 MB
Notification: Performance of preOpt replaceEdgeChange (simulation): time 0.001023/1.186, allocations: 265.3 kB / 0.541 GB, free: 119.9 MB / 462.1 MB
Notification: Performance of preOpt inlineArrayEqn (simulation): time 0.004197/1.19, allocations: 2.766 MB / 0.5437 GB, free: 119.5 MB / 462.1 MB
Notification: Performance of preOpt removeEqualRHS (simulation): time 0.02461/1.215, allocations: 12.86 MB / 0.5563 GB, free: 114.2 MB / 462.1 MB
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 0.06713/1.282, allocations: 66.24 MB / 0.621 GB, free: 48.77 MB / 462.1 MB
Notification: Performance of preOpt comSubExp (simulation): time 0.01708/1.299, allocations: 7.604 MB / 0.6284 GB, free: 41.03 MB / 462.1 MB
Notification: Performance of preOpt resolveLoops (simulation): time 0.004416/1.304, allocations: 4.202 MB / 0.6325 GB, free: 36.81 MB / 462.1 MB
Notification: Performance of preOpt evalFunc (simulation): time 0.01472/1.319, allocations: 11.7 MB / 0.6439 GB, free: 25.05 MB / 462.1 MB
Notification: Performance of preOpt encapsulateWhenConditions (simulation): time 4.119e-05/1.319, allocations: 68.5 kB / 0.644 GB, free: 24.98 MB / 462.1 MB
Notification: Performance of pre-optimization done (n=280): time 5.7e-06/1.319, allocations: 4 kB / 0.644 GB, free: 24.98 MB / 462.1 MB
Notification: Performance of matching and sorting (n=339): time 0.1681/1.487, allocations: 47.8 MB / 0.6907 GB, free: 9.609 MB / 494.1 MB
Notification: Performance of inlineWhenForInitialization (initialization): time 0.0002549/1.487, allocations: 406 kB / 0.691 GB, free: 9.125 MB / 494.1 MB
Notification: Performance of selectInitializationVariablesDAE (initialization): time 0.01177/1.499, allocations: 7.167 MB / 0.698 GB, free: 2.082 MB / 494.1 MB
Notification: Performance of collectPreVariables (initialization): time 0.000872/1.5, allocations: 77.7 kB / 0.6981 GB, free: 2 MB / 494.1 MB
Notification: Performance of collectInitialEqns (initialization): time 0.004784/1.505, allocations: 5.344 MB / 0.7033 GB, free: 12.89 MB / 0.4982 GB
Notification: Performance of collectInitialBindings (initialization): time 0.001942/1.506, allocations: 1.31 MB / 0.7046 GB, free: 11.57 MB / 0.4982 GB
Notification: Performance of simplifyInitialFunctions (initialization): time 0.003088/1.51, allocations: 1.655 MB / 0.7062 GB, free: 9.902 MB / 0.4982 GB
Notification: Performance of setup shared object (initialization): time 0.000134/1.51, allocations: 308.9 kB / 0.7065 GB, free: 9.602 MB / 0.4982 GB
Notification: Performance of preBalanceInitialSystem (initialization): time 0.006221/1.516, allocations: 3.959 MB / 0.7104 GB, free: 5.633 MB / 0.4982 GB
Notification: Performance of partitionIndependentBlocks (initialization): time 0.01034/1.526, allocations: 8.587 MB / 0.7188 GB, free: 10.76 MB / 0.5138 GB
Notification: Performance of analyzeInitialSystem (initialization): time 0.01823/1.545, allocations: 13.48 MB / 0.7319 GB, free: 11 MB / 0.5294 GB
Notification: Performance of solveInitialSystemEqSystem (initialization): time 0.0001359/1.545, allocations: 48 kB / 0.732 GB, free: 10.95 MB / 0.5294 GB
Notification: Performance of matching and sorting (n=1070) (initialization): time 0.2477/1.792, allocations: 17.2 MB / 0.7488 GB, free: 178.3 MB / 0.5294 GB
Notification: Performance of prepare postOptimizeDAE: time 9.817e-05/1.793, allocations: 74.25 kB / 0.7489 GB, free: 178.3 MB / 0.5294 GB
Notification: Performance of postOpt simplifyComplexFunction (initialization): time 0.0001635/1.793, allocations: 159.6 kB / 0.749 GB, free: 178.3 MB / 0.5294 GB
Notification: Performance of postOpt tearingSystem (initialization): time 0.01648/1.809, allocations: 5.767 MB / 0.7546 GB, free: 178.3 MB / 0.5294 GB
Notification: Performance of postOpt solveSimpleEquations (initialization): time 0.005498/1.815, allocations: 1.75 MB / 0.7563 GB, free: 178.3 MB / 0.5294 GB
Notification: Performance of postOpt calculateStrongComponentJacobians (initialization): time 0.0352/1.85, allocations: 31.67 MB / 0.7873 GB, free: 159.8 MB / 0.5294 GB
Notification: Performance of postOpt simplifyAllExpressions (initialization): time 0.006923/1.857, allocations: 0.5261 MB / 0.7878 GB, free: 159.3 MB / 0.5294 GB
Notification: Performance of postOpt collapseArrayExpressions (initialization): time 0.001334/1.858, allocations: 472 kB / 0.7882 GB, free: 158.8 MB / 0.5294 GB
Notification: Model statistics after passing the back-end for initialization:
 * Number of independent subsystems: 727
 * Number of states: 0 ()
 * Number of discrete variables: 66 (cylinder.boxColor[3],cylinder.boxColor[2],cylinder.boxColor[1],b2.cylinderColor[3],b2.cylinderColor[2],b2.cylinderColor[1],b1.cylinderColor[3],b1.cylinderColor[2],b1.cylinderColor[1],cylPosition.color[3],cylPosition.color[2],cylPosition.color[1],mid.color[3],mid.color[2],mid.color[1],crank4.color[3],crank4.color[2],crank4.color[1],crank4.body.sphereColor[3],crank4.body.sphereColor[2],crank4.body.sphereColor[1],crank3.color[3],crank3.color[2],crank3.color[1],crank3.body.sphereColor[3],crank3.body.sphereColor[2],crank3.body.sphereColor[1],crank2.color[3],crank2.color[2],crank2.color[1],crank2.body.sphereColor[3],crank2.body.sphereColor[2],crank2.body.sphereColor[1],crank1.color[3],crank1.color[2],crank1.color[1],crank1.body.sphereColor[3],crank1.body.sphereColor[2],crank1.body.sphereColor[1],bearing.cylinderColor[3],bearing.cylinderColor[2],bearing.cylinderColor[1],connectingRod.color[3],connectingRod.color[2],connectingRod.color[1],connectingRod.body.sphereColor[3],connectingRod.body.sphereColor[2],connectingRod.body.sphereColor[1],piston.color[3],piston.color[2],piston.color[1],piston.body.sphereColor[3],piston.body.sphereColor[2],piston.body.sphereColor[1],world.gravityArrowColor[3],world.gravityArrowColor[2],world.gravityArrowColor[1],world.axisColor_x[3],world.axisColor_x[2],world.axisColor_x[1],world.groundColor[3],world.groundColor[2],world.groundColor[1],world.gravitySphereColor[3],world.gravitySphereColor[2],world.gravitySphereColor[1])
 * Number of discrete states: 0 ()
 * Number of clocked states: 0 ()
 * Top-level inputs: 0
Notification: Strong component statistics for initialization (934):
 * Single equations (assignments): 928
 * Array equations: 3
 * Algorithm blocks: 0
 * Record equations: 0
 * When equations: 0
 * If-equations: 0
 * Equation systems (not torn): 0
 * Torn equation systems: 3
 * Mixed (continuous/discrete) equation systems: 0
Notification: Torn system details for strict tearing set:
 * Linear torn systems (#iteration vars, #inner vars, density): 2 systems
   {(8,93,51.6%), (2,6,100.0%)}
 * Non-linear torn systems (#iteration vars, #inner vars): 1 system
   {(2,4)}
Notification: Performance of prepare postOptimizeDAE: time 0.00502/1.863, allocations: 3.457 MB / 0.7916 GB, free: 155.5 MB / 0.5294 GB
Notification: Performance of postOpt lateInlineFunction (simulation): time 0.001379/1.865, allocations: 0.691 MB / 0.7923 GB, free: 155.2 MB / 0.5294 GB
Notification: Performance of postOpt wrapFunctionCalls (simulation): time 0.0211/1.886, allocations: 11.48 MB / 0.8035 GB, free: 143.7 MB / 0.5294 GB
Notification: Performance of postOpt inlineArrayEqn (simulation): time 4.387e-05/1.886, allocations: 32 kB / 0.8035 GB, free: 143.7 MB / 0.5294 GB
Notification: Performance of postOpt constantLinearSystem (simulation): time 2.476e-05/1.886, allocations: 20 kB / 0.8035 GB, free: 143.6 MB / 0.5294 GB
Notification: Performance of postOpt simplifysemiLinear (simulation): time 4.281e-05/1.886, allocations: 15.94 kB / 0.8036 GB, free: 143.6 MB / 0.5294 GB
Notification: Performance of postOpt removeSimpleEquations (simulation): time 0.03757/1.924, allocations: 24.75 MB / 0.8277 GB, free: 118.6 MB / 0.5294 GB
Notification: Performance of postOpt simplifyComplexFunction (simulation): time 2.979e-05/1.924, allocations: 7.938 kB / 0.8277 GB, free: 118.6 MB / 0.5294 GB
Notification: Performance of postOpt solveSimpleEquations (simulation): time 0.001744/1.925, allocations: 415.4 kB / 0.8281 GB, free: 118.2 MB / 0.5294 GB
Notification: Performance of postOpt tearingSystem (simulation): time 0.01515/1.941, allocations: 5.38 MB / 0.8334 GB, free: 112.8 MB / 0.5294 GB
Notification: Performance of postOpt inputDerivativesUsed (simulation): time 0.0006499/1.941, allocations: 63.94 kB / 0.8334 GB, free: 112.8 MB / 0.5294 GB
Notification: Performance of postOpt calculateStrongComponentJacobians (simulation): time 0.03217/1.973, allocations: 30.35 MB / 0.8631 GB, free: 82.19 MB / 0.5294 GB
Notification: Performance of postOpt calculateStateSetsJacobians (simulation): time 8.105e-06/1.974, allocations: 15.94 kB / 0.8631 GB, free: 82.17 MB / 0.5294 GB
Notification: Performance of postOpt symbolicJacobian (simulation): time 0.02556/1.999, allocations: 16.52 MB / 0.8792 GB, free: 65.86 MB / 0.5294 GB
Notification: Performance of postOpt removeConstants (simulation): time 0.001874/2.001, allocations: 0.7168 MB / 0.8799 GB, free: 65.14 MB / 0.5294 GB
Notification: Performance of postOpt simplifyTimeIndepFuncCalls (simulation): time 0.001248/2.002, allocations: 64.06 kB / 0.88 GB, free: 65.08 MB / 0.5294 GB
Notification: Performance of postOpt simplifyAllExpressions (simulation): time 0.003197/2.005, allocations: 263.6 kB / 0.8802 GB, free: 64.82 MB / 0.5294 GB
Notification: Performance of postOpt findZeroCrossings (simulation): time 0.0008165/2.006, allocations: 242.6 kB / 0.8805 GB, free: 64.59 MB / 0.5294 GB
Notification: Performance of postOpt collapseArrayExpressions (simulation): time 0.0002588/2.007, allocations: 88 kB / 0.8806 GB, free: 64.5 MB / 0.5294 GB
Notification: Performance of sorting global known variables: time 0.006509/2.013, allocations: 4.62 MB / 0.8851 GB, free: 59.91 MB / 0.5294 GB
Notification: Performance of sort global known variables: time 2.375e-06/2.013, allocations: 0 / 0.8851 GB, free: 59.91 MB / 0.5294 GB
Notification: Performance of remove unused functions: time 0.008415/2.022, allocations: 1.974 MB / 0.887 GB, free: 57.95 MB / 0.5294 GB
Notification: Model statistics after passing the back-end for simulation:
 * Number of independent subsystems: 28
 * Number of states: 2 (inertia.phi,inertia.w)
 * 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 (214):
 * Single equations (assignments): 208
 * Array equations: 3
 * Algorithm blocks: 0
 * Record equations: 0
 * When equations: 0
 * If-equations: 0
 * Equation systems (not torn): 0
 * Torn equation systems: 3
 * Mixed (continuous/discrete) equation systems: 0
Notification: Torn system details for strict tearing set:
 * Linear torn systems (#iteration vars, #inner vars, density): 2 systems
   {(7,87,55.1%), (2,4,100.0%)}
 * Non-linear torn systems (#iteration vars, #inner vars): 1 system
   {(2,6)}
Notification: Performance of Backend phase and start with SimCode phase: time 0.02592/2.047, allocations: 17.22 MB / 0.9038 GB, free: 40.54 MB / 0.5294 GB
Notification: Performance of simCode: created initialization part: time 0.01473/2.062, allocations: 10.52 MB / 0.9141 GB, free: 29.97 MB / 0.5294 GB
Notification: Performance of simCode: created event and clocks part: time 1.238e-05/2.062, allocations: 4 kB / 0.9141 GB, free: 29.97 MB / 0.5294 GB
Notification: Performance of simCode: created simulation system equations: time 0.007145/2.069, allocations: 4.7 MB / 0.9187 GB, free: 25.21 MB / 0.5294 GB
Notification: Performance of simCode: created of all other equations (e.g. parameter, nominal, assert, etc): time 0.007264/2.077, allocations: 1.078 MB / 0.9197 GB, free: 24.14 MB / 0.5294 GB
Notification: Performance of simCode: created linear, non-linear and system jacobian parts: time 0.3574/2.434, allocations: 91.64 MB / 1.009 GB, free: 123.8 MB / 0.5294 GB
Notification: Performance of simCode: some other stuff during SimCode phase: time 0.006066/2.44, allocations: 5.526 MB / 1.015 GB, free: 118.3 MB / 0.5294 GB
Notification: Performance of simCode: alias equations: time 0.005676/2.446, allocations: 2.624 MB / 1.017 GB, free: 115.7 MB / 0.5294 GB
Notification: Performance of simCode: all other stuff during SimCode phase: time 0.004969/2.451, allocations: 3.741 MB / 1.021 GB, free: 111.9 MB / 0.5294 GB
Notification: Performance of SimCode: time 1.152e-06/2.451, allocations: 0 / 1.021 GB, free: 111.9 MB / 0.5294 GB
Notification: Performance of buildModelFMU: Generate the FMI files: time 0.4364/2.887, allocations: 157.5 MB / 1.175 GB, free: 172.3 MB / 0.545 GB
Notification: Performance of buildModelFMU: Generate platform static: time 39.14/42.02, allocations: 7.531 kB / 1.175 GB, free: 172.3 MB / 0.545 GB
(rm -f Modelica_4.0.0_Modelica.Mechanics.MultiBody.Examples.Loops.Engine1a.pipe ; mkfifo Modelica_4.0.0_Modelica.Mechanics.MultiBody.Examples.Loops.Engine1a.pipe ; head -c 1048576 < Modelica_4.0.0_Modelica.Mechanics.MultiBody.Examples.Loops.Engine1a.pipe >> ../files/Modelica_4.0.0_Modelica.Mechanics.MultiBody.Examples.Loops.Engine1a.sim & /home/hudson/saved_omc/OMSimulator/install/bin/OMSimulator -r=Modelica_4.0.0_Modelica.Mechanics.MultiBody.Examples.Loops.Engine1a_res.mat --tempDir=temp_Modelica_4_0_0_Modelica_Mechanics_MultiBody_Examples_Loops_Engine1a_fmu --startTime=0 --stopTime=5 --timeout=50 --tolerance=1e-06 Modelica_4_0_0_Modelica_Mechanics_MultiBody_Examples_Loops_Engine1a.fmu > Modelica_4.0.0_Modelica.Mechanics.MultiBody.Examples.Loops.Engine1a.pipe 2>&1)
diffSimulationResults("Modelica_4.0.0_Modelica.Mechanics.MultiBody.Examples.Loops.Engine1a_res.mat","/var/lib/jenkins1/ws/OpenModelicaLibraryTestingWork/Reference-modelica.org/ReferenceResults/MAP-LIB_ReferenceResults/v4.0.0/Modelica/Mechanics/MultiBody/Examples/Loops/Engine1a/Engine1a.csv","/var/lib/jenkins1/ws/OpenModelicaLibraryTestingWork/OpenModelicaLibraryTesting/files/Modelica_4.0.0_Modelica.Mechanics.MultiBody.Examples.Loops.Engine1a.diff",relTol=0.003,relTolDiffMinMax=0.003,rangeDelta=0.001)
Reference file matches